data

Documentation

Overview

Package data holds custom types and functions for passing JSON between ratchet stages.

Index

• func ObjectsFromJSON(d JSON) ([]map[string]interface{}, error)
• func ParseJSON(d JSON, v interface{}) error
• func ParseJSONSilent(d JSON, v interface{}) error
• type JSON
  • func JSONFromHeaderAndRows(header []string, rows [][]interface{}) (JSON, error)
  • func NewJSON(v interface{}) (JSON, error)

Examples

• JSONFromHeaderAndRows
• NewJSON
• ObjectsFromJSON
• ParseJSON

Functions

func ObjectsFromJSON

func ObjectsFromJSON(d JSON) ([]map[string]interface{}, error)

ObjectsFromJSON is a helper for parsing JSON into a slice of generic maps/objects. The use-case is when a stage is expecting to receive either a JSON object or an array of JSON objects, and want to deal with it in a generic fashion.

Example

package main

import (
	"fmt"

	"github.com/dailyburn/ratchet/data"
)

func main() {
	d := []byte(`[{"One":1},
		      {"Two":2}]`)

	objects, _ := data.ObjectsFromJSON(d)

	fmt.Println(fmt.Sprintf("%+v", objects))
}

Output:

[map[One:1] map[Two:2]]

func ParseJSON

func ParseJSON(d JSON, v interface{}) error

ParseJSON is a simple wrapper for json.Unmarshal

Example

package main

import (
	"fmt"

	"github.com/dailyburn/ratchet/data"
)

type testStruct struct {
	A int
	B int
}

func main() {
	d := []byte(`{"A":1,"B":2}`)
	t := testStruct{}
	data.ParseJSON(d, &t)

	fmt.Println(fmt.Sprintf("%+v", t))
}

Output:

{A:1 B:2}

func ParseJSONSilent

func ParseJSONSilent(d JSON, v interface{}) error

ParseJSONSilent won't log output when unmarshaling fails. It can be used in cases where failure is expected.

Types

type JSON

type JSON []byte

JSON is the data type that is passed along all data channels. Under the covers, JSON is simply a []byte containing JSON data.

func JSONFromHeaderAndRows

func JSONFromHeaderAndRows(header []string, rows [][]interface{}) (JSON, error)

JSONFromHeaderAndRows takes the given header and rows of values, and turns it into a JSON array of objects.

Example

package main

import (
	"fmt"

	"github.com/dailyburn/ratchet/data"
)

func main() {
	header := []string{"A", "B", "C"}
	rows := [][]interface{}{
		[]interface{}{1, 2, 3},
		[]interface{}{4, 5, 6},
	}

	d, _ := data.JSONFromHeaderAndRows(header, rows)

	fmt.Println(fmt.Sprintf("%+v", string(d)))
}

Output:

[{"A":1,"B":2,"C":3},{"A":4,"B":5,"C":6}]

func NewJSON

func NewJSON(v interface{}) (JSON, error)

NewJSON is a simple wrapper for json.Marshal.

Example

package main

import (
	"fmt"

	"github.com/dailyburn/ratchet/data"
)

type testStruct struct {
	A int
	B int
}

func main() {
	t := testStruct{A: 1, B: 2}

	d, _ := data.NewJSON(t)

	fmt.Println(string(d))
}

Output:

{"A":1,"B":2}