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[](https://godoc.org/github.com/exponent-io/jsonpath)
[](https://travis-ci.org/exponent-io/jsonpath)
# jsonpath
This package extends the [json.Decoder](https://golang.org/pkg/encoding/json/#Decoder) to support navigating a stream of JSON tokens. You should be able to use this extended Decoder places where a json.Decoder would have been used.
This Decoder has the following enhancements...
* The [Scan](https://godoc.org/github.com/exponent-io/jsonpath/#Decoder.Scan) method supports scanning a JSON stream while extracting particular values along the way using [PathActions](https://godoc.org/github.com/exponent-io/jsonpath#PathActions).
* The [SeekTo](https://godoc.org/github.com/exponent-io/jsonpath#Decoder.SeekTo) method supports seeking forward in a JSON token stream to a particular path.
* The [Path](https://godoc.org/github.com/exponent-io/jsonpath#Decoder.Path) method returns the path of the most recently parsed token.
* The [Token](https://godoc.org/github.com/exponent-io/jsonpath#Decoder.Token) method has been modified to distinguish between strings that are object keys and strings that are values. Object key strings are returned as the [KeyString](https://godoc.org/github.com/exponent-io/jsonpath#KeyString) type rather than a native string.
## Installation
go get -u github.com/exponent-io/jsonpath
## Example Usage
#### SeekTo
```go
import "github.com/exponent-io/jsonpath"
var j = []byte(`[
{"Space": "YCbCr", "Point": {"Y": 255, "Cb": 0, "Cr": -10}},
{"Space": "RGB", "Point": {"R": 98, "G": 218, "B": 255}}
]`)
w := json.NewDecoder(bytes.NewReader(j))
var v interface{}
w.SeekTo(1, "Point", "G")
w.Decode(&v) // v is 218
```
#### Scan with PathActions
```go
var j = []byte(`{"colors":[
{"Space": "YCbCr", "Point": {"Y": 255, "Cb": 0, "Cr": -10, "A": 58}},
{"Space": "RGB", "Point": {"R": 98, "G": 218, "B": 255, "A": 231}}
]}`)
var actions PathActions
// Extract the value at Point.A
actions.Add(func(d *Decoder) error {
var alpha int
err := d.Decode(&alpha)
fmt.Printf("Alpha: %v\n", alpha)
return err
}, "Point", "A")
w := NewDecoder(bytes.NewReader(j))
w.SeekTo("colors", 0)
var ok = true
var err error
for ok {
ok, err = w.Scan(&actions)
if err != nil && err != io.EOF {
panic(err)
}
}
```
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