Version

    Map

    Reformat NEW 64x64

    Short Description

    Ports

    Metadata

    Map Attributes

    Details

    Examples

    Best Practices

    See also

    Short Description

    Map manipulates record’s structure or content. This component was formerly called Reformat.

    Component Same input metadata Sorted inputs Inputs Outputs Java CTL Auto-propagated metadata

    Map

    -

    1

    1-N

    Ports

    Port type Number Required Description Metadata

    Input

    0

    for input data records

    Any(In0)

    Output

    0

    for transformed data records

    Any(Out0)

    1-n

    for transformed data records

    Any(OutPortNo)

    This component has one input port and at least one output port.

    The component can send different records to different output ports or even send the same data record to more output ports.

    Metadata

    Map propagates metadata from the input port to the output port (from left to right), but it does not propagate metadata from the output port to the input port (from right to left).

    Metadata propagation through Map has low priority.

    Map Attributes

    Attribute Req Description Possible values

    Basic

    Transform

    [1]

    The definition of how records should be mapped. Written in the graph source either in CTL or in Java.

    Transform URL

    [1]

    The name of the external file, including the path, containing the definition of the way how records should be mapped; written in CTL or Java.

    Transform class

    [1]

    The name of an external class defining the way how records should be mapped.

    Transform source charset

    Encoding of external file defining the transformation.

    The default encoding depends on DEFAULT_SOURCE_CODE_CHARSET in defaultProperties.

    E.g. UTF-8

    Deprecated

    Error actions

    The definition of an action that should be performed when the specified transformation returns an Error code. See Return Values of Transformations.

    Error log

    The URL of the file to which error messages for specified Error actions should be written. If not set, they are written to Console.

    1

     One of these must be specified. Any of these transformation attributes uses a CTL template for Map or implements a RecordTransform interface.

    For more information, see CTL Scripting Specifics or Java Interfaces for Map.

    For detailed information about transformations, see also Defining Transformations.

    Details

    Map receives potentially unsorted data through the single input port, transforms each of them in a user-specified way and sends the resulting record to the port(s) specified by the user. Return values of the transformation are numbers of output port(s) to which data record will be sent.

    A transformation must be defined. The transformation uses a CTL template for Map, implements a RecordTransform interface or inherits from a DataRecordTransform superclass. The interface methods are listed below.

    CTL Scripting Specifics

    When you define any of the three transformation attributes, specify a transformation that assigns a number of output port to each input record.

    For detailed information about CloverDX Transformation Language, see CTL2 - CloverDX Transformation Language. (CTL is a full-fledged, yet simple language that allows you to perform almost any imaginable transformation.)

    CTL scripting allows you to specify a custom transformation using the simple CTL scripting language.

    CTL Templates for Map

    Map uses the same transformation template as DataIntersection and Joiners. For more information, see CTL Templates for Joiners.

    Java Interfaces for Map

    Map implements the same interface as DataIntersection and Joiners. For more information, see Java Interfaces for Joiners and Public CloverDX API.

    Examples

    Using Map to drop field(s)

    Splitting the records

    Filtering records

    Using Map to drop field(s)

    This example shows a way to use Map to drop unnecessary metadata fields.

    Input metadata contains the firstname, surname and address fields. Output metadata contains the firstname and surname fields. Drop the address field.

    Solution

    In Map, specify the Transform attribute.

    Attribute Value

    Transform

    function integer transform() {
        $out.0.firstname = $in.0.firstname;
        $out.0.surname = $in.0.surname;
    
        return ALL;
    }

    You can use $out.0.* = $in.0.*; instead of specifying the mapping of particular fields.

    Splitting the records

    This example shows a way to use Map to split one record to multiple parts and send each part to a different output port.

    Input metadata contains the ID, firstname, surname and address fields. Send ID, firstname and surname to the first output port and ID and address to the second output port.

    Solution

    In Map, set the Transform attribute.

    Attribute Value

    Transform

    function integer transform() {
        $out.0.ID = $in.0.ID;
        $out.0.firstname = $in.0.firstname;
    	$out.0.surname = $in.0.surname;
    
        $out.1.ID = $in.0.ID;
        $out.1.address = $in.0.address;
    
        return ALL;
    }
    Filtering records

    Map can be used as a filter.

    Input metadata contains the ID and color fields. Valid colors are red, green, or blue. Send red items to the first output port; green items to the second output port; and blue items to the third output port. Items without correct color should be send to the fourth output port.

    Solution
    Attribute Value

    Transform

    function integer transform() {
        if ( $in.0.color == "red" ) {
            $out.0.* = $in.0.*;
            return 0;
        }
        if ( $in.0.color == "green" ) {
            $out.1.* = $in.0.*;
            return 1;
        }
        if ( $in.0.color == "blue") {
            $out.2.* = $in.0.*;
            return 2;
        }
    
        $out.3.* = $in.0.*;
        return 3;
    }

    There are components specialized on filtering of records: Filter and Validator.

    Best Practices

    Use Map To
    • Drop unwanted fields

    • Validate fields using functions or regular expressions

    • Calculate new or modify existing fields

    • Convert data types

    If the transformation is specified in an external file (with Transform URL), we recommend users to explicitly specify Transform source charset.