Go

Call a JavaScript Function Returning an Object

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Demonstrates how to call a JavaScript function that returns an object. Go

    success := false

    // This is the JavaScript function we'll call:

    // function getSettings() {
    //     return {
    //         theme: "dark",
    //         notifications: true,
    //         version: 1.0
    //     };
    // }

    sbScript := chilkat.NewStringBuilder()
    sbScript.Append("function getSettings() {")
    sbScript.Append("    return {")
    sbScript.Append("        theme: \"dark\",")
    sbScript.Append("        notifications: true,")
    sbScript.Append("        version: 1.0")
    sbScript.Append("    };")
    sbScript.Append("}")

    js := chilkat.NewJs()

    result := chilkat.NewJsonObject()
    result.SetEmitCompact(false)

    // Call Eval to add the function to the context's global object
    success = js.Eval(sbScript,result)
    if success == false {
        // Examine the result for an exception.
        fmt.Println(*result.Emit())

        // Also examine the LastErrorText.
        fmt.Println(js.LastErrorText())
        sbScript.DisposeStringBuilder()
        js.DisposeJs()
        result.DisposeJsonObject()
        return
    }

    // ------------------------------------------------------------------------------
    // Call the function getSettings()

    funcCall := chilkat.NewJsonObject()

    // Create JSON specifying the function name and arguments
    // The function has no arguments, so we only specify the name.

    // {
    //   "name": "getSettings",
    // }

    funcCall.UpdateString("name","getSettings")

    success = js.CallFunction(funcCall,result)
    if success == false {
        // Examine the result for an exception.
        fmt.Println(*result.Emit())

        // Also examine the LastErrorText.
        fmt.Println(js.LastErrorText())
        sbScript.DisposeStringBuilder()
        js.DisposeJs()
        result.DisposeJsonObject()
        funcCall.DisposeJsonObject()
        return
    }

    fmt.Println(*result.Emit())

    // Output:
    // {
    //   "type": "object",
    //   "value": {
    //     "theme": "dark",
    //     "notifications": true,
    //     "version": 1
    //   }
    // }

    // Examine the object's members
    fmt.Println("theme: ", *result.StringOf("value.theme"))
    fmt.Println("notifications: ", *result.BoolOf("value.notifications"))
    fmt.Println("version: ", result.IntOf("value.version"))

    // Output:
    // theme: dark
    // notifications: True
    // version: 1

    sbScript.DisposeStringBuilder()
    js.DisposeJs()
    result.DisposeJsonObject()
    funcCall.DisposeJsonObject()