From 074785cea106179cb3305637055ab0a009ca74f2 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:42:52 -0500 Subject: initial commit --- .../web/guide/ajax/como_come\303\247ar/index.html" | 305 ++++++++++++++++++ files/pt-pt/web/guide/ajax/comunidade/index.html | 22 ++ files/pt-pt/web/guide/ajax/index.html | 131 ++++++++ files/pt-pt/web/guide/eventos/index.html | 133 ++++++++ "files/pt-pt/web/guide/gr\303\241ficos/index.html" | 50 +++ .../guide/html/categorias_de_conteudo/index.html | 175 +++++++++++ .../index.html | 343 +++++++++++++++++++++ files/pt-pt/web/guide/index.html | 63 ++++ 8 files changed, 1222 insertions(+) create mode 100644 "files/pt-pt/web/guide/ajax/como_come\303\247ar/index.html" create mode 100644 files/pt-pt/web/guide/ajax/comunidade/index.html create mode 100644 files/pt-pt/web/guide/ajax/index.html create mode 100644 files/pt-pt/web/guide/eventos/index.html create mode 100644 "files/pt-pt/web/guide/gr\303\241ficos/index.html" create mode 100644 files/pt-pt/web/guide/html/categorias_de_conteudo/index.html create mode 100644 files/pt-pt/web/guide/html/utilizar_estruturas_e_seccoes_de_html/index.html create mode 100644 files/pt-pt/web/guide/index.html (limited to 'files/pt-pt/web/guide') diff --git "a/files/pt-pt/web/guide/ajax/como_come\303\247ar/index.html" "b/files/pt-pt/web/guide/ajax/como_come\303\247ar/index.html" new file mode 100644 index 0000000000..f067252d2d --- /dev/null +++ "b/files/pt-pt/web/guide/ajax/como_come\303\247ar/index.html" @@ -0,0 +1,305 @@ +--- +title: Primeiros Passos +slug: Web/Guide/AJAX/Como_começar +tags: + - AJAX + - API + - Avançado + - JavaScript + - Mecânica da Web + - XMLHttpRequest +translation_of: Web/Guide/AJAX/Getting_Started +--- +

Este artigo guia-o através do essencial do AJAX e oferece-lhe dois exemplos práticos simples para poder começar.

+ +

O que é AJAX?

+ +

AJAX (JavaScript Assíncrono e XML) em poucas palavras, é a utilização do objeto XMLHttpRequest para comunicar com os servidores. Este pode enviar e receber informação em vários formatos, incluindo JSON, XML, HTML e ficheiros de texto. A característica mais atraente do AJAX é a sua natureza 'assíncrona', o que significa que este pode comunicar com o servidor, trocar dados, e atualizar a página sem ter que recarregar a página.

+ +

As duas principais funcionalidades do AJAX são as seguintes:

+ + + +

Passo 1 - Como efetuar um pedido de HTTP

+ +

Para fazer uma requisição HTTP ao servidor usando JavaScript, você precisa de uma instância de uma classe que disponibilize essa funcionalidade. Tal classe foi primeiro introduzida no Internet Explorer sob a forma de um objecto ActiveX chamado XMLHTTP. Depois, o Mozilla, o Safari e outros browsers fizeram o mesmo, implementando uma classe de nome XMLHttpRequest que suporta os métodos e as propriedades do objecto ActiveX original da Microsoft.

+ +

Por isso, para criar uma instância (objeto) da classe pretendida compatível com multiplos navegadores, você pode fazer:

+ +
if (window.XMLHttpRequest) { // Mozilla, Safari, ...
+    http_request = new XMLHttpRequest();
+} else if (window.ActiveXObject) { // IE
+    http_request = new ActiveXObject("Microsoft.XMLHTTP");
+}
+
+
+ +

(só a título de exemplo, o código acima é uma versão simplificada do código a ser usado para a criação de uma instância XMLHTTP. Para um exemplo mais "vida real", dê uma olhada ao 3º passo deste artigo.)

+ +

Algumas versões de alguns browsers Mozilla não irão funcionar bem se a resposta do servidor não possuir um cabeçalho mime-type XML. Para satisfazer isto, você pode usar uma chamada extra a um método para ultrapassar o cabeçalho enviado pelo servidor, só no caso de não ser no formato text/xml.

+ +
http_request = new XMLHttpRequest();
+http_request.overrideMimeType('text/xml');
+
+ +

A próxima coisa a ser feita é decidir o que quer fazer após receber a resposta do servidor ao seu pedido. Nesta etapa só precisa de dizer ao objecto pedido HTTP que função JavaScript irá processar a resposta. Isto é feito definindo a propriedade onreadystatechange do objeto ao nome da função JavaScript que pretende utilizar, por exemplo:

+ +

http_request.onreadystatechange = NomedaFunção;

+ +

Note-se que não existem chaves após o nome da função e não são passados parâmetros. Também, em vez de dar um nome a função, você pode usar a técnica JavaScript de definir funções na hora (chamadas funções anônimas) e definir as ações que vão processar a resposta logo, por exemplo:

+ +
http_request.onreadystatechange = function(){
+    // processar resposta do servidor
+};
+
+ +

Em seguida, após ter declarado o que vai acontecer mal receba a resposta, você precisa de consumar o pedido. Precisa de chamar os métodos open() e send() da classe pedido HTTP, por exemplo:

+ +
http_request.open('GET', 'http://www.dominio.com.br/arquivo.extensao', true);
+http_request.send(null);
+
+ + + +

O parâmetro do método send() pode ser costituido por quaisquer dados que pretenda enviar ao servidor ao enviar (POST) o pedido. Os dados devem estar sob a forma de uma linha de texto de pergunta, tipo:

+ +

name=value&anothername=othervalue&so=on

+ +

ou em vários outros formatos, incluindo JSON, SOAP, etc.

+ +

Note-se que se pretende enviar (POST) dados, você deve alterar o tipo MIME do pedido usando a seguinte linha:

+ +
http_request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
+
+ +

De outra forma o servidor irá ignorar os dados (post).

+ +

Pode-se também colocar o charset desejado assim:

+ +
http_request.setRequestHeader('Content-Type',
+                           "application/x-www-form-urlencoded; charset=iso-8859-1");
+
+ +

Outro ponto importante é controle do cache, pois caso haja necessidadde de reenviar a consulta, pode ser que o objeto retorne o que está no cache do navegador. Para evitar esse tipo de transtorno as linhas abaixo eliminam essas possibilidades:

+ +
 http_request.setRequestHeader("Cache-Control",
+                               "no-store, no-cache, must-revalidate");
+http_request.setRequestHeader("Cache-Control",
+                              "post-check=0, pre-check=0");
+http_request.setRequestHeader("Pragma", "no-cache");
+
+ +

Passo 2 - Manipular a resposta do servidor

+ +

Lembre-se que quando estava a enviar o pedido, você providenciou o nome de uma função JavaScript que é criada para lidar com a resposta.

+ +

http_request.onreadystatechange = nameOfTheFunction;

+ +

Vamos a ver o que é que esta função deve fazer. Primeiro, a função precisa de verificar o estado do pedido. Se o estado possui o valor 4, isso significa que a totalidade da resposta do servidor foi recebida e que pode continuar a processá-la à vontade.

+ +
if (http_request.readyState == 4) {
+    // everything is good, the response is received
+} else {
+    // still not ready
+}
+
+ +

A lista completa dos valores readyState é a seguinte:

+ + + +

(Source)

+ +

A próxima coisa a verificar é o código do estado da resposta HTTP do servidor. Todos os códigos possíveis estão listados na página W3C. Para os nossos objectivos nós só estamos interessados na resposta 200 OK.

