Added new modifiers

`@flatten` Flattens an array with child arrays.
  [1,[2],[3,4],[5,[6,7]]] -> [1,2,3,4,5,[6,7]]
The {"deep":true} arg can be provide for deep flattening.
  [1,[2],[3,4],[5,[6,7]]] -> [1,2,3,4,5,6,7]
The original json is returned when the json is not an array.

`@join` Joins multiple objects into a single object.
  [{"first":"Tom"},{"last":"Smith"}] -> {"first","Tom","last":"Smith"}
The arg can be "true" to specify that duplicate keys should be preserved.
  [{"first":"Tom","age":37},{"age":41}] -> {"first","Tom","age":37,"age":41}
Without preserved keys:
  [{"first":"Tom","age":37},{"age":41}] -> {"first","Tom","age":41}
The original json is returned when the json is not an object.

`@valid` Ensures that the json is valid before moving on. An
empty string is returned when the json is not valid, otherwise
it returns the original json.
This commit is contained in:
tidwall 2020-02-10 11:13:30 -07:00
parent d10932a0d0
commit 0360deb6d8
4 changed files with 278 additions and 3 deletions

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@ -193,11 +193,15 @@ we'll get `children` array and reverse the order:
"children|@reverse|0" >> "Jack"
```
There are currently three built-in modifiers:
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

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@ -181,12 +181,15 @@ children.@reverse ["Jack","Alex","Sara"]
children.@reverse.0 "Jack"
```
There are currently three built-in modifiers:
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. Can be used to retrieve the root element.
- `@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

131
gjson.go
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@ -2595,6 +2595,15 @@ func execModifier(json, path string) (pathOut, res string, ok bool) {
return pathOut, res, false
}
// unwrap removes the '[]' or '{}' characters around json
func unwrap(json string) string {
json = trim(json)
if len(json) >= 2 && json[0] == '[' || json[0] == '{' {
json = json[1 : len(json)-1]
}
return json
}
// DisableModifiers will disable the modifier syntax
var DisableModifiers = false
@ -2603,6 +2612,9 @@ var modifiers = map[string]func(json, arg string) string{
"ugly": modUgly,
"reverse": modReverse,
"this": modThis,
"flatten": modFlatten,
"join": modJoin,
"valid": modValid,
}
// AddModifier binds a custom modifier command to the GJSON syntax.
@ -2691,3 +2703,122 @@ func modReverse(json, arg string) string {
}
return json
}
// @flatten an array with child arrays.
// [1,[2],[3,4],[5,[6,7]]] -> [1,2,3,4,5,[6,7]]
// The {"deep":true} arg can be provide for deep flattening.
// [1,[2],[3,4],[5,[6,7]]] -> [1,2,3,4,5,6,7]
// The original json is returned when the json is not an array.
func modFlatten(json, arg string) string {
res := Parse(json)
if !res.IsArray() {
return json
}
var deep bool
if arg != "" {
Parse(arg).ForEach(func(key, value Result) bool {
if key.String() == "deep" {
deep = value.Bool()
}
return true
})
}
var out []byte
out = append(out, '[')
var idx int
res.ForEach(func(_, value Result) bool {
if idx > 0 {
out = append(out, ',')
}
if value.IsArray() {
if deep {
out = append(out, unwrap(modFlatten(value.Raw, arg))...)
} else {
out = append(out, unwrap(value.Raw)...)
}
} else {
out = append(out, value.Raw...)
}
idx++
return true
})
out = append(out, ']')
return bytesString(out)
}
// @join multiple objects into a single object.
// [{"first":"Tom"},{"last":"Smith"}] -> {"first","Tom","last":"Smith"}
// The arg can be "true" to specify that duplicate keys should be preserved.
// [{"first":"Tom","age":37},{"age":41}] -> {"first","Tom","age":37,"age":41}
// Without preserved keys:
// [{"first":"Tom","age":37},{"age":41}] -> {"first","Tom","age":41}
// The original json is returned when the json is not an object.
func modJoin(json, arg string) string {
res := Parse(json)
if !res.IsArray() {
return json
}
var preserve bool
if arg != "" {
Parse(arg).ForEach(func(key, value Result) bool {
if key.String() == "preserve" {
preserve = value.Bool()
}
return true
})
}
var out []byte
out = append(out, '{')
if preserve {
// Preserve duplicate keys.
var idx int
res.ForEach(func(_, value Result) bool {
if !value.IsObject() {
return true
}
if idx > 0 {
out = append(out, ',')
}
out = append(out, unwrap(value.Raw)...)
idx++
return true
})
} else {
// Deduplicate keys and generate an object with stable ordering.
var keys []Result
kvals := make(map[string]Result)
res.ForEach(func(_, value Result) bool {
if !value.IsObject() {
return true
}
value.ForEach(func(key, value Result) bool {
k := key.String()
if _, ok := kvals[k]; !ok {
keys = append(keys, key)
}
kvals[k] = value
return true
})
return true
})
for i := 0; i < len(keys); i++ {
if i > 0 {
out = append(out, ',')
}
out = append(out, keys[i].Raw...)
out = append(out, ':')
out = append(out, kvals[keys[i].String()].Raw...)
}
}
out = append(out, '}')
return bytesString(out)
}
// @valid ensures that the json is valid before moving on. An empty string is
// returned when the json is not valid, otherwise it returns the original json.
func modValid(json, arg string) string {
if !Valid(json) {
return ""
}
return json
}

