jsonquery is XPath query package for JSON document depended on xpath package, writing in go.
jsonquery helps you easy to extract any data from JSON using XPath query without using pre-defined object structure to unmarshal in go, saving your time.
go get github.com/antchfx/jsonquery
The below code may be help your understand what it does. We don't need pre-defined structure or using regexp to extract some data in JSON file, gets any data is easy and fast in jsonquery now.
Using an xpath like syntax to access specific fields of a json structure.
// https://go.dev/play/p/vqoD_jWryKY
package main
import (
"fmt"
"strings"
"github.com/antchfx/jsonquery"
)
func main() {
s := `{
"person":{
"name":"John",
"age":31,
"female":false,
"city":null,
"hobbies":[
"coding",
"eating",
"football"
]
}
}`
doc, err := jsonquery.Parse(strings.NewReader(s))
if err != nil {
panic(err)
}
// xpath query
age := jsonquery.FindOne(doc, "age")
// or
age = jsonquery.FindOne(doc, "person/age")
fmt.Printf("%#v[%T]\n", age.Value(), age.Value()) // prints 31[float64]
hobbies := jsonquery.FindOne(doc, "//hobbies")
fmt.Printf("%#v\n", hobbies.Value()) // prints []interface {}{"coding", "eating", "football"}
firstHobby := jsonquery.FindOne(doc, "//hobbies/*[1]")
fmt.Printf("%#v\n", firstHobby.Value()) // "coding"
}Iterating over a json structure.
// https://go.dev/play/p/vwXQKTCLdVK
package main
import (
"fmt"
"strings"
"github.com/antchfx/jsonquery"
)
func main() {
s := `{
"name":"John",
"age":31,
"female":false,
"city":null
}`
doc, err := jsonquery.Parse(strings.NewReader(s))
if err != nil {
panic(err)
}
// iterate all json objects from child ndoes.
for _, n := range doc.ChildNodes() {
fmt.Printf("%s: %v[%T]\n", n.Data, n.Value(), n.Value())
}
}Output:
name: John[string]
age: 31[float64]
female: false[bool]
city: <nil>[<nil>]
The default Json types and Go types are:
| JSON | jsonquery(go) |
|---|---|
| object | interface{} |
| string | string |
| number | float64 |
| boolean | bool |
| array | []interface{} |
| null | nil |
For more information about JSON & Go see the https://go.dev/blog/json
doc, err := jsonquery.LoadURL("http://www.example.com/feed?json")s :=`{
"name":"John",
"age":31,
"city":"New York"
}`
doc, err := jsonquery.Parse(strings.NewReader(s))f, err := os.Open("./books.json")
doc, err := jsonquery.Parse(f)s := `[1,2,3,4,5,6]`
doc, _ := jsonquery.Parse(strings.NewReader(s))
list := jsonquery.Find(doc, "*")
for _, n := range list {
fmt.Print(n.Value().(float64))
}// Output: 1,2,3,4,5,6
s := `[{"name":"John", "age":31, "female":false, "city":null}]`
doc, _ := jsonquery.Parse(strings.NewReader(s))
fmt.Println(doc.OutputXML())n := jsonquery.FindOne(doc,"//a")list := jsonquery.Find(doc,"//a")n := jsonquery.QuerySelector(doc, xpath.MustCompile("//a"))list :=jsonquery.QuerySelectorAll(doc, xpath.MustCompile("//a"))n, err := jsonquery.Query(doc, "*")list, err := jsonquery.QueryAll(doc, "*")-
Query()will return an error if give xpath query expr is not valid. -
FindOnewill panic error and interrupt your program if give xpath query expr is not valid.
Convert current JSON object to XML format.
{
"store": {
"book": [
{
"id": 1,
"category": "reference",
"author": "Nigel Rees",
"title": "Sayings of the Century",
"price": 8.95
},
{
"id": 2,
"category": "fiction",
"author": "Evelyn Waugh",
"title": "Sword of Honour",
"price": 12.99
},
{
"id": 3,
"category": "fiction",
"author": "Herman Melville",
"title": "Moby Dick",
"isbn": "0-553-21311-3",
"price": 8.99
},
{
"id": 4,
"category": "fiction",
"author": "J. R. R. Tolkien",
"title": "The Lord of the Rings",
"isbn": "0-395-19395-8",
"price": 22.99
}
],
"bicycle": {
"color": "red",
"price": 19.95
}
},
"expensive": 10
}doc, err := jsonquery.Parse(strings.NewReader(s))
if err != nil {
panic(err)
}
fmt.Println(doc.OutputXML())Output the below XML:
<?xml version="1.0" encoding="utf-8"?>
<root>
<expensive>10</expensive>
<store>
<bicycle>
<color>red</color>
<price>19.95</price>
</bicycle>
<book>
<author>Nigel Rees</author>
<category>reference</category>
<id>1</id>
<price>8.95</price>
<title>Sayings of the Century</title>
</book>
<book>
<author>Evelyn Waugh</author>
<category>fiction</category>
<id>2</id>
<price>12.99</price>
<title>Sword of Honour</title>
</book>
<book>
<author>Herman Melville</author>
<category>fiction</category>
<id>3</id>
<isbn>0-553-21311-3</isbn>
<price>8.99</price>
<title>Moby Dick</title>
</book>
<book>
<author>J. R. R. Tolkien</author>
<category>fiction</category>
<id>4</id>
<isbn>0-395-19395-8</isbn>
<price>22.99</price>
<title>The Lord of the Rings</title>
</book>
</store>
</root>| Query | Matched | Native Value Types | Native Values |
|---|---|---|---|
//book |
1 | []interface{} | {"book": [{"id":1,... }, {"id":2,... }, {"id":3,... }, {"id":4,... }]} |
//book/* |
4 | [map[string]interface{}] | {"id":1,... }, {"id":2,... }, {"id":3,... }, {"id":4,... } |
//*[price<12.99] |
2 | [map[string]interface{}] | {"id":1,...}, {"id":3,...} |
//book/*/author |
4 | []string | {"author": "Nigel Rees"}, {"author": "Evelyn Waugh"}, {"author": "Herman Melville"}, {"author": "J. R. R. Tolkien"} |
//book/*[last()] |
1 | map[string]interface {} | {"id":4,...} |
//book/*[2] |
1 | map[string]interface{} | {"id":2,...} |
//*[isbn] |
2 | [map[string]interface{}] | {"id":3,"isbn":"0-553-21311-3",...},{"id":4,"isbn":"0-395-19395-8",...} |
//*[isbn='0-553-21311-3'] |
1 | map[string]interface{} | {"id":3,"isbn":"0-553-21311-3",...} |
//bicycle |
1 | map[string]interface {} | {"bicycle":{"color":...,}} |
//bicycle/color[text()='red'] |
1 | map[string]interface {} | {"color":"red"} |
//*/category[contains(.,'refer')] |
1 | string | {"category": "reference"} |
//price[.=22.99] |
1 | float64 | {"price": 22.99} |
//expensive/text() |
1 | string | 10 |
For more supports XPath feature and function see https://github.com/antchfx/xpath