+ +
if (http_request.status == 200) {
+    // perfect!
+} else {
+    // there was a problem with the request,
+    // for example the response may be a 404 (Not Found)
+    // or 500 (Internal Server Error) response codes
+}
+
+ +

Depois de verificar o estado do pedido e o código do estado HTTP da resposta, compete-lhe a si fazer aquilo que quer fazer com os dados que o servidor lhe enviou. Tem duas opções para aceder a esses dados:

+ + + +

 

+ +

Passo 3 – Um exemplo simples

+ +

Vamos agora pôr tudo junto e efectuar um simples pedido HTTP. O nosso JavaScript vai pedir um documento HTML, teste.html, que contém o texto "Sou um teste." e então vamos alert() os conteúdos do ficheiro teste.html.

+ +
<script type="text/javascript" language="javascript">
+
+    var http_request = false;
+
+    function makeRequest(url) {
+
+        http_request = false;
+
+        if (window.XMLHttpRequest) { // Mozilla, Safari,...
+            http_request = new XMLHttpRequest();
+            if (http_request.overrideMimeType) {
+                http_request.overrideMimeType('text/xml');
+                // See note below about this line
+            }
+        } else if (window.ActiveXObject) { // IE
+            try {
+                http_request = new ActiveXObject("Msxml2.XMLHTTP");
+            } catch (e) {
+                try {
+                    http_request = new ActiveXObject("Microsoft.XMLHTTP");
+                } catch (e) {}
+            }
+        }
+
+        if (!http_request) {
+            alert('Giving up :( Cannot create an XMLHTTP instance');
+            return false;
+        }
+        http_request.onreadystatechange = alertContents;
+        http_request.open('GET', url, true);
+        http_request.send(null);
+
+    }
+
+    function alertContents() {
+
+        if (http_request.readyState == 4) {
+            if (http_request.status == 200) {
+                alert(http_request.responseText);
+            } else {
+                alert('There was a problem with the request.');
+            }
+        }
+
+    }
+</script>
+<span
+    style="cursor: pointer; text-decoration: underline"
+    onclick="makeRequest('test.html')">
+        Make a request
+</span>
+
+ +

Neste exemplo:

+ + + +

Você pode testar o exemplo aqui e pode ver o ficheiro de teste aqui.

+ +
Nota: Se você está enviando uma solicitação para um pedaço de código que retornará XML, ao invés de um arquivo XML estático, é necessário definir alguns cabeçalhos de resposta se a sua página deve trabalhar com o Internet Explorer, além de Mozilla. Se você não definir cabeçalho Content-Type: application / xml, o IE irá lançar um erro JavaScript, "Objeto esperado", após a linha onde você tentar acessar um elemento XML..
+ +
Nota 2: Se você não definir cabeçalho Cache-Control: no-cache o navegador armazenará em cache a resposta e jamais voltará a submeter o pedido, tornando a depuração "desafiadora". Também é possível acrescentar um parâmetro GET adicional sempre diferente, como o timestamp ou um número aleatório (veja bypassing the cache).
+ +
Nota 3: Se a variável httpRequest é utilizada globalmente, funções concorrentes chamando makeRequest () podem sobrescrever o outro, causando uma condição de corrida. Declarando o httpRequest variável local para um closure contendo as funções AJAX impede a condição de corrida.
+ +
Nota 4: Caso ocorra um erro de comunicação (tal como a queda de do servidor web), uma exceção será lançada no método onreadystatechange quando o campo status for acessado. Tenha a certeza de envolver sua declaração if..then dentro de um bloco try...catch. (Veja: {{ Bug(238559) }}).
+ +

Passo 4 – Trabalhar com a resposta XML

+ +

No exemplo anterior, após termos recebido a resposta ao pedido HTTP, nós usamos a propriedade reponseText do objecto de pedido e continha os conteúdos do ficheiro test.html. Agora vamos experimentar a propriedade responseXML.

+ +

Antes de tudo, vamos criar um documento XML válido que vamos pedir mais à frente. O documento (test.xml) contém o seguinte:

+ +

 

+ +
<?xml version="1.0" ?>
+<root>
+    I'm a test.
+</root>
+
+ +

No guião só precisamos de alterar a linha do pedido com:

+ +
...
+onclick="makeRequest('test.xml')">
+...
+
+ +

Então em alertContents() nós precisamos de substituir a linha de alerta (alert(http_request.responseText);) com:

+ +
var xmldoc = http_request.responseXML;
+var root_node = xmldoc.getElementsByTagName('root').item(0);
+alert(root_node.firstChild.data);
+
+ +

Este código pega o objeto XMLDocument obtido por responseXML e utiliza métodos DOM para acessar alguns dados contidos no documento XML. Você pode ver o test.xml aqui e o script de teste atualizado aqui.

+ +

Categorias

+ +

Interwiki Language Links

+ +

Passo 5 – Tabalhar com dados

+ +

Finalmente, vamos enviar algum dado para o servidor e obter a resposta. Desta vez, nosso JavaScript solicitará um página dinâmica (test.php)  que receberá os dados que enviamos e retornará um string computada - "Hello, [user data]!" - visualizada através de alert().

+ +

Primeiro, vamos adicionar uma text box em nosso HTML de modo que o usuário possa digitar o seu nome:

+ +
<label>Your name:
+  <input type="text" id="ajaxTextbox" />
+</label>
+<span id="ajaxButton" style="cursor: pointer; text-decoration: underline">
+  Make a request
+</span>
+ +

Vamos, também, adicionar uma linha para nosso manipulador de eventos obter os dados do usuário da text box e enviá-lo para função makeRequest() juntamente com a URL do nosso script do lado do servidor (server-side):

+ +
document.getElementById("ajaxButton").onclick = function() {
+      var userName = document.getElementById("ajaxTextbox").value;
+      makeRequest('test.php',userName);
+  };
+ +

Precisamos modificar makeRequest () para aceitar os dados do usuário e passá-lo para o servidor. Vamos mudar o método de requisição de GET para POST, e incluir nossos dados como um parâmetro na chamada para httpRequest.send():

+ +
function makeRequest(url, userName) {
+
+    ...
+
+    httpRequest.onreadystatechange = alertContents;
+    httpRequest.open('POST', url);
+    httpRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
+    httpRequest.send('userName=' + encodeURIComponent(userName));
+  }
+
+ +

A função alertContents() pode ser escrita da mesma forma que se encontrava no Passo 3 para alertar (alert()) nossa string computada,  se isso for tudo o que o servidor retorna. No entanto, vamos dizer que  o servidor irá retornar tanto a sequência computada como o dados original do usuário. Portanto, se o usuário digitou "Jane" na text box, a resposta do servidor ficaria assim:

+ +

{"userData":"Jane","computedString":"Hi, Jane!"}

+ +

Para utilizar estes dados dentro de alertContents(), nós não podemos simplesmente exibir com alert()  a propriedade responseText. Temos que analisar (parse it)  computedString a propriedade que queremos:

+ +
function alertContents() {
+    if (httpRequest.readyState === 4) {
+      if (httpRequest.status === 200) {
+        var response = JSON.parse(httpRequest.responseText);
+        alert(response.computedString);
+    } else {
+      alert('There was a problem with the request.');
+    }
+}
+ +

Para mais métodos DOM, certifique-se que consulta os documentos sobre a implementação de DOM da Mozilla

diff --git a/files/pt-pt/web/guide/ajax/comunidade/index.html b/files/pt-pt/web/guide/ajax/comunidade/index.html new file mode 100644 index 0000000000..98a2936999 --- /dev/null +++ b/files/pt-pt/web/guide/ajax/comunidade/index.html @@ -0,0 +1,22 @@ +--- +title: Comunidade +slug: Web/Guide/AJAX/Comunidade +tags: + - AJAX +translation_of: Web/Guide/AJAX/Community +--- +

Se conhece listas de discussão úteis, grupos de notícias, fóruns, ou outras comunidades relacionadas com AJAX, interligue-os aqui.

