Compare commits
No commits in common. "master" and "v1.0.5" have entirely different histories.
176
README.md
176
README.md
|
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@ -5,17 +5,15 @@
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<br>
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<a href="https://travis-ci.org/tidwall/gjson"><img src="https://img.shields.io/travis/tidwall/gjson.svg?style=flat-square" alt="Build Status"></a>
|
||||
<a href="https://godoc.org/github.com/tidwall/gjson"><img src="https://img.shields.io/badge/api-reference-blue.svg?style=flat-square" alt="GoDoc"></a>
|
||||
<a href="http://tidwall.com/gjson-play"><img src="https://img.shields.io/badge/%F0%9F%8F%90-playground-9900cc.svg?style=flat-square" alt="GJSON Playground"></a>
|
||||
<a href="http://tidwall.com/gjson-play"><img src="https://img.shields.io/badge/play-ground-orange.svg?style=flat-square" alt="GJSON Playground"></a>
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</p>
|
||||
|
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|
||||
|
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<p align="center">get json values quickly</a></p>
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<p align="center">get a json value quickly</a></p>
|
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|
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GJSON is a Go package that provides a [fast](#performance) and [simple](#get-a-value) way to get values from a json document.
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It has features such as [one line retrieval](#get-a-value), [dot notation paths](#path-syntax), [iteration](#iterate-through-an-object-or-array), and [parsing json lines](#json-lines).
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||||
Also check out [SJSON](https://github.com/tidwall/sjson) for modifying json, and the [JJ](https://github.com/tidwall/jj) command line tool.
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It has features such as [one line retrieval](#get-a-value), [dot notation paths](#path-syntax), [iteration](#iterate-through-an-object-or-array).
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|
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Getting Started
|
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===============
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|
|
@ -31,7 +29,7 @@ $ go get -u github.com/tidwall/gjson
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This will retrieve the library.
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|
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## Get a value
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Get searches json for the specified path. A path is in dot syntax, such as "name.last" or "age". When the value is found it's returned immediately.
|
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Get searches json for the specified path. A path is in dot syntax, such as "name.last" or "age". This function expects that the json is well-formed. Bad json will not panic, but it may return back unexpected results. When the value is found it's returned immediately.
|
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|
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```go
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package main
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|
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@ -55,9 +53,6 @@ Prichard
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|
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## Path Syntax
|
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|
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Below is a quick overview of the path syntax, for more complete information please
|
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check out [GJSON Syntax](SYNTAX.md).
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|
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A path is a series of keys separated by a dot.
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A key may contain special wildcard characters '\*' and '?'.
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To access an array value use the index as the key.
|
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|
|
@ -71,9 +66,9 @@ The dot and wildcard characters can be escaped with '\\'.
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"children": ["Sara","Alex","Jack"],
|
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"fav.movie": "Deer Hunter",
|
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"friends": [
|
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{"first": "Dale", "last": "Murphy", "age": 44, "nets": ["ig", "fb", "tw"]},
|
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{"first": "Roger", "last": "Craig", "age": 68, "nets": ["fb", "tw"]},
|
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{"first": "Jane", "last": "Murphy", "age": 47, "nets": ["ig", "tw"]}
|
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{"first": "Dale", "last": "Murphy", "age": 44},
|
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{"first": "Roger", "last": "Craig", "age": 68},
|
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{"first": "Jane", "last": "Murphy", "age": 47}
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]
|
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}
|
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```
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|
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@ -90,25 +85,16 @@ The dot and wildcard characters can be escaped with '\\'.
