README
¶
JSONExtract
Package jsonextract is a library for extracting JSON from a given source, such as string, bytes, file, and io.Reader, providing methods for editing and evaluating json values. One of the cases to use this library is to extract all json strings in a scraped HTML page
Installation
JSONExtract require Go v1.14 or higher
$ GO111MODULE go get github.com/tamboto2000/jsonextract/v3
Sources
You can extract jsons from string, []byte, file, and an io.Reader
// from string
jsons, err := jsonextract.FromString(str)
// from []byte
jsons, err := jsonextract.FromBytes(byts)
// from file path
jsons, err := jsonextract.FromFile(path)
// from io.Reader
jsons, err := jsonextract.FromReader(reader)
JSON Kinds
There's 7 different kinds of JSON:
- Object
- Array
- String
- Integer
- Float
- Boolean
- Null
You can get JSON kind by calling JSON.Kind()
jsons, err := jsonextract.FromBytes(byts)
if err != nil {
panic(err.Error())
}
for _, json := range jsons {
// string
if json.Kind() == jsonextract.String {
// print string value
fmt.Println(json.String())
}
// int
if json.Kind() == jsonextract.Integer {
// print integer value, returned integer value is int64
fmt.Println(json.Integer())
}
// float
if json.Kind() == jsonextract.Float {
// print float value, returned float is float64
fmt.Println(json.Float())
}
// and so on...
}
Getter methods, such as JSON.String(), JSON.Integer(), JSON.Float(), etc., will panic if JSON kind did not match the getter methods, for example, when trying to get string value from JSON with kind of Integer. JSON with kind of Null didn't have getter method
Modifying Value
Value inside JSON can be modified by setter methods, such as JSON.SetStr(), JSON.SetInt(), etc.
// integer
if json.Kind() == jsonextract.Integer {
json.EditInt(23)
}
// string
if json.Kind() == jsonextract.String {
json.EditStr("Hello World!")
}
// and so on...
Setter methods will panic if JSON kind did not match with setter method, for example, trying to call JSON.SetInt() to JSON with kind of String. JSON with kind of Null didn't have setter method
JSON Object
Json object represented as JSON with kind of Object. For adding a new value, call JSON.AddField() with param key as json field name, and val for the value
json.AddField("name", "Franklin Collin Tamboto")
json.AddField("email", "tamboto2000@gmail.com")
json.AddField("id", 1)
i := 1
json.AddField("id", &i)
json.AddField("qty", int32(23))
json.AddField("userId", uint(2))
json.AddField("height", float32(3.2))
Just like package encoding/json, map and struct will be marshaled as json object. map keys need to be type string or an integer type, otherwise panic will occur
type User struct {
ID int `json:"id"`
Name string `json:"name"`
// field name will be used as json field name if json tag is not present,
// so this field will be marshaled as "Email":"value"
Email string
}
// add struct
json.AddField("user", User{
ID: 1,
Name: "Franklin Collin Tamboto",
Email: "tamboto2000@gmail.com",
})
// add map
json.AddField("item", map[interface{}]interface{}{
"Name": "ROG Zephyrus M",
"Qty": 23,
123: 456,
})
// add value with int as key
json.AddField(123, 456)
// add value with uint8 as key
json.AddField(uint8(432), "123")
To delete an item from object, call JSON.DeleteField() with param key as json field name for deletion. key must be string or an integer type, otherwise panic will occur. JSON.DeleteField() return true if item is exist, otherwise false will returned
// delete with string key
if json.DeleteField("user") {
fmt.Println("item deleted")
} else {
fmt.Println("item not exist")
}
// delete with integer key
if json.DeleteField(int32(123)) {
fmt.Println("item deleted")
} else {
fmt.Println("item not exist")
}
To access all contained items, call JSON.Object(), this method will return map[interface{}]*JSON
fields := json.Object()
for _, f := range fields {
// do something...
}
Get contained items count by calling JSON.Len()
fmt.Println("len:", json.Len())
JSON Array
Json array represented as JSON with kind of Array. For adding a new value, call JSON.AddItem() with param val. Will panic if val is not valid json value
json.AddItem("Hello world")
Get contained items count by calling JSON.Len()
fmt.Println("len:", json.Len())
To delete an item, call json.DeleteItem() with param i as array index
if json.DeleteItem(2) {
fmt.Println("item deleted")
} else {
fmt.Println("item is not exist")
}
Get all items by calling JSON.Array()
items := json.Array()
for _, item := range items {
// do something
}
Additional Note
When an item is edited inside JSON, the contained raw json will automatically re-generated.
DO NOT PERFORM ANY SETTER OR GETTER METHODS CONCURRENTLY
Documentation and Examples
See Documentation for more information. There's also some examples you can look up to
License
MIT
Documentation
¶
Overview ¶
Package jsonextract is a library for extracting any valid JSONs from given source
Index ¶
- Constants
- func Save(data []*JSON) error
- func SaveToPath(data []*JSON, path string) error
- type JSON
- func (json *JSON) AddField(key interface{}, val interface{})
- func (json *JSON) AddItem(val interface{})
- func (json *JSON) Array() []*JSON
- func (json *JSON) Boolean() bool
- func (json *JSON) Bytes() []byte
- func (json *JSON) DeleteField(key interface{}) bool
- func (json *JSON) DeleteItem(i int) bool
- func (json *JSON) Float() float64
- func (json *JSON) Integer() int64
- func (json *JSON) Kind() int
- func (json *JSON) Len() int
- func (json *JSON) Object() map[interface{}]*JSON
- func (json *JSON) Runes() []rune
- func (json *JSON) SetBool(b bool)
- func (json *JSON) SetFloat(i float64)
- func (json *JSON) SetInt(i int64)
- func (json *JSON) SetStr(str string)
- func (json *JSON) String() string
Constants ¶
const ( Object = iota Array String Integer Float Boolean Null )
JSON kinds
Variables ¶
This section is empty.
Functions ¶
func SaveToPath ¶
SaveToPath save extracted JSONs to a file path
Types ¶
type JSON ¶
type JSON struct {
// contains filtered or unexported fields
}
JSON represent json val
func FromReader ¶
FromReader extract JSONs from reader io.Reader
func (*JSON) AddField ¶
func (json *JSON) AddField(key interface{}, val interface{})
AddField add new field to object. Will panic if kind is not Object. Will panic if val is invalid json value. Valid key is string or integer type. If val is map, and key is not string nor an integer type, panic will occur
func (*JSON) AddItem ¶
func (json *JSON) AddItem(val interface{})
AddItem add new item in json array. Will panic if kind is not Array. Will panic if val is invalid json value
func (*JSON) DeleteField ¶
DeleteField delete object field by key. Will panic if kind is not Object. key must be string or an integer type, otherwise panic will occur
func (*JSON) DeleteItem ¶
DeleteItem delete element on index i. Will panic if kind is not Array. Will panic if i bigger than items count minus 1 (len(vals)-1, the last index). If item is existed, true is returned, otherwise false
func (*JSON) Len ¶
Len return items count inside JSON. If JSON is not Array or Object, Len will return 0, so please check the JSON kind first
Source Files
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Directories
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| Path | Synopsis |
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examples
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array
command
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boolean
command
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edit-val/array
command
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edit-val/object
command
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heavy
command
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null
command
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numeric
command
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object
command
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string
command
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