+ +

Recursos Ajax

+ +

Ajax - Conferências e Cursos

+ + + +

{{ languages( { "ja": "ja/AJAX/Community", "fr": "fr/AJAX/Communaut\u00e9" } ) }}

diff --git a/files/pt-pt/web/guide/ajax/index.html b/files/pt-pt/web/guide/ajax/index.html new file mode 100644 index 0000000000..d994ea7b96 --- /dev/null +++ b/files/pt-pt/web/guide/ajax/index.html @@ -0,0 +1,131 @@ +--- +title: AJAX +slug: Web/Guide/AJAX +tags: + - AJAX + - DOM + - JSON + - JavaScript + - Referências + - XML + - XMLHttRequest +translation_of: Web/Guide/AJAX +--- +

 

+ +
Primeiros Passos + +

Uma introdução ao AJAX

+
+ +
+

JavaScript Assíncrono e XML, enquanto não uma tecnologia em si, é um termo criado em 2005 por Jesse James Garret, que descreve uma "nova" abordagem para utilizar uma série de tecnologias existentes em conjunto, incluindo HTML ou XHTML, Cascading Style Sheets, JavaScript, Document Object Model, XML, XSLT e o objeto XMLHttpRequest.
+ Quando estas tecnologias são combinadas no modelo AJAX, as aplicações da Web são capazes de efetuar atualizações incrementais e rápidas na interface do utilizador sem recarregar toda a página. Isto torna a aplicação mais rápida e mais responsiva para as ações do do utilizador.

+
+ +

Although X in Ajax stands for XML, JSON is used more than XML nowadays because of its many advantages such as being lighter and a part of JavaScript. Both JSON and XML are used for packaging information in Ajax model.

+ +
+
+

Documentação

+ +
+
Primeiros Passos
+
This article guides you through the Ajax basics and gives you two simple hands-on examples to get you started.
+
Utilizar a API XMLHttpRequest
+
The XMLHttpRequest API is the core of Ajax. This article will explain how to use some Ajax techniques, like: + +
+
API Fetch
+
The Fetch API provides an interface for fetching resources. It will seem familiar to anyone who has used {{domxref("XMLHTTPRequest")}}, but this API provides a more powerful and flexible feature set.
+
Eventos de envio do servidor
+
Traditionally, a web page has to send a request to the server to receive new data; that is, the page requests data from the server. With server-sent events, it's possible for a server to send new data to a web page at any time, by pushing messages to the web page. These incoming messages can be treated as Events + data inside the web page. See also: Using server-sent events.
+
Pure-Ajax navigation example
+
This article provides a working (minimalist) example of a pure-Ajax website composed only of three pages.
+
Enviar e Receber Dados Binário
+
The responseType property of the XMLHttpRequest object can be set to change the expected response type from the server. Possible values are the empty string (default), "arraybuffer", "blob", "document", "json", and "text". The response property will contain the entity body according to responseType, as an ArrayBuffer, Blob, Document, JSON, or string. This article will show some Ajax I/O techniques.
+
XML
+
The Extensible Markup Language (XML) is a W3C-recommended general-purpose markup language for creating special-purpose markup languages. It is a simplified subset of SGML, capable of describing many different kinds of data. Its primary purpose is to facilitate the sharing of data across different systems, particularly systems connected via the Internet.
+
JXON
+
JXON stands for lossless Javascript XML Object Notation, it is a generic name by which is defined the representation of Javascript object trees (JSON) using XML.
+
Analisar e serializar XML
+
How to parse an XML document from a string, a file or via javascript and how to serialize XML documents to strings, Javascript Object trees (JXON) or files.
+
XPath
+
XPath stands for XML Path Language, it uses a non-XML syntax that provides a flexible way of addressing (pointing to) different parts of an XML document. As well as this, it can also be used to test addressed nodes within a document to determine whether they match a pattern or not.
+
A API FileReader
+
The FileReader API lets web applications asynchronously read the contents of files (or raw data buffers) stored on the user's computer, using File or Blob objects to specify the file or data to read. File objects may be obtained from a FileList object returned as a result of a user selecting files using the <input> element, from a drag and drop operation's DataTransfer object, or from the mozGetAsFile() API on an HTMLCanvasElement.
+
HTML no XMLHttpRequest
+
The W3C XMLHttpRequest specification adds HTML parsing support to XMLHttpRequest, which originally supported only XML parsing. This feature allows Web apps to obtain an HTML resource as a parsed DOM using XMLHttpRequest.
+
Outros recursos
+
Outros recursos Ajax que poderão ser úteis.
+
+ +

Ver Todos...

+ +

Consulte também

+ +
+
Alternate Ajax Techniques
+
Most articles on Ajax have focused on using XMLHttp as the means to achieving such communication, but Ajax techniques are not limited to just XMLHttp. There are several other methods.
+
Ajax: A New Approach to Web Applications
+
Jesse James Garrett, of adaptive path, wrote this article in February 2005, introducing Ajax and its related concepts.
+
A Simpler Ajax Path
+
"As it turns out, it's pretty easy to take advantage of the XMLHttpRequest object to make a web app act more like a desktop app while still using traditional tools like web forms for collecting user input."
+
Ajax Mistakes
+
Alex Bosworth has written this article outlining some of the mistakes Ajax application developers can make.
+
Tutorial with examples.
+
 
+
XMLHttpRequest specification
+
W3C Working draft
+
+
+ +
+

Comunidade

+ +
    +
  • View Mozilla forums...
    • +
+ +
{{ DiscussionList("dev-ajax", "mozilla.dev.ajax") }}
+ + + +

Ferramentas

+ + + +

View All...

+ +

Exemplos

+ + + + + +

HTML, XHTML, CSS, DOM, JavaScript, XML, XMLHttpRequest, XSLT, DHTML, Same Origin Policy

+
+
+ +

{{ListSubpages}}

diff --git a/files/pt-pt/web/guide/eventos/index.html b/files/pt-pt/web/guide/eventos/index.html new file mode 100644 index 0000000000..99e7f2f492 --- /dev/null +++ b/files/pt-pt/web/guide/eventos/index.html @@ -0,0 +1,133 @@ +--- +title: Guia do programador de eventos +slug: Web/Guide/Eventos +tags: + - DOM + - Evento + - Guía + - Precisa de Atualização +translation_of: Web/Guide/Events +--- +

{{draft()}}

+ +

Events refers both to a design pattern used for the asynchronous handling of various incidents which occur in the lifetime of a web page and to the naming, characterization, and use of a large number of incidents of different types.

+ +

The overview page provides an introduction to the design pattern and a summary of the types of incidents which are defined and reacted to by modern web browsers.

+ +

The custom events page describes how the event code design pattern can be used in custom code to define new event types emitted by user objects, register listener functions to handle those events, and trigger the events in user code.

+ +

The remaining pages describe how to use events of different kinds defined by web browsers. Unfortunately, these events have been defined piece by piece as web browsers have evolved so that there is no satisfying systematic characterization of the events built-in or defined by modern web browsers.

+ +

The device on which the web browser is running can trigger events, for example due to a change in its position and orientation in the real world, as discussed partially by the page on orientation coordinate systems and the page on the use of 3D transforms. That is different, but similar, to the change in device vertical orientation. 

+ +

The window in which the browser is displayed can trigger events; for example, change size if the user maximizes the window or otherwise changes it.

+ +

The process loading of a web page can trigger events in response to the completion of different steps in the downloading, parsing, and rendering of the web page for display to the user.