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"friends.1.last" >> "Craig"
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```
|
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|
||||
You can also query an array for the first match by using `#(...)`, or find all
|
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matches with `#(...)#`. Queries support the `==`, `!=`, `<`, `<=`, `>`, `>=`
|
||||
comparison operators and the simple pattern matching `%` (like) and `!%`
|
||||
(not like) operators.
|
||||
You can also query an array for the first match by using `#[...]`, or find all matches with `#[...]#`.
|
||||
Queries support the `==`, `!=`, `<`, `<=`, `>`, `>=` comparison operators and the simple pattern matching `%` operator.
|
||||
|
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```
|
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friends.#(last=="Murphy").first >> "Dale"
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friends.#(last=="Murphy")#.first >> ["Dale","Jane"]
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friends.#(age>45)#.last >> ["Craig","Murphy"]
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friends.#(first%"D*").last >> "Murphy"
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friends.#(first!%"D*").last >> "Craig"
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friends.#(nets.#(=="fb"))#.first >> ["Dale","Roger"]
|
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friends.#[last=="Murphy"].first >> "Dale"
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friends.#[last=="Murphy"]#.first >> ["Dale","Jane"]
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friends.#[age>45]#.last >> ["Craig","Murphy"]
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friends.#[first%"D*"].last >> "Murphy"
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```
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|
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*Please note that prior to v1.3.0, queries used the `#[...]` brackets. This was
|
||||
changed in v1.3.0 as to avoid confusion with the new
|
||||
[multipath](SYNTAX.md#multipaths) syntax. For backwards compatibility,
|
||||
`#[...]` will continue to work until the next major release.*
|
||||
|
||||
## Result Type
|
||||
|
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GJSON supports the json types `string`, `number`, `bool`, and `null`.
|
||||
|
|
@ -166,127 +152,6 @@ array >> []interface{}
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|||
object >> map[string]interface{}
|
||||
```
|
||||
|
||||
### 64-bit integers
|
||||
|
||||
The `result.Int()` and `result.Uint()` calls are capable of reading all 64 bits, allowing for large JSON integers.
|
||||
|
||||
```go
|
||||
result.Int() int64 // -9223372036854775808 to 9223372036854775807
|
||||
result.Uint() int64 // 0 to 18446744073709551615
|
||||
```
|
||||
|
||||
## Modifiers and path chaining
|
||||
|
||||
New in version 1.2 is support for modifier functions and path chaining.
|
||||
|
||||
A modifier is a path component that performs custom processing on the
|
||||
json.
|
||||
|
||||
Multiple paths can be "chained" together using the pipe character.
|
||||
This is useful for getting results from a modified query.
|
||||
|
||||
For example, using the built-in `@reverse` modifier on the above json document,
|
||||
we'll get `children` array and reverse the order:
|
||||
|
||||
```
|
||||
"children|@reverse" >> ["Jack","Alex","Sara"]
|
||||
"children|@reverse|0" >> "Jack"
|
||||
```
|
||||
|
||||
There are currently the following built-in modifiers:
|
||||
|
||||
- `@reverse`: Reverse an array or the members of an object.
|
||||
- `@ugly`: Remove all whitespace from a json document.
|
||||
- `@pretty`: Make the json document more human readable.
|
||||
- `@this`: Returns the current element. It can be used to retrieve the root element.
|
||||
- `@valid`: Ensure the json document is valid.
|
||||
- `@flatten`: Flattens an array.
|
||||
- `@join`: Joins multiple objects into a single object.
|
||||
|
||||
### Modifier arguments
|
||||
|
||||
A modifier may accept an optional argument. The argument can be a valid JSON
|
||||
document or just characters.
|
||||
|
||||
For example, the `@pretty` modifier takes a json object as its argument.
|
||||
|
||||
```
|
||||
@pretty:{"sortKeys":true}
|
||||
```
|
||||
|
||||
Which makes the json pretty and orders all of its keys.
|
||||
|
||||
```json
|
||||
{
|
||||
"age":37,
|
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"children": ["Sara","Alex","Jack"],
|
||||
"fav.movie": "Deer Hunter",
|
||||
"friends": [
|
||||
{"age": 44, "first": "Dale", "last": "Murphy"},
|
||||
{"age": 68, "first": "Roger", "last": "Craig"},
|
||||
{"age": 47, "first": "Jane", "last": "Murphy"}
|
||||
],
|
||||
"name": {"first": "Tom", "last": "Anderson"}
|
||||
}
|
||||
```
|
||||
|
||||
*The full list of `@pretty` options are `sortKeys`, `indent`, `prefix`, and `width`.
