PureBasic

Call a JavaScript Function Returning an Object

See more JavaScript Examples

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

IncludeFile "CkJs.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkJsonObject.pb"

Procedure ChilkatExample()

    success.i = 0

    ; This is the JavaScript function we'll call:

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

    sbScript.i = CkStringBuilder::ckCreate()
    If sbScript.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkStringBuilder::ckAppend(sbScript,"function getSettings() {")
    CkStringBuilder::ckAppend(sbScript,"    return {")
    CkStringBuilder::ckAppend(sbScript,"        theme: " + Chr(34) + "dark" + Chr(34) + ",")
    CkStringBuilder::ckAppend(sbScript,"        notifications: true,")
    CkStringBuilder::ckAppend(sbScript,"        version: 1.0")
    CkStringBuilder::ckAppend(sbScript,"    };")
    CkStringBuilder::ckAppend(sbScript,"}")

    js.i = CkJs::ckCreate()
    If js.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    result.i = CkJsonObject::ckCreate()
    If result.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::setCkEmitCompact(result, 0)

    ; Call Eval to add the function to the context's global object
    success = CkJs::ckEval(js,sbScript,result)
    If success = 0
        ; Examine the result for an exception.
        Debug CkJsonObject::ckEmit(result)

        ; Also examine the LastErrorText.
        Debug CkJs::ckLastErrorText(js)
        CkStringBuilder::ckDispose(sbScript)
        CkJs::ckDispose(js)
        CkJsonObject::ckDispose(result)
        ProcedureReturn
    EndIf

    ; ------------------------------------------------------------------------------
    ; Call the function getSettings()

    funcCall.i = CkJsonObject::ckCreate()
    If funcCall.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

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

    ; {
    ;   "name": "getSettings",
    ; }

    CkJsonObject::ckUpdateString(funcCall,"name","getSettings")

    success = CkJs::ckCallFunction(js,funcCall,result)
    If success = 0
        ; Examine the result for an exception.
        Debug CkJsonObject::ckEmit(result)

        ; Also examine the LastErrorText.
        Debug CkJs::ckLastErrorText(js)
        CkStringBuilder::ckDispose(sbScript)
        CkJs::ckDispose(js)
        CkJsonObject::ckDispose(result)
        CkJsonObject::ckDispose(funcCall)
        ProcedureReturn
    EndIf

    Debug CkJsonObject::ckEmit(result)

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

    ; Examine the object's members
    Debug "theme: " + CkJsonObject::ckStringOf(result,"value.theme")
    Debug "notifications: " + Str(CkJsonObject::ckBoolOf(result,"value.notifications"))
    Debug "version: " + Str(CkJsonObject::ckIntOf(result,"value.version"))

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


    CkStringBuilder::ckDispose(sbScript)
    CkJs::ckDispose(js)
    CkJsonObject::ckDispose(result)
    CkJsonObject::ckDispose(funcCall)


    ProcedureReturn
EndProcedure