+ +

The user interaction with the web page contents can trigger events. The events triggered by user interaction evolved during the early years of browser design and include a complicated system defining the sequence in which events will be called and the manner in which that sequence can be controlled. The different types of user interaction-driven events include:

+ + + +

The modification of the web page in structure or content might trigger some events, as explained in the mutation events page, but the use of these events has been deprecated in favour of the lighter Mutation Observer approach.

+ +

The media streams embedded in the HTML documents might trigger some events, as explained in the media events page.

+ +

The network requests made by a web page might trigger some events.

+ +

There are many other sources of events defined by web browsers for which pages are not yet available in this guide.

+ +
+

Note: This Event Developer Guide needs substantial work. The structure needs to be reorganized and the pages rewritten. Our hope is that everything you need to know about events will go under here.

+
+ +

Documentos

+ +

{{LandingPageListSubpages}}

+ +
+ + + + + +
diff --git "a/files/pt-pt/web/guide/gr\303\241ficos/index.html" "b/files/pt-pt/web/guide/gr\303\241ficos/index.html" new file mode 100644 index 0000000000..c18d703bc5 --- /dev/null +++ "b/files/pt-pt/web/guide/gr\303\241ficos/index.html" @@ -0,0 +1,50 @@ +--- +title: Gráficos na Web +slug: Web/Guide/Gráficos +tags: + - 2D + - 3D + - Canvas + - HTML5 + - SVG + - Tela + - Web + - WebGL + - WebRTC + - graficos +translation_of: Web/Guide/Graphics +--- +

Web sites e aplicações necessitam frequentemente de apresentar gráficos. Imagens estáticas podem ser facilmente mostradas usado o elemento {{HTMLElement("img")}}, ou definindo o fundo do elemento HTML com a propriedade {{cssxref("background-image")}}. É ainda possivel construir gráficos no momento, ou manipular imagens. Este artigo disponibiliza toda a informação necessária.  

+ +
+
+

Gráficos 2D

+ +
+
Canvas
+
O elemento {{HTMLElement("canvas")}} fornece APIs para desenhar gráficos em 2D com recurso a JavaScript.
+
SVG
+
Scalable Vector Graphics (SVG) utiliza linhas, curvas, e outras formas geometricas para criar gráficos. Com vetores, pode ainda criar imagens que escalam para qualquer tamanho.
+
+ +

View All...

+
+ +
+

Gráficos 3D

+ +
+
WebGL
+
Um guia para iniciar com WebGL, o API de gráficos 3D para a Web. Esta tecnologia permite o uso do standard OpenGL ES em conteúdos Web.
+
+ +

Vídeo

+ +
+
Utilizar áudio e vídeo em HTML5
+
Incorporar video e/ou audio numa página web e controlar a sua reprodução.
+
WebRTC
+
O RTC em WebRTC significa Real-Time Communications (Comunicação em Tempo Real), é a tecnologia que permite o streaming the audio/video e partilha de informação entre clientes de browser (peers).
+
+
+
diff --git a/files/pt-pt/web/guide/html/categorias_de_conteudo/index.html b/files/pt-pt/web/guide/html/categorias_de_conteudo/index.html new file mode 100644 index 0000000000..9a7c08ee9a --- /dev/null +++ b/files/pt-pt/web/guide/html/categorias_de_conteudo/index.html @@ -0,0 +1,175 @@ +--- +title: Categorias de conteúdo +slug: Web/Guide/HTML/Categorias_de_conteudo +tags: + - Avançado + - Guía + - HTML + - HTML5 + - Web +translation_of: Web/Guide/HTML/Content_categories +--- +

Every HTML element is a member of one or more content categories, which group elements that share characteristics. This is a loose grouping (it doesn't actually create a relationship among elements of these categories), but they help define and describe the categories' shared behavior and their associated rules, especially when you come upon their intricate details. It's also possible for elements to not be a member of any of these categories.

+ +

There are three types of content categories:

+ + + +
+

Nota: A more detailed discussion of these content categories and their comparative functionalities is beyond the scope of this article; for that, you may wish to read the relevant portions of the HTML specification.

+
+ +

A Venn diagram showing how the various content categories interrelate. The following sections explain these relationships in text.

+ +

Main content categories

+ +

Metadata content

+ +

Elements belonging to the metadata content category modify the presentation or the behavior of the rest of the document, set up links to other documents, or convey other out of band information.

+ +

Elements belonging to this category are {{HTMLElement("base")}}, {{ Obsolete_inline() }}{{HTMLElement("command")}}, {{HTMLElement("link")}}, {{HTMLElement("meta")}}, {{HTMLElement("noscript")}}, {{HTMLElement("script")}}, {{HTMLElement("style")}} and {{HTMLElement("title")}}.

+ +

Flow content

+ +

Elements belonging to the flow content category typically contain text or embedded content. They are: {{HTMLElement("a")}}, {{HTMLElement("abbr")}}, {{HTMLElement("address")}}, {{HTMLElement("article")}}, {{HTMLElement("aside")}}, {{HTMLElement("audio")}}, {{HTMLElement("b")}},{{HTMLElement("bdo")}}, {{HTMLElement("bdi")}}, {{HTMLElement("blockquote")}}, {{HTMLElement("br")}}, {{HTMLElement("button")}}, {{HTMLElement("canvas")}}, {{HTMLElement("cite")}}, {{HTMLElement("code")}}, {{ Obsolete_inline() }}{{HTMLElement("command")}}, {{HTMLElement("data")}}, {{HTMLElement("datalist")}}, {{HTMLElement("del")}}, {{HTMLElement("details")}}, {{HTMLElement("dfn")}}, {{HTMLElement("div")}}, {{HTMLElement("dl")}}, {{HTMLElement("em")}}, {{HTMLElement("embed")}}, {{HTMLElement("fieldset")}}, {{HTMLElement("figure")}}, {{HTMLElement("footer")}}, {{HTMLElement("form")}}, {{HTMLElement("h1")}}, {{HTMLElement("h2")}}, {{HTMLElement("h3")}}, {{HTMLElement("h4")}}, {{HTMLElement("h5")}}, {{HTMLElement("h6")}}, {{HTMLElement("header")}}, {{HTMLElement("hgroup")}}, {{HTMLElement("hr")}}, {{HTMLElement("i")}}, {{HTMLElement("iframe")}}, {{HTMLElement("img")}}, {{HTMLElement("input")}}, {{HTMLElement("ins")}}, {{HTMLElement("kbd")}}, {{deprecated_inline()}}{{HTMLElement("keygen")}}, {{HTMLElement("label")}}, {{HTMLElement("main")}}, {{HTMLElement("map")}}, {{HTMLElement("mark")}}, {{MathMLElement("math")}}, {{HTMLElement("menu")}}, {{HTMLElement("meter")}}, {{HTMLElement("nav")}}, {{HTMLElement("noscript")}}, {{HTMLElement("object")}}, {{HTMLElement("ol")}}, {{HTMLElement("output")}}, {{HTMLElement("p")}}, {{HTMLElement("pre")}}, {{HTMLElement("progress")}}, {{HTMLElement("q")}}, {{HTMLElement("ruby")}}, {{HTMLElement("s")}}, {{HTMLElement("samp")}}, {{HTMLElement("script")}}, {{HTMLElement("section")}}, {{HTMLElement("select")}}, {{HTMLElement("small")}}, {{HTMLElement("span")}}, {{HTMLElement("strong")}}, {{HTMLElement("sub")}}, {{HTMLElement("sup")}}, {{SVGElement("svg")}}, {{HTMLElement("table")}}, {{HTMLElement("template")}}, {{HTMLElement("textarea")}}, {{HTMLElement("time")}}, {{HTMLElement("ul")}}, {{HTMLElement("var")}}, {{HTMLElement("video")}}, {{HTMLElement("wbr")}} and Text.