|
||||
Please see [Pretty Options](https://github.com/tidwall/pretty#customized-output) for more information.*
|
||||
|
||||
### Custom modifiers
|
||||
|
||||
You can also add custom modifiers.
|
||||
|
||||
For example, here we create a modifier that makes the entire json document upper
|
||||
or lower case.
|
||||
|
||||
```go
|
||||
gjson.AddModifier("case", func(json, arg string) string {
|
||||
if arg == "upper" {
|
||||
return strings.ToUpper(json)
|
||||
}
|
||||
if arg == "lower" {
|
||||
return strings.ToLower(json)
|
||||
}
|
||||
return json
|
||||
})
|
||||
```
|
||||
|
||||
```
|
||||
"children|@case:upper" >> ["SARA","ALEX","JACK"]
|
||||
"children|@case:lower|@reverse" >> ["jack","alex","sara"]
|
||||
```
|
||||
|
||||
## JSON Lines
|
||||
|
||||
There's support for [JSON Lines](http://jsonlines.org/) using the `..` prefix, which treats a multilined document as an array.
|
||||
|
||||
For example:
|
||||
|
||||
```
|
||||
{"name": "Gilbert", "age": 61}
|
||||
{"name": "Alexa", "age": 34}
|
||||
{"name": "May", "age": 57}
|
||||
{"name": "Deloise", "age": 44}
|
||||
```
|
||||
|
||||
```
|
||||
..# >> 4
|
||||
..1 >> {"name": "Alexa", "age": 34}
|
||||
..3 >> {"name": "Deloise", "age": 44}
|
||||
..#.name >> ["Gilbert","Alexa","May","Deloise"]
|
||||
..#(name="May").age >> 57
|
||||
```
|
||||
|
||||
The `ForEachLines` function will iterate through JSON lines.
|
||||
|
||||
```go
|
||||
gjson.ForEachLine(json, func(line gjson.Result) bool{
|
||||
println(line.String())
|
||||
return true
|
||||
})
|
||||
```
|
||||
|
||||
## Get nested array values
|
||||
|
||||
Suppose you want all the last names from the following json:
|
||||
|
|
@ -320,7 +185,7 @@ for _, name := range result.Array() {
|
|||
You can also query an object inside an array:
|
||||
|
||||
```go
|
||||
name := gjson.Get(json, `programmers.#(lastName="Hunter").firstName`)
|
||||
name := gjson.Get(json, `programmers.#[lastName="Hunter"].firstName`)
|
||||
println(name.String()) // prints "Elliotte"
|
||||
```
|
||||
|
||||
|
|
@ -369,19 +234,6 @@ if gjson.Get(json, "name.last").Exists() {
|
|||
}
|
||||
```
|
||||
|
||||
## Validate JSON
|
||||
|
||||
The `Get*` and `Parse*` functions expects that the json is well-formed. Bad json will not panic, but it may return back unexpected results.
|
||||
|
||||
If you are consuming JSON from an unpredictable source then you may want to validate prior to using GJSON.
|
||||
|
||||
```go
|
||||
if !gjson.Valid(json) {
|
||||
return errors.New("invalid json")
|
||||
}
|
||||
value := gjson.Get(json, "name.last")
|
||||
```
|
||||
|
||||
## Unmarshal to a map
|
||||
|
||||
To unmarshal to a `map[string]interface{}`:
|
||||
|
|
|
|||
277
SYNTAX.md
277
SYNTAX.md
|
|
@ -1,277 +0,0 @@
|
|||
# GJSON Path Syntax
|
||||
|
||||
A GJSON Path is a text string syntax that describes a search pattern for quickly retreiving values from a JSON payload.
|
||||
|
||||
This document is designed to explain the structure of a GJSON Path through examples.
|
||||
|
||||
- [Path structure](#path-structure)
|
||||
- [Basic](#basic)
|
||||
- [Wildcards](#wildcards)
|
||||
- [Escape Character](#escape-character)
|
||||
- [Arrays](#arrays)
|
||||
- [Queries](#queries)
|
||||
- [Dot vs Pipe](#dot-vs-pipe)
|
||||
- [Modifiers](#modifiers)
|
||||
- [Multipaths](#multipaths)
|
||||
|
||||
The definitive implemenation is [github.com/tidwall/gjson](https://github.com/tidwall/gjson).
