Internal or External Definition

    Each transformation can be defined as internal or external:

    • Internal transformation:

      An attribute like Transform, Denormalize, etc. must be defined.

      In such a case, the piece of code is written directly in the graph and can be seen in it.

    • External transformation:

      One of the following two kinds of attributes may be defined:

      • Transform URL, Denormalize URL, etc., for both Java and CTL

        The code is written in an external file. Also charset of such external file can be specified (Transform source charset, Denormalize source charset, etc.).

        For transformations written in Java, a folder with transformation source code needs to be specified as source for Java compiler so that the transformation may be executed successfully.

      • Transform class, Denormalize class, etc.

        It is a compiled Java class.

        The class must be in classpath so that the transformation may be executed successfully.

    Here we provide a brief overview:

    • Transform, Denormalize, etc.

      To define a transformation in a graph itself, you must use the Transform editor (or the Edit value dialog in the case of JMSReader, and JMSWriter components). In them, you can define a transformation located and visible in a graph itself. Transformation can be written in Java or CTL, as mentioned above.

      For more detailed information about the editor or the dialog, see Transform Editor or Edit Value Dialog.

    • Transform URL, Denormalize URL, etc.

      You can also use a transformation defined in some source file outside a graph. To locate the transformation source file, use the URL File Dialog. Each of the mentioned components can use this transformation definition. This file must contain the definition of the transformation written in either Java or CTL. In this case, transformation is located outside a graph.

      For more detailed information see URL File Dialog.

    • Transform class, Denormalize class, etc.

      In all transforming components, you can use some compiled transformation class. To do that, use the Open Type wizard. In this case, the transformation is located outside the graph.

      For more detailed information, see Open Type Dialog.

    More details about defining transformations can be found in the sections concerning corresponding components. Both transformation functions (required and optional) of CTL templates and Java interfaces are described there.

    Here we present a brief table with an overview of transformation-allowing components:

    Table 40.1. Transformations Overview

    ComponentTransformation requiredJavaCTLEach to all outputs[1]Different to different outputs[2]CTL templateJava interface
    DataGeneratorCTL Templates for DataGeneratorJava Interface
    JMSReader-Java Interfaces for JMSReader
    MultiLevelReader-Java Interfaces for MultiLevelReader
    JMSWriter---Java Interfaces for JMSWriter
    PartitionCTL Templates for Partition (or ParallelPartition)Java Interface
    DataIntersection--CTL Templates for DataIntersectionJava Interfaces for DataIntersection
    ReformatCTL Templates for ReformatJava Interfaces for Reformat
    Denormalizer--CTL TemplatesJava Interface
    Normalizer--CTL Templates for NormalizerJava Interface
    RollupCTL Templates for RollupJava Interface
    ExtHashJoin--CTL Templates for JoinersJava Interfaces for Joiners
    ExtMergeJoin--CTL Templates for JoinersJava Interfaces for Joiners
    LookupJoin--CTL Templates for JoinersJava Interfaces for Joiners
    DBJoin--CTL Templates for JoinersJava Interfaces for Joiners
    RelationalJoin--CTL Templates for JoinersJava Interfaces for Joiners
    Cluster Components

    [1]  If this is yes, each data record is always sent out through all connected output ports.

    [2]  If this is yes, each data record can be sent out through the connected output port whose number is returned by the transformation. For more information, see Return Values of Transformations.