+ +

A few other elements belong to this category, but only if a specific condition is fulfilled:

+ + + +

Sectioning content

+ +

Elements belonging to the sectioning content model create a section in the current outline that defines the scope of {{HTMLElement("header")}} elements, {{HTMLElement("footer")}} elements, and heading content.

+ +

Elements belonging to this category are {{HTMLElement("article")}}, {{HTMLElement("aside")}}, {{HTMLElement("nav")}} and {{HTMLElement("section")}}.

+ +
+

Do not confuse this content model with the sectioning root category, which isolates its content from the regular outline.

+
+ +

Heading content

+ +

Heading content defines the title of a section, whether marked by an explicit sectioning content element, or implicitly defined by the heading content itself.

+ +

Elements belonging to this category are {{HTMLElement("h1")}}, {{HTMLElement("h2")}}, {{HTMLElement("h3")}}, {{HTMLElement("h4")}}, {{HTMLElement("h5")}}, {{HTMLElement("h6")}} and {{HTMLElement("hgroup")}}.

+ +
+

Though likely to contain heading content, the {{HTMLElement("header")}} is not heading content itself.

+
+ +
+

Note: The {{HTMLElement("hgroup")}} element was removed from the W3C HTML specification prior to HTML 5 being finalized, but is still part of the WHATWG specification and is at least partially supported by most browsers.

+
+ +

Phrasing content

+ +

Phrasing content defines the text and the mark-up it contains. Runs of phrasing content make up paragraphs.

+ +

Elements belonging to this category are {{HTMLElement("abbr")}}, {{HTMLElement("audio")}}, {{HTMLElement("b")}}, {{HTMLElement("bdo")}}, {{HTMLElement("br")}}, {{HTMLElement("button")}}, {{HTMLElement("canvas")}}, {{HTMLElement("cite")}}, {{HTMLElement("code")}}, {{ Obsolete_inline() }}{{HTMLElement("command")}}, {{HTMLElement("data")}}, {{HTMLElement("datalist")}}, {{HTMLElement("dfn")}}, {{HTMLElement("em")}}, {{HTMLElement("embed")}}, {{HTMLElement("i")}}, {{HTMLElement("iframe")}}, {{HTMLElement("img")}}, {{HTMLElement("input")}}, {{HTMLElement("kbd")}}, {{deprecated_inline()}}{{HTMLElement("keygen")}}, {{HTMLElement("label")}}, {{HTMLElement("mark")}}, {{MathMLElement("math")}}, {{HTMLElement("meter")}}, {{HTMLElement("noscript")}}, {{HTMLElement("object")}}, {{HTMLElement("output")}}, {{HTMLElement("progress")}}, {{HTMLElement("q")}}, {{HTMLElement("ruby")}}, {{HTMLElement("samp")}}, {{HTMLElement("script")}}, {{HTMLElement("select")}}, {{HTMLElement("small")}}, {{HTMLElement("span")}}, {{HTMLElement("strong")}}, {{HTMLElement("sub")}}, {{HTMLElement("sup")}}, {{SVGElement("svg")}}, {{HTMLElement("textarea")}}, {{HTMLElement("time")}}, {{HTMLElement("var")}}, {{HTMLElement("video")}}, {{HTMLElement("wbr")}} and plain text (not only consisting of white spaces characters).

+ +

A few other elements belong to this category, but only if a specific condition is fulfilled:

+ + + +

Embedded content

+ +

Embedded content imports another resource or inserts content from another mark-up language or namespace into the document. Elements that belong to this category include: {{HTMLElement("audio")}}, {{HTMLElement("canvas")}}, {{HTMLElement("embed")}}, {{HTMLElement("iframe")}}, {{HTMLElement("img")}}, {{MathMLElement("math")}}, {{HTMLElement("object")}}, {{SVGElement("svg")}}, {{HTMLElement("video")}}.

+ +

Interactive content

+ +

Interactive content includes elements that are specifically designed for user interaction. Elements that belong to this category include: {{HTMLElement("a")}}, {{HTMLElement("button")}}, {{HTMLElement("details")}}, {{HTMLElement("embed")}}, {{HTMLElement("iframe")}}, {{deprecated_inline()}}{{HTMLElement("keygen")}}, {{HTMLElement("label")}}, {{HTMLElement("select")}}, and {{HTMLElement("textarea")}}.
+ Some elements belong to this category only under specific conditions:

+ + + +

Palpable content

+ +

Content is palpable when it's neither empty or hidden; it is content that is rendered and is substantive. Elements whose model is flow content or phrasing content should have at least one node which is palpable.

+ +

Form-associated content

+ +

Form-associated content comprises elements that have a form owner, exposed by a form attribute. A form owner is either the containing {{HTMLElement("form")}} element or the element whose id is specified in the form attribute.

+ + + +

This category contains several sub-categories:

+ +
+
listed
+
Elements that are listed in the form.elements and fieldset.elements IDL collections. Contains {{HTMLElement("button")}}, {{HTMLElement("fieldset")}}, {{HTMLElement("input")}}, {{deprecated_inline()}}{{HTMLElement("keygen")}}, {{HTMLElement("object")}}, {{HTMLElement("output")}}, {{HTMLElement("select")}}, and {{HTMLElement("textarea")}}.
+
labelable
+
Elements that can be associated with {{HTMLElement("label")}} elements. Contains {{HTMLElement("button")}}, {{HTMLElement("input")}}, {{deprecated_inline()}}{{HTMLElement("keygen")}}, {{HTMLElement("meter")}}, {{HTMLElement("output")}}, {{HTMLElement("progress")}}, {{HTMLElement("select")}}, and {{HTMLElement("textarea")}}.
+
submittable
+
Elements that can be used for constructing the form data set when the form is submitted. Contains {{HTMLElement("button")}}, {{HTMLElement("input")}}, {{deprecated_inline()}}{{HTMLElement("keygen")}}, {{HTMLElement("object")}}, {{HTMLElement("select")}}, and {{HTMLElement("textarea")}}.
+
resettable
+
Elements that can be affected when a form is reset. Contains {{HTMLElement("input")}}, {{deprecated_inline()}}{{HTMLElement("keygen")}}, {{HTMLElement("output")}},{{HTMLElement("select")}}, and {{HTMLElement("textarea")}}.
+
+ +

Secondary categories

+ +

There are some secondary classifications of elements that can be useful to be aware of as well.

+ +

Script-supporting elements

+ +

Script-supporting elements are elements which don't directly contribute to the rendered output of a document. Instead, they serve to support scripts, either by containing or specifying script code directly, or by specifying data that will be used by scripts.

+ +

The script-supporting elements are:

+ + + +

Transparent content model

+ +

If an element has a transparent content model, then its contents must be structured such that they would be valid HTML 5, even if the transparent element were removed and replaced by the child elements.

+ +

For example, the {{HTMLElement("del")}} and {{HTMLELement("ins")}} elements are transparent:

+ +
<p>We hold these truths to be <del><em>sacred &amp; undeniable</em></del> <ins>self-evident</ins>.</p>
+
+ +

If those elements were removed, this fragment would still be valid HTML (if not correct English).