|
||||
Use the [GJSON Playground](https://gjson.dev) to experiment with the syntax online.
|
||||
|
||||
|
||||
## Path structure
|
||||
|
||||
A GJSON Path is intended to be easily expressed as a series of components seperated by a `.` character.
|
||||
|
||||
Along with `.` character, there are a few more that have special meaning, including `|`, `#`, `@`, `\`, `*`, and `?`.
|
||||
|
||||
## Example
|
||||
|
||||
Given this JSON
|
||||
|
||||
```json
|
||||
{
|
||||
"name": {"first": "Tom", "last": "Anderson"},
|
||||
"age":37,
|
||||
"children": ["Sara","Alex","Jack"],
|
||||
"fav.movie": "Deer Hunter",
|
||||
"friends": [
|
||||
{"first": "Dale", "last": "Murphy", "age": 44, "nets": ["ig", "fb", "tw"]},
|
||||
{"first": "Roger", "last": "Craig", "age": 68, "nets": ["fb", "tw"]},
|
||||
{"first": "Jane", "last": "Murphy", "age": 47, "nets": ["ig", "tw"]}
|
||||
]
|
||||
}
|
||||
```
|
||||
|
||||
The following GJSON Paths evaluate to the accompanying values.
|
||||
|
||||
### Basic
|
||||
|
||||
In many cases you'll just want to retreive values by object name or array index.
|
||||
|
||||
```go
|
||||
name.last "Anderson"
|
||||
name.first "Tom"
|
||||
age 37
|
||||
children ["Sara","Alex","Jack"]
|
||||
children.0 "Sara"
|
||||
children.1 "Alex"
|
||||
friends.1 {"first": "Roger", "last": "Craig", "age": 68}
|
||||
friends.1.first "Roger"
|
||||
```
|
||||
|
||||
### Wildcards
|
||||
|
||||
A key may contain the special wildcard characters `*` and `?`.
|
||||
The `*` will match on any zero+ characters, and `?` matches on any one character.
|
||||
|
||||
```go
|
||||
child*.2 "Jack"
|
||||
c?ildren.0 "Sara"
|
||||
```
|
||||
|
||||
### Escape character
|
||||
|
||||
Special purpose characters, such as `.`, `*`, and `?` can be escaped with `\`.
|
||||
|
||||
```go
|
||||
fav\.movie "Deer Hunter"
|
||||
```
|
||||
|
||||
You'll also need to make sure that the `\` character is correctly escaped when hardcoding a path in source code.
|
||||
|
||||
```go
|
||||
res := gjson.Get(json, "fav\\.movie") // must escape the slash
|
||||
res := gjson.Get(json, `fav\.movie`) // no need to escape the slash
|
||||
|
||||
```
|
||||
|
||||
### Arrays
|
||||
|
||||
The `#` character allows for digging into JSON Arrays.
|
||||
|
||||
To get the length of an array you'll just use the `#` all by itself.
|
||||
|
||||
```go
|
||||
friends.# 3
|
||||
friends.#.age [44,68,47]
|
||||
```
|
||||
|
||||
### Queries
|
||||
|
||||
You can also query an array for the first match by using `#(...)`, or find all matches with `#(...)#`.
|
||||
Queries support the `==`, `!=`, `<`, `<=`, `>`, `>=` comparison operators,
|
||||
and the simple pattern matching `%` (like) and `!%` (not like) operators.
|
||||
|
||||
```go
|
||||
friends.#(last=="Murphy").first "Dale"
|
||||
friends.#(last=="Murphy")#.first ["Dale","Jane"]
|
||||
friends.#(age>45)#.last ["Craig","Murphy"]
|
||||
friends.#(first%"D*").last "Murphy"
|
||||
friends.#(first!%"D*").last "Craig"
|
||||
```
|
||||
|
||||
To query for a non-object value in an array, you can forgo the string to the right of the operator.
