Version

    CTL templates for Joiners

    This transformation template is used in every Joiner and also in Map and DataIntersection.

    Here is an example of how the Source tab for defining the transformation in CTL looks.

    300220
    Figure 410. Source tab of the Transform editor in Joiners
    Table 76. Functions in Joiners, DataIntersection and Map
    CTL Template Functions

    boolean init()

    Required

    No

    Description

    Initialize the component, setup the environment, global variables.

    Invocation

    Called before processing the first record.

    Returns

    true | false (if false, the graph fails)

    integer transform()

    Required

    yes

    Input Parameters

    none

    Returns

    Integer numbers. For detailed information, see Return values of transformations.

    Invocation

    Called repeatedly for each set of joined or intersected input records (Joiners and DataIntersection) and for each input record (Map).

    Description

    Allows you to map input fields to the output fields using a script. If any part of the transform() function for some output record causes fail of the transform() function, and if the user has defined another function (transformOnError()), processing continues in this transformOnError() at the place where transform() failed.

    If transform() fails and the user has not defined any transformOnError(), the whole graph will fail. The transformOnError() function gets the information gathered by transform() that was gotten from previously successfully processed code. Also an error message and stack trace are passed to transformOnError().

    Example

    function integer transform() {
       $out.0.name = $in.0.name;
       $out.0.address = $in.0.city + $in.0.street + $in.0.zip;
       $out.0.country = toUpper($in.0.country);
       return ALL;
    }

    integer transformOnError(string errorMessage, string stackTrace, integer idx)

    Required

    no

    Input Parameters

    string errorMessage

    string stackTrace

    Returns

    Integer numbers. For detailed information, see Return values of transformations.

    Invocation

    Called if transform() throws an exception.

    Description

    It creates output records. If any part of the transform() function for some output record causes fail of the function, and if the user has defined another function (transformOnError()), processing continues in this transformOnError() at the place where transform() failed.

    If transform() fails and the user has not defined any transformOnError(), the whole graph will fail. The transformOnError() function gets the information gathered by transform() that was gotten from previously successfully processed code. Also an error message and stack trace are passed to transformOnError().

    Example

    function integer transformOnError(
                           string errorMessage,
                           string stackTrace) {
       $in.0.name = $in.0.name;
       $in.0.address = $in.0.city + $in.0.street + $in.0.zip;
       $in.0.country = "country was empty";
       printErr(stackTrace);
       return ALL;
    }

    string getMessage()

    Required

    No

    Description

    Prints an error message specified and invoked by user.

    Invocation

    Called in any time specified by the user (called only when transform() returns value less than or equal to -2).

    Returns

    string

    void preExecute()

    Required

    No

    Input parameters

    None

    Returns

    void

    Description

    May be used to allocate and initialize resources required by the transformation. All resources allocated within this function should be released by the postExecute() function.

    Invocation

    Called during each graph run before the transform is executed.

    void postExecute()

    Required

    No

    Input parameters

    None

    Returns

    void

    Description

    Should be used to free up any resources allocated within the preExecute() function.

    Invocation

    Called during each graph run after the entire transform was executed.

    • Input records or fields and output records or fields

      Both inputs and outputs are accessible within the transform() and transformOnError() functions only.

    • All of the other CTL template functions allow to access neither inputs nor outputs.

    Remember that if you do not hold these rules, NPE will be thrown.