+ +
<p>We hold these truths to be <em>sacred &amp; undeniable</em> self-evident.</p>
+
+ +

Outros modelos de conteúdo

+ +

Seção raiz.

diff --git a/files/pt-pt/web/guide/html/utilizar_estruturas_e_seccoes_de_html/index.html b/files/pt-pt/web/guide/html/utilizar_estruturas_e_seccoes_de_html/index.html new file mode 100644 index 0000000000..fd11f62887 --- /dev/null +++ b/files/pt-pt/web/guide/html/utilizar_estruturas_e_seccoes_de_html/index.html @@ -0,0 +1,343 @@ +--- +title: Utilizar estruturas e secções de HTML +slug: Web/Guide/HTML/Utilizar_estruturas_e_seccoes_de_HTML +tags: + - Avançado + - Estruturas + - Exemplo + - Guía + - HTML + - HTML5 + - Resumo + - Secções + - Sinopse + - Web +translation_of: Web/Guide/HTML/Using_HTML_sections_and_outlines +--- +
+

Importante: atualmente, não existem implementações conhecidas do algoritmo de estrutura nos navegadores gráficos ou agentes de utilizador da tecnologia assistiva, embora o algoritmo esteja implementado noutro software, tal como verificadores de conformidade . Assim, o algoritmo de estrutura não pode ser invocado para transmitir a estrutura do documento aos utilizadores. Recomenda-se que os autores utilizem rank (h1-h6) para transmitir a estrutura do documento.

+
+ +

The HTML5 specification brings several new elements to web developers allowing them to describe the structure of a web document with standard semantics. This document describes these elements and how to use them to define the desired outline for any document.

+ +

Estrutura de um documento em HTML 4

+ +

A estrutura de um documento, por exemplo, a estrutura de semântica do que está entre <body> e </body>, é fundamental para apresentar a página ao utilizador. HTML4 uses the notion of sections and sub-sections of a document to describe its structure. A section is defined by a ({{HTMLElement("div")}}) element with heading elements ({{HTMLElement("h1")}}, {{HTMLElement("h2")}}, {{HTMLElement("h3")}}, {{HTMLElement("h4")}}, {{HTMLElement("h5")}}, or {{HTMLElement("h6")}}) within it, defining its title. The relationships of these elements leads to the structure of the document and its outline.

+ +

So the following mark-up:

+ +
+
<div class="section" id="forest-elephants" >
+  <h1>Forest elephants</h1>
+  <p>In this section, we discuss the lesser known forest elephants.
+    ...this section continues...
+  <div class="subsection" id="forest-habitat" >
+    <h2>Habitat</h2>
+    <p>Forest elephants do not live in trees but among them.
+     ...this subsection continues...
+  </div>
+</div>
+
+
+ +

leads to the following outline (without the implicit level numbers displayed):

+ +
1. Forest elephants
+   1.1 Habitat
+
+ +

The {{HTMLElement("div")}} elements aren't mandatory to define a new section. The mere presence of a heading element is enough to imply a new section. Therefore,

+ +
<h1>Forest elephants</h1>
+  <p>In this section, we discuss the lesser known forest elephants.
+    ...this section continues...
+  <h2>Habitat</h2>
+  <p>Forest elephants do not live in trees but among them.
+    ...this subsection continues...
+  <h2>Diet</h2>
+<h1>Mongolian gerbils</h1>
+
+ +

leads to the following outline:

+ +
1. Forest elephants
+   1.1 Habitat
+   1.2 Diet
+2. Mongolian gerbils
+
+ +

Problemas resolvidos pelo HTML5

+ +

The HTML 4 definition of the structure of a document and its implied outlining algorithm is very rough and leads to numerous problems:

+ +
    +
  1. Usage of {{HTMLElement("div")}} for defining semantic sections, without defining specific values for the class attributes makes the automation of the outlining algorithm impossible ("Is that {{HTMLElement("div")}} part of the outline of the page, defining a section or a subsection?" Or "is it only a presentational {{HTMLElement("div")}}, only used for styling?"). In other terms, the HTML4 spec is very imprecise on what is a section and how its scope is defined. Automatic generation of outlines is important, especially for assistive technology, that are likely to adapt the way they present information to the users according to the structure of the document. HTML5 removes the need for {{HTMLElement("div")}} elements from the outlining algorithm by introducing a new element, {{HTMLElement("section")}}, the HTML Section Element.
    2. +
  2. Merging several documents is hard: inclusion of a sub-document in a main document means changing the level of the HTML Headings Element so that the outline is kept. This is solved in HTML5 as the newly introduced sectioning elements ({{HTMLElement("article")}}, {{HTMLElement("section")}}, {{HTMLElement("nav")}} and {{HTMLElement("aside")}}) are always subsections of their nearest ancestor section, regardless of what sections are created by internal headings.
    3. +
  3. In HTML4, every section is part of the document outline. But documents are often not that linear. A document can have special sections containing information that is not part of, though it is related to, the main flow, like an advertisement block or an explanation box. HTML5 introduces the {{HTMLElement("aside")}} element allowing such sections to not be part of the main outline.
    4. +
  4. Again, in HTML4, because every section is part of the document outline, there is no way to have sections containing information related not to the document but to the whole site, like logos, menus, table of contents, or copyright information and legal notices. For that purpose, HTML5 introduces three new elements: {{HTMLElement("nav")}} for collections of links, such as a table of contents, {{HTMLElement("footer")}} and {{HTMLElement("header")}} for site-related information. Note that {{HTMLElement("header")}} and {{HTMLElement("footer")}} are not sectioning content like {{HTMLElement("section")}}, rather, they exist to semantically mark up parts of a section.
    5. +
+ +

More generally, HTML5 brings precision to the sectioning and heading features, allowing document outlines to be predictable and used by the browser to improve the user experience.

+ +

O algoritmo de estrutura de HTML5

+ +

Let's consider the algorithms  underlying the way HTML handles sections and outlines.

+ +

Definir secções

+ +

All content lying inside the {{HTMLElement("body")}} element is part of a section. Sections in HTML5 can be nested. Beside the main section, defined by the {{HTMLElement("body")}} element, section limits are defined either explicitly or implicitly. Explicitly-defined sections are the content within {{HTMLElement("body")}},  {{HTMLElement("section")}},  {{HTMLElement("article")}},  {{HTMLElement("aside")}}, and {{HTMLElement("nav")}} tags. 

+ +
Each section can have its own heading hierarchy. Therefore, even a nested section can have an {{HTMLElement("h1")}}. See {{anch("Defining headings")}}
+ +

Let's look at an example — here we have a document with a top level section and a footer defined. Inside the top level section we have three subsections, defined by two {{htmlelement("section")}} elements and an {{htmlelement("aside")}} element:

+ +
<section>
+
+  <h1>Forest elephants</h1>
+
+  <section>
+    <h1>Introduction</h1>
+    <p>In this section, we discuss the lesser known forest elephants.</p>
+  </section>
+
+  <section>
+    <h1>Habitat</h1>
+    <p>Forest elephants do not live in trees but among them.</p>
+  </section>
+
+  <aside>
+    <p>advertising block</p>
+  </aside>
+
+</section>
+
+<footer>
+  <p>(c) 2010 The Example company</p>
+</footer>
+ +

This leads to the following outline:

+ +
1. Forest elephants
+   1.1 Introduction
+   1.2 Habitat
+
+ +

Definir cabeçalhos

+ +

While the HTML Sectioning elements define the structure of the document, an outline also needs headings to be useful. The basic rule is simple: the first HTML heading element (one of {{HTMLElement("h1")}}, {{HTMLElement("h2")}}, {{HTMLElement("h3")}}, {{HTMLElement("h4")}}, {{HTMLElement("h5")}}, {{HTMLElement("h6")}}) defines the heading of the current section.