|
||||
|
||||
```go
|
||||
children.#(!%"*a*") "Alex"
|
||||
children.#(%"*a*")# ["Sara","Jack"]
|
||||
```
|
||||
|
||||
Nested queries are allowed.
|
||||
|
||||
```go
|
||||
friends.#(nets.#(=="fb"))#.first >> ["Dale","Roger"]
|
||||
```
|
||||
|
||||
*Please note that prior to v1.3.0, queries used the `#[...]` brackets. This was
|
||||
changed in v1.3.0 as to avoid confusion with the new [multipath](#multipaths)
|
||||
syntax. For backwards compatibility, `#[...]` will continue to work until the
|
||||
next major release.*
|
||||
|
||||
### Dot vs Pipe
|
||||
|
||||
The `.` is standard separator, but it's also possible to use a `|`.
|
||||
In most cases they both end up returning the same results.
|
||||
The cases where`|` differs from `.` is when it's used after the `#` for [Arrays](#arrays) and [Queries](#queries).
|
||||
|
||||
Here are some examples
|
||||
|
||||
```go
|
||||
friends.0.first "Dale"
|
||||
friends|0.first "Dale"
|
||||
friends.0|first "Dale"
|
||||
friends|0|first "Dale"
|
||||
friends|# 3
|
||||
friends.# 3
|
||||
friends.#(last="Murphy")# [{"first": "Dale", "last": "Murphy", "age": 44},{"first": "Jane", "last": "Murphy", "age": 47}]
|
||||
friends.#(last="Murphy")#.first ["Dale","Jane"]
|
||||
friends.#(last="Murphy")#|first <non-existent>
|
||||
friends.#(last="Murphy")#.0 []
|
||||
friends.#(last="Murphy")#|0 {"first": "Dale", "last": "Murphy", "age": 44}
|
||||
friends.#(last="Murphy")#.# []
|
||||
friends.#(last="Murphy")#|# 2
|
||||
```
|
||||
|
||||
Let's break down a few of these.
|
||||
|
||||
The path `friends.#(last="Murphy")#` all by itself results in
|
||||
|
||||
```json
|
||||
[{"first": "Dale", "last": "Murphy", "age": 44},{"first": "Jane", "last": "Murphy", "age": 47}]
|
||||
```
|
||||
|
||||
The `.first` suffix will process the `first` path on each array element *before* returning the results. Which becomes
|
||||
|
||||
```json
|
||||
["Dale","Jane"]
|
||||
```
|
||||
|
||||
But the `|first` suffix actually processes the `first` path *after* the previous result.
|
||||
Since the previous result is an array, not an object, it's not possible to process
|
||||
because `first` does not exist.
|
||||
|
||||
Yet, `|0` suffix returns
|
||||
|
||||
```json
|
||||
{"first": "Dale", "last": "Murphy", "age": 44}
|
||||
```
|
||||
|
||||
Because `0` is the first index of the previous result.
|
||||
|
||||
### Modifiers
|
||||
|
||||
A modifier is a path component that performs custom processing on the JSON.
|
||||
|
||||
For example, using the built-in `@reverse` modifier on the above JSON payload will reverse the `children` array:
|
||||
|
||||
```go
|
||||
children.@reverse ["Jack","Alex","Sara"]
|
||||
children.@reverse.0 "Jack"
|
||||
```
|
||||
|
||||
There are currently the following built-in modifiers:
|
||||
|
||||
- `@reverse`: Reverse an array or the members of an object.
|
||||
- `@ugly`: Remove all whitespace from JSON.
|
||||
- `@pretty`: Make the JSON more human readable.
|
||||
- `@this`: Returns the current element. It can be used to retrieve the root element.
|
||||
- `@valid`: Ensure the json document is valid.
|
||||
- `@flatten`: Flattens an array.
|
||||
- `@join`: Joins multiple objects into a single object.
|
||||
|
||||
#### Modifier arguments
|
||||
|
||||
A modifier may accept an optional argument. The argument can be a valid JSON payload or just characters.
|
||||
|
||||
For example, the `@pretty` modifier takes a json object as its argument.
