transform

README

transform

Contains interfaces and methods for transforming data.

Documentation

Overview

Package transform provides functions for transforming data.

Index

• func Apply(ctx context.Context, tf []Transformer, mess ...*message.Message) ([]*message.Message, error)
• type Transformer
  • func New(ctx context.Context, cfg config.Config) (Transformer, error)

Examples

• Transformer

Functions

func Apply

func Apply(ctx context.Context, tf []Transformer, mess ...*message.Message) ([]*message.Message, error)

Types

type Transformer

type Transformer interface {
	Transform(context.Context, *message.Message) ([]*message.Message, error)
}

Transformer is the interface implemented by all transforms and provides the ability to transform data.

Example

package main

import (
	"context"
	"fmt"

	"github.com/brexhq/substation/config"
	"github.com/brexhq/substation/message"
	"github.com/brexhq/substation/transform"
)

func main() {
	ctx := context.TODO()

	// Copies the value of key "a" into key "b".
	cfg := config.Config{
		Type: "object_copy",
		Settings: map[string]interface{}{
			"object": map[string]interface{}{
				"key":     "a",
				"set_key": "b",
			},
		},
	}

	tf, err := transform.New(ctx, cfg)
	if err != nil {
		// handle err
		panic(err)
	}

	// Transformer is applied to a message.
	msg := message.New().SetData([]byte(`{"a":1}`))
	results, err := tf.Transform(ctx, msg)
	if err != nil {
		// handle err
		panic(err)
	}

	for _, c := range results {
		fmt.Println(string(c.Data()))
	}

}

Output:

{"a":1,"b":1}

func New

func New(ctx context.Context, cfg config.Config) (Transformer, error)

New returns a configured Transformer.