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@ -2025,3 +2025,140 @@ func TestChainedModifierStringArgs(t *testing.T) {
res := Get("[]", `@push:"2"|@push:"3"|@push:{"a":"b","c":["e","f"]}|@push:true|@push:10.23`)
assert(t, res.String() == `["2","3",{"a":"b","c":["e","f"]},true,10.23]`)
}
func TestFlatten(t *testing.T) {
json := `[1,[2],[3,4],[5,[6,[7]]],{"hi":"there"},8,[9]]`
assert(t, Get(json, "@flatten").String() == `[1,2,3,4,5,[6,[7]],{"hi":"there"},8,9]`)
assert(t, Get(json, `@flatten:{"deep":true}`).String() == `[1,2,3,4,5,6,7,{"hi":"there"},8,9]`)
assert(t, Get(`{"9999":1234}`, "@flatten").String() == `{"9999":1234}`)
}
func TestJoin(t *testing.T) {
assert(t, Get(`[{},{}]`, "@join").String() == `{}`)
assert(t, Get(`[{"a":1},{"b":2}]`, "@join").String() == `{"a":1,"b":2}`)
assert(t, Get(`[{"a":1,"b":1},{"b":2}]`, "@join").String() == `{"a":1,"b":2}`)
assert(t, Get(`[{"a":1,"b":1},{"b":2},5,{"c":3}]`, "@join").String() == `{"a":1,"b":2,"c":3}`)
assert(t, Get(`[{"a":1,"b":1},{"b":2},5,{"c":3}]`, `@join:{"preserve":true}`).String() == `{"a":1,"b":1,"b":2,"c":3}`)
assert(t, Get(`[{"a":1,"b":1},{"b":2},5,{"c":3}]`, `@join:{"preserve":true}.b`).String() == `1`)
assert(t, Get(`{"9999":1234}`, "@join").String() == `{"9999":1234}`)
}
func TestValid(t *testing.T) {
assert(t, Get("[{}", "@valid").Exists() == false)
assert(t, Get("[{}]", "@valid").Exists() == true)
}
// https://github.com/tidwall/gjson/issues/152
func TestJoin152(t *testing.T) {
var json = `{
"distance": 1374.0,
"validFrom": "2005-11-14",
"historical": {
"type": "Day",
"name": "last25Hours",
"summary": {
"units": {
"temperature": "C",
"wind": "m/s",
"snow": "cm",
"precipitation": "mm"
},
"days": [
{
"time": "2020-02-08",
"hours": [
{
"temperature": {
"min": -2.0,
"max": -1.6,
"value": -1.6
},
"wind": {},
"precipitation": {},
"humidity": {
"value": 92.0
},
"snow": {
"depth": 49.0
},
"time": "2020-02-08T16:00:00+01:00"
},
{
"temperature": {
"min": -1.7,
"max": -1.3,
"value": -1.3
},
"wind": {},
"precipitation": {},
"humidity": {
"value": 92.0
},
"snow": {
"depth": 49.0
},
"time": "2020-02-08T17:00:00+01:00"
},
{
"temperature": {
"min": -1.3,
"max": -0.9,
"value": -1.2
},
"wind": {},
"precipitation": {},
"humidity": {
"value": 91.0
},
"snow": {
"depth": 49.0
},
"time": "2020-02-08T18:00:00+01:00"
}
]
},
{
"time": "2020-02-09",
"hours": [
{
"temperature": {
"min": -1.7,
"max": -0.9,
"value": -1.5
},
"wind": {},
"precipitation": {},
"humidity": {
"value": 91.0
},
"snow": {
"depth": 49.0
},
"time": "2020-02-09T00:00:00+01:00"
},
{
"temperature": {
"min": -1.5,
"max": 0.9,
"value": 0.2
},
"wind": {},
"precipitation": {},
"humidity": {
"value": 67.0
},
"snow": {
"depth": 49.0
},
"time": "2020-02-09T01:00:00+01:00"
}
]
}
]
}
}
}`
res := Get(json, "historical.summary.days.#.hours|@flatten|#.humidity.value")
assert(t, res.Raw == `[92.0,92.0,91.0,91.0,67.0]`)
}