+ +

The heading elements have a rank given by the number in the element name, where {{HTMLElement("h1")}} has the highest rank, and {{HTMLElement("h6")}} has the lowest rank. Relative ranking matters only within a section; the structure of the sections determines the outline, not the heading rank of the sections. For example, consider this code:

+ +
<section>
+  <h1>Forest elephants</h1>
+  <p>In this section, we discuss the lesser known forest elephants.
+    ...this section continues...
+  <section>
+    <h2>Habitat</h2>
+    <p>Forest elephants do not live in trees but among them.
+        ...this subsection continues...
+  </section>
+</section>
+<section>
+  <h3>Mongolian gerbils</h3>
+  <p>In this section, we discuss the famous mongolian gerbils.
+     ...this section continues...
+</section>
+ +

This creates the following outline:

+ +
1. Forest elephants
+   1.1 Habitat
+2. Mongolian gerbils
+ +

Note that the rank of the heading element (in the example {{HTMLElement("h1")}} for the first top-level section, {{HTMLElement("h2")}} for the subsection and {{HTMLElement("h3")}} for the second top-level section) is not important. (Any rank can be used as the heading of an explicitly-defined section, although this practice is not recommended.)

+ +

Implicit sectioning

+ +

Because the HTML5 Sectioning Elements aren't mandatory to define an outline, to keep compatibility with the existing web dominated by HTML4, there is a way to define sections without them. This is called implicit sectioning.

+ +

The heading elements ({{HTMLElement("h1")}} to {{HTMLElement("h6")}}) define a new, implicit section when they aren't the first heading of their parent, explicit, sections. The way this implicit section is positioned in the outline is defined by its relative rank with the previous heading in its parent section. If it is of a lower rank than the previous heading, it opens an implicit sub-section of the section. This code:

+ +
<section>
+  <h1>Forest elephants</h1>
+  <p>In this section, we discuss the lesser known forest elephants.
+    ...this section continues...
+  <h3 class="implicit subsection">Habitat</h3>
+  <p>Forest elephants do not live in trees but among them.
+    ...this subsection continues...
+</section>
+ +

leading to the following outline:

+ +
1. Forest elephants
+   1.1 Habitat (implicitly defined by the h3 element)
+
+ +

If it is of the same rank as the previous heading, it closes the previous section (which may have been explicit!) and opens a new implicit one at the same level: 

+ +
<section>
+  <h1>Forest elephants</h1>
+  <p>In this section, we discuss the lesser known forest elephants.
+    ...this section continues...
+  <h1 class="implicit section">Mongolian gerbils</h1>
+  <p>Mongolian gerbils are cute little mammals.
+    ...this section continues...
+</section>
+ +

leading to the following outline: 

+ +
1. Forest elephants
+2. Mongolian gerbils (implicitly defined by the h1 element, which closed the previous section at the same time)
+
+ +

If it is of a higher rank than the previous heading, it closes the previous section and opens a new implicit one at the higher level:

+ +
<body>
+  <h1>Mammals</h1>
+  <h2>Whales</h2>
+  <p>In this section, we discuss the swimming whales.
+    ...this section continues...
+  <section>
+    <h3>Forest elephants</h3>
+    <p>In this section, we discuss the lesser known forest elephants.
+      ...this section continues...
+    <h3>Mongolian gerbils</h3>
+      <p>Hordes of gerbils have spread their range far beyond Mongolia.
+         ...this subsection continues...
+    <h2>Reptiles</h2>
+      <p>Reptiles are animals with cold blood.
+          ...this section continues...
+  </section>
+</body>
+ +

leading to the following outline:

+ +
1. Mammals
+   1.1 Whales (implicitly defined by the h2 element)
+   1.2 Forest elephants (explicitly defined by the section element)
+   1.3 Mongolian gerbils (implicitly defined by the h3 element, which closes the previous section at the same time)
+2. Reptiles (implicitly defined by the h2 element, which closes the previous section at the same time)
+
+ +

This is not the outline that one might expect by quickly glancing at the heading tags. To make your markup human-understandable, it is a good practice to use explicit tags for opening and closing sections, and to match the heading rank to the intended section nesting level. However, this is not required by the HTML5 specification. If you find that browsers are rendering your document outline in unexpected ways, check whether you have sections that are implicitly closed by heading elements.

+ +

An exception to the rule of thumb that heading rank should match the section nesting level is for sections that may be reused in multiple documents. For example, a section might be stored in a content-management system and assembled into documents at run time. In this case, a good practice is to start at {{HTMLElement("h1")}} for the top heading level of the reusable section. The nesting level of the reusable section will be determined by the section hierarchy of the document in which it appears. Explicit section tags are still helpful in this case.

+ +

Sectioning roots

+ +

 A sectioning root is an HTML element that can have its own outline, but the sections and headings inside it do not contribute to the outline of its ancestor. Beside {{HTMLElement("body")}} which is the logical sectioning root of a document, these are often elements that introduce external content to the page: {{HTMLElement("blockquote")}}, {{HTMLElement("details")}}, {{HTMLElement("fieldset")}}, {{HTMLElement("figure")}} and {{HTMLElement("td")}}.

+ +

Example:

+ +
<section>
+  <h1>Forest elephants</h1>
+  <section>
+    <h2>Introduction</h2>
+    <p>In this section, we discuss the lesser known forest elephants</p>
+  </section>
+  <section>
+    <h2>Habitat</h2>
+    <p>Forest elephants do not live in trees but among them. Let's
+       look what scientists are saying in "<cite>The Forest Elephant in Borneo</cite>":</p>
+    <blockquote>
+       <h1>Borneo</h1>
+       <p>The forest element lives in Borneo...</p>
+    </blockquote>
+  </section>
+</section>
+
+ +

This example results in the following outline:

+ +
1. Forest elephants
+   1.1 Introduction
+   1.2 Habitat
+ +

This outline doesn't contain the internal outline of the {{HTMLElement("blockquote")}} element, which, being an external citation, is a sectioning root and isolates its internal outline.

+ +

Sections outside the outline

+ +

 HTML5 introduces two new elements that allow defining sections that don't belong to the main outline of a web document:

+ +
    +
  1. The HTML Aside Section Element ({{HTMLElement("aside")}}) defines a section that, though related to the main element, doesn't belong to the main flow, like an explanation box or an advertisement. It has its own outline, but doesn't belong to the main one.
    2. +
  2. The HTML Navigational Section Element ({{HTMLElement("nav")}}) defines a section that contains navigation links. There can be several of them in a document, for example one with page internal links like a table of contents, and another with site navigational links. These links are not part of the main document flow and outline, and are generally not initially rendered by screen readers and similar assistive technologies.
    3. +
+ +

Cabeçalhos e Rodapés

+ +

HTML5 also introduces two new elements that can be used to mark up the header and the footer of a section:

+ +
    +
  1. The HTML Header Element ({{HTMLElement("header")}}) defines a page header — typically containing the logo and name of the site and possibly a horizontal menu — or section header, containing perhaps the section's heading, author name, etc. {{HTMLElement("article")}}, {{HTMLElement("section")}}, {{HTMLElement("aside")}}, and {{HTMLElement("nav")}} can have their own {{HTMLElement("header")}}. Despite its name, it is not necessarily positioned at the beginning of the page or section.
    2. +
  2. The HTML Footer Element ({{HTMLElement("footer")}}) defines a page footer — typically containing the copyright and legal notices and sometimes some links — or section footer, containing perhaps the section's publication date, license information, etc. {{HTMLElement("article")}}, {{HTMLElement("section")}}, {{HTMLElement("aside")}}, and {{HTMLElement("nav")}} can have their own {{HTMLElement("footer")}}. Despite its name, it is not necessarily positioned at the end of the page or section.
    3. +
+ +

These do not create new sections in the outline, rather, they mark up content inside sections of the page.

+ +

Addresses in sectioning elements

+ +

The author of a document often wants to publish some contact information, such as the author's name and address. HTML4 allowed this via the {{HTMLElement("address")}} element, which has been extended in HTML5.