|
||||
|
||||
```
|
||||
@pretty:{"sortKeys":true}
|
||||
```
|
||||
|
||||
Which makes the json pretty and orders all of its keys.
|
||||
|
||||
```json
|
||||
{
|
||||
"age":37,
|
||||
"children": ["Sara","Alex","Jack"],
|
||||
"fav.movie": "Deer Hunter",
|
||||
"friends": [
|
||||
{"age": 44, "first": "Dale", "last": "Murphy"},
|
||||
{"age": 68, "first": "Roger", "last": "Craig"},
|
||||
{"age": 47, "first": "Jane", "last": "Murphy"}
|
||||
],
|
||||
"name": {"first": "Tom", "last": "Anderson"}
|
||||
}
|
||||
```
|
||||
|
||||
*The full list of `@pretty` options are `sortKeys`, `indent`, `prefix`, and `width`.
|
||||
Please see [Pretty Options](https://github.com/tidwall/pretty#customized-output) for more information.*
|
||||
|
||||
#### Custom modifiers
|
||||
|
||||
You can also add custom modifiers.
|
||||
|
||||
For example, here we create a modifier which makes the entire JSON payload upper or lower case.
|
||||
|
||||
```go
|
||||
gjson.AddModifier("case", func(json, arg string) string {
|
||||
if arg == "upper" {
|
||||
return strings.ToUpper(json)
|
||||
}
|
||||
if arg == "lower" {
|
||||
return strings.ToLower(json)
|
||||
}
|
||||
return json
|
||||
})
|
||||
"children.@case:upper" ["SARA","ALEX","JACK"]
|
||||
"children.@case:lower.@reverse" ["jack","alex","sara"]
|
||||
```
|
||||
|
||||
### Multipaths
|
||||
|
||||
Starting with v1.3.0, GJSON added the ability to join multiple paths together
|
||||
to form new documents. Wrapping comma-separated paths between `{...}` or
|
||||
`[...]` will result in a new array or object, respectively.
|
||||
|
||||
For example, using the given multipath
|
||||
|
||||
```
|
||||
{name.first,age,"the_murphys":friends.#(last="Murphy")#.first}
|
||||
```
|
||||
|
||||
Here we selected the first name, age, and the first name for friends with the
|
||||
last name "Murphy".
|
||||
|
||||
You'll notice that an optional key can be provided, in this case
|
||||
"the_murphys", to force assign a key to a value. Otherwise, the name of the
|
||||
actual field will be used, in this case "first". If a name cannot be
|
||||
determined, then "_" is used.
|
||||
|
||||
This results in
|
||||
|
||||
```
|
||||
{"first":"Tom","age":37,"the_murphys":["Dale","Jane"]}
|
||||
```
|
||||
|
||||
|
||||
1149
gjson_test.go
1149
gjson_test.go
File diff suppressed because it is too large
Load Diff
8
go.mod
8
go.mod
|
|
@ -1,8 +0,0 @@
|
|||
module github.com/tidwall/gjson
|
||||
|
||||
go 1.12
|
||||
|
||||
require (
|
||||
github.com/tidwall/match v1.0.1
|
||||
github.com/tidwall/pretty v1.0.0
|
||||
)
|
||||
4
go.sum
4
go.sum
|
|
@ -1,4 +0,0 @@
|
|||
github.com/tidwall/match v1.0.1 h1:PnKP62LPNxHKTwvHHZZzdOAOCtsJTjo6dZLCwpKm5xc=
|
||||
github.com/tidwall/match v1.0.1/go.mod h1:LujAq0jyVjBy028G1WhWfIzbpQfMO8bBZ6Tyb0+pL9E=
|
||||
github.com/tidwall/pretty v1.0.0 h1:HsD+QiTn7sK6flMKIvNmpqz1qrpP3Ps6jOKIKMooyg4=
|
||||
github.com/tidwall/pretty v1.0.0/go.mod h1:XNkn88O1ChpSDQmQeStsy+sBenx6DDtFZJxhVysOjyk=
|
||||
Loading…
Reference in New Issue
Block a user