Example #1
0
func ExampleNewBranchingPipeline() {
	logger.LogLevel = logger.LevelSilent

	// This example is very contrived, but we'll first create
	// DataProcessors that will spit out strings, do some basic
	// transformation, and then filter out all the ones that don't
	// match "HELLO".
	hello := processors.NewIoReader(strings.NewReader("Hello world"))
	hola := processors.NewIoReader(strings.NewReader("Hola mundo"))
	bonjour := processors.NewIoReader(strings.NewReader("Bonjour monde"))
	upperCaser := processors.NewFuncTransformer(func(d data.JSON) data.JSON {
		return data.JSON(strings.ToUpper(string(d)))
	})
	lowerCaser := processors.NewFuncTransformer(func(d data.JSON) data.JSON {
		return data.JSON(strings.ToLower(string(d)))
	})
	helloMatcher := processors.NewRegexpMatcher("HELLO")
	stdout := processors.NewIoWriter(os.Stdout)

	// Create the PipelineLayout that will run the DataProcessors
	layout, err := ratchet.NewPipelineLayout(
		// Stage 1 - spits out hello world in a few languages
		ratchet.NewPipelineStage(
			ratchet.Do(hello).Outputs(upperCaser, lowerCaser),
			ratchet.Do(hola).Outputs(upperCaser),
			ratchet.Do(bonjour).Outputs(lowerCaser),
		),
		// Stage 2 - transforms strings to upper and lower case
		ratchet.NewPipelineStage(
			ratchet.Do(upperCaser).Outputs(helloMatcher),
			ratchet.Do(lowerCaser).Outputs(helloMatcher),
		),
		// Stage 3 - only lets through strings that match "hello"
		ratchet.NewPipelineStage(
			ratchet.Do(helloMatcher).Outputs(stdout),
		),
		// Stage 4 - prints to STDOUT
		ratchet.NewPipelineStage(
			ratchet.Do(stdout),
		),
	)
	if err != nil {
		panic(err.Error())
	}

	// Create and run the Pipeline
	pipeline := ratchet.NewBranchingPipeline(layout)
	err = <-pipeline.Run()

	if err != nil {
		fmt.Println("An error occurred in the ratchet pipeline:", err.Error())
	}

	// Output:
	// HELLO WORLD
}
Example #2
0
func ExampleNewPipeline() {
	logger.LogLevel = logger.LevelSilent

	// A basic pipeline is created using one or more DataProcessor instances.
	hello := processors.NewIoReader(strings.NewReader("Hello world!"))
	stdout := processors.NewIoWriter(os.Stdout)
	pipeline := ratchet.NewPipeline(hello, stdout)

	err := <-pipeline.Run()

	if err != nil {
		fmt.Println("An error occurred in the ratchet pipeline:", err.Error())
	}

	// Output:
	// Hello world!
}
Example #3
0
func ExampleGetRequest() {
	logger.LogLevel = logger.LevelSilent

	getGoogle, err := processors.NewHTTPRequest("GET", "http://www.google.com", nil)
	if err != nil {
		panic(err)
	}
	// this is just a really basic checking function so we can have
	// determinable example output.
	checkHTML := processors.NewFuncTransformer(func(d data.JSON) data.JSON {
		output := "Got HTML?\n"
		if strings.Contains(strings.ToLower(string(d)), "html") {
			output += "YES\n"
		} else {
			output += "NO\n"
		}
		output += "HTML contains Google Search?\n"
		if strings.Contains(string(d), "Google Search") {
			output += "YES\n"
		} else {
			output += "NO\n"
		}
		return data.JSON(output)
	})
	stdout := processors.NewIoWriter(os.Stdout)
	pipeline := ratchet.NewPipeline(getGoogle, checkHTML, stdout)

	err = <-pipeline.Run()

	if err != nil {
		fmt.Println("An error occurred in the ratchet pipeline:", err.Error())
	}

	// Output:
	// Got HTML?
	// YES
	// HTML contains Google Search?
	// YES
}