+ +

A document can be made of different sections from different authors. A section from another author than the one of the main page is defined using the {{HTMLElement("article")}} element. Consequently, the {{HTMLElement("address")}} element is now linked to its nearest {{HTMLElement("body")}} or {{HTMLElement("article")}} ancestor.

+ +

Utilizar elementos de HTML5 nos navegadores não HTML5

+ +

Sections and headings elements should work in most non-HTML5 browsers. Though unsupported, they don't need a special DOM interface and they only need a specific CSS styling as unknown elements are styled as display:inline by default:

+ +
article, aside, footer, header, hgroup, nav, section {
+  display:block;
+}
+
+ +

Of course the web developer can style them differently, but keep in mind that in a non-HTML5 browser, the default styling is different from what is expected for such elements. Also note that the {{HTMLElement("time")}} element has not been included, because the default styling for it in a non-HTML5 browser is the same as the one in an HTML5-compatible one.

+ +

This method has its limitation though, as some browsers do not allow styling of unsupported elements. That is the case of the Internet Explorer (version 8 and earlier), which need a specific script to allow this:

+ +
<!--[if lt IE 9]>
+  <script>
+    document.createElement("article");
+    document.createElement("aside");
+    document.createElement("footer");
+    document.createElement("header");
+    document.createElement("hgroup");
+    document.createElement("nav");
+    document.createElement("section");
+    document.createElement("time");
+  </script>
+<![endif]-->
+
+ +

This script means that, in the case of Internet Explorer (8 and earlier), scripting should be enabled in order to display HTML5 sectioning and headings elements properly. If not, they won't be displayed, which may be problematic as these elements are likely defining the structure of the whole page. That's why an explicit {{HTMLElement("noscript")}} element should be added inside the {{HTMLElement("head")}} element for this case:

+ +
<noscript>
+  <p><strong>This web page requires JavaScript to be enabled.</strong></p>
+  <p>JavaScript is an object-oriented computer programming language
+    commonly used to create interactive effects within web browsers.</p>
+  <p><a href="https://goo.gl/koeeaJ">How to enable JavaScript?</a></p>
+</noscript>
+
+ +

This leads to the following code to allow the support of the HTML5 sections and headings elements in non-HTML5 browsers, even for Internet Explorer (8 and older), with a proper fallback for the case where this latter browser is configured not to use scripting:

+ +
<!--[if lt IE 9]> <script>
+  document.createElement("article");
+    document.createElement("aside");
+    document.createElement("footer");
+    document.createElement("header");
+    document.createElement("hgroup");
+    document.createElement("nav");
+    document.createElement("section");
+    document.createElement("time");   </script> <![endif]--> <noscript>
+  <p><strong>This web page requires JavaScript to be enabled.</strong></p>
+  <p>JavaScript is an object-oriented computer programming language
+    commonly used to create interactive effects within web browsers.</p>
+  <p><a href="https://goo.gl/koeeaJ">How to enable JavaScript?</a></p>
+</noscript> <![endif]-->
+
+ +

Conclusão

+ +

The new semantic elements introduced in HTML5 bring the ability to describe the structure and the outline of a web document in a standard way. They bring a big advantage for people having HTML5 browsers and needing the structure to help them understand the page, for instance people needing the help of some assistive technology. These new semantic elements are simple to use and, with very few burdens, can be made to work also in non-HTML5 browsers. Therefore they should be used without restrictions.

+ +
{{HTML5ArticleTOC()}}
diff --git a/files/pt-pt/web/guide/index.html b/files/pt-pt/web/guide/index.html new file mode 100644 index 0000000000..8ba5341845 --- /dev/null +++ b/files/pt-pt/web/guide/index.html @@ -0,0 +1,63 @@ +--- +title: Guias do Programador +slug: Web/Guide +tags: + - API + - Guía + - Landing + - Web +translation_of: Web/Guide +--- +

Estes artigos proporcionam informação de como começar, para o ajudar a utilizar as tecnologias da Web específicas e APIs.

+ +
+
+
+
Aprender HTML; Guias e Tutoriais
+
Linguagem de Marcacao em Hiper Texto  (HTML) e a linguaguem padrao de quase todos os navegadores. Maior parte do que voce ve na janela do seu navegador e descrito, fundamentalmente, usando HTML.
+
Aprender a estilizar HTML, utilizando CSS
+
Folhas de Estilo em Cascata (CSS) e uma linguaguem baseada em folhas de estilos usada para definir a apresentacao do documento escrito com HTML.
+
Apresentacao de videos e audios
+
Nos conseguimos apresentar videos e audios na web de diversas maneiras, desde ficheiros 'estaticos' a fluxos de adaptacoes em directo. Este artigo e precebido como o ponto inicial para a exploracao de varios mecanismos de apresentacao baseados na comunicao i compatiilidade com os navegadores populares.
+
Manipulacao de videos e audios
+
A beleza da web e que voce pode combinar tecnologias para criar novos formularios. Tendo audios e videos nativos no navegador significa que nos podemos usar este fluxo de dados com tecnologias como {{htmelement('canvas')}}, WebGL ou API de Áudio da Web para modificar o audio e o video directamente, por exemplo adicionando efeitos como ressonancia/compressao ao audio, ou filtros como escala de cinza/sepia aos videos. Este artigo providencia as referencias para explicar o que voce precisa.
+
Guia do programador de eventos
+
Eventos referem se a duas coisas: o design padrao usado para manter a sincronizacao de varios incidentes que ocorrem durante a execucao da pagina web; i a nomenclatura, caracterizacao, i uso de varios i diversos tipos de ocorrencias.
+
AJAX
+
AJAX is a term that defines a group of technologies allowing web applications to make quick, incremental updates to the user interface without reloading the entire browser page. This makes the application faster and more responsive to user actions.
+
Gráficos na Web
+
Modern web sites and applications often need to present graphics of varying sophistication.
+
Guide to web APIs
+
A list of all web APIs and what they do.
+
JavaScript
+
JavaScript is the powerful scripting language used to create applications for the Web.
+
Localizations and character encodings
+
Browsers process text as Unicode internally. However, a way of representing characters in terms of bytes (character encoding) is used for transferring text over the network to the browser. The HTML specification recommends the use of the UTF-8 encoding (which can represent all of Unicode), and regardless of the encoding used requires Web content to declare that encoding.
+
Mobile web development
+
This article provides an overview of some of the main techniques needed to design web sites that work well on mobile devices. If you're looking for information on Mozilla's Firefox OS project, see the Firefox OS page. Or you might be interested in details about Firefox para Android.
+
+
+ +
+
+
Progressive web apps
+
Progressive web apps (PWAs) use modern web APIs along with traditional progressive enhancement strategy to create cross-platform web applications. These apps work everywhere and provide several features that give them the same user experience advantages as native apps. This set of guides tells you all you need to know about PWAs.
+
Optimization and performance
+
When building modern web apps and sites, it's important to make your content work quickly and efficiently. This lets it perform effectively for both powerful desktop systems and weaker handheld devices.
+
Parsing and serializing XML
+
The web platform provides different methods of parsing and serializing XML, each with its own pros and cons.
+
The Web Open Font Format (WOFF)
+
WOFF (Web Open Font Format) is a font file format that is free for anyone to use on the web.
+
Using FormData objects
+
The FormData object lets you compile a set of key/value pairs to send using XMLHttpRequest. It's primarily intended for sending form data, but can be used independently from forms in order to transmit keyed data. The transmission is in the same format that the form's submit() method would use to send the data if the form's encoding type were set to "multipart/form-data".
+
Glossary
+
Defines numerous technical terms related to the Web and Internet.
+
+
+
+ +

Consultar também

+ + -- cgit v1.2.3-54-g00ecf