Version

    Normalizer

    Normalizer 64x64

    Short description

    Ports

    Metadata

    Normalizer attributes

    Details

    CTL interface

    Java interface

    Examples

    Best practices

    See also

    If you’re interested in learning more about this subject, we offer the Transforming Groups of Records, Normalization course in our CloverDX Academy.

    Short description

    Normalizer creates one or more output records from each single input record. Input records do not have to be sorted.

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

    -

    1

    1

    Ports

    Port type Number Required Description Metadata

    Input

    0

    For input data records

    Any1

    Output

    0

    For normalized data records

    Any2

    Metadata

    Normalizer does not propagate metadata.

    Normalizer does not have any metadata template.

    Normalizer does not require any specific metadata fields.

    Normalizer attributes

    Attribute Req Description Possible values

    Basic

    Normalize

    [1]

    The definition of the way how records should be normalized, written in the graph in CTL or Java.

    Normalize URL

    [1]

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

    Normalize class

    [1]

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

    Normalize source charset

    Encoding of an external file defining the transformation.

    The default encoding depends on DEFAULT_SOURCE_CODE_CHARSET in defaultProperties.

    E.g. UTF-8

    Deprecated

    Error actions

    Definition of the action that should be performed when the specified transformation returns some 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 specified.

    Details

    Normalizer requires transformation. The transformation can be defined in CTL (see CTL interface) or in Java (see Java interface).

    The transformation is defined using several functions. Each of them has its own purpose. The order of function calls is depicted in diagram below.

    Normalizer diagram
    Figure 406. Normalizer code workflow

    The number of calls of transform() function depends on the result of the count() (or countOnError()) function.

    CTL interface

    CTL Templates for Normalizer

    Access to input and output fields

    The transformation written in CTL uses a CTL template for Normalizer. Only the functions count() and transform() are mandatory. Other functions are optional.

    Once you have written your transformation, you can also convert it to Java language code using the corresponding button in the upper right corner of the tab.

    CTL Templates for Normalizer
    Table 72. Functions in Normalizer
    CTL Template Functions

    boolean init()

    Required

    No

    Description

    Initializes the component, sets up the environment, global variables.

    Invocation

    Called before processing the first record.

    Returns

    true | false (in case of false graph fails)

    integer count()

    Required

    yes

    Input Parameters

    none

    Returns

    The returned number defines the number of new output records that will be created by the transform() function.

    If the count() function returns 0, the subsequent call of transform() is skipped (transform() is called zero times).

    Invocation

    Called repeatedly, once for each input record

    Description

    For each input record it generates the number of output records that will be created from this input.

    If count() fails and user has not defined any countOnError(), the whole graph will fail.

    If any of the input records causes the count() function to fail, and if user has defined another function (countOnError()), processing continues in this countOnError() at the place where count() failed. The countOnError() function gets the information gathered by count() that was received from previously successfully processed input records. Also the error message and stack trace are passed to countOnError().

    Example

    function integer count() {
       customers = split($in.0.customers,"-");
       return length(customers);
    }

    integer transform(integer idx)

    Required

    yes

    Input Parameters

    integer idx integer numbers from 0 to count-1 (Here count is the number returned by the count() function.)

    Returns

    Integer number. The number corresponds to the return value of transformation. See Return values of transformations.

    Invocation

    Called repeatedly, once for each output record. The number of calls is defined by return value of function count().

    Description

    Creates output records.

    If transform() fails and the user has not defined any transformOnError(), the whole graph will fail.

    If any part of the transform() function for some output record causes fail of the transform() function, and if user has defined another function (transformOnError()), processing continues in this transformOnError() at the place where transform() failed. The transformOnError() function gets the information gathered by transform() that was received from previously successfully processed code. Also the error message and stack trace are passed to transformOnError().

    Example

    function integer transform(integer idx) {
       myString = customers[idx];
       $out.0.OneCustomer = str2integer(myString);
       $out.0.RecordNo = $in.0.recordNo;
       $out.0.OrderWithinRecord = idx;
       return OK;
    }

    void clean()

    Required

    no

    Input Parameters

    none

    Returns

    void

    Invocation

    Called repeatedly, once for each input record.

    The function is called after the corresponding call(s) of transform() function.

    Description

    Returns the component to the initial settings

    Example

    function void clean() {
       clear(customers);
    }

    integer countOnError(string errorMessage, string stackTrace)

    Required

    no

    Input Parameters

    string errorMessage

    string stackTrace

    Returns

    The returned number defines the number of new output records that will be created by thetransform() function.

    If the count() function returns 0, the subsequent call of transform() is skipped.

    Invocation

    Called if count() throws an exception.

    Description

    For each input record it generates the number of output records that will be created from this input.

    If any of the input records causes fail of the count() function, and if user has defined another function (countOnError()), processing continues in this countOnError() at the place where count() failed.

    Example

    function integer countOnError(
                      string errorMessage,
                      string stackTrace) {
       printErr(errorMessage);
       return 1;
    }

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

    Required

    no

    Input Parameters

    string errorMessage

    string stackTrace

    integer idx

    Returns

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

    Invocation

    Called if transform() throws an exception.

    Description

    Creates output records.

    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.

    The transformOnError() function gets the information gathered by transform() that was received from previously successfully processed code. Also the error message and stack trace are passed to transformOnError().

    Example

    function integer transformOnError(
                      string errorMessage,
                      string stackTrace,
                      integer idx) {
       printErr(errorMessage);
       printErr(stackTrace);
       $out.0.OneCustomerOnError = customers[idx];
       $out.0.RecordNo = $recordNo;
       $out.0.OrderWithinRecord = idx;
       return OK;
    }

    string getMessage()

    Required

    No

    Description

    Prints the error message specified and invoked by the user

    Invocation

    Called in any time specified by the user (called only when either count(), transform(), countOnError(), or transformOnError() 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 transform. 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.

    Access to input and output fields
    Input records or fields

    Input records or fields are accessible within the count(), countOnError(), transform() and transformOnError() functions only.

    Output records or fields

    Output records or fields 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!

    Java interface

    The transformation implements methods of the RecordNormalize interface and inherits other common methods from the Transform interface. See Common Java interfaces and Public CloverDX API.

    Following are the methods of RecordNormalize interface:

    • boolean init(Properties parameters, DataRecordMetadata sourceMetadata, DataRecordMetadata targetMetadata)

      Initializes normalize class/function. This method is called only once at the beginning of normalization process. Any object allocation/initialization should happen here.

    • int count(DataRecord source)

      Returns the number of output records which will be created from specified input record.

    • int countOnError(Exception exception, DataRecord source)

      Called only if count(DataRecord) throws an exception.

    • int transform(DataRecord source, DataRecord target, int idx)

      idx is a sequential number of output record (starting from 0). For detailed information about return values and their meaning, see Return values of transformations. In Normalizer, only ALL, 0, SKIP, and Error codes have some meaning.

    • int transformOnError(Exception exception, DataRecord source, DataRecord target, int idx)

      Called only if transform(DataRecord, DataRecord, int) throws an exception.

    • void clean()

      Finalizes current round/clean after current round - called after the transform method was called for the input record.

    Examples

    Converting multivalue fields to multiple records

    Input records contain group name and list of users of the group. Convert records into tuples having group name and one username.

    accounting  | [johnsmith, elisabethtaylor]
    development | [georgegreen, janegreen, peterbrown]
    Solution

    Define the transformation using Normalize attribute.

    //#CTL2
    
    function integer count() {
        return length($in.0.users);
    }
    
    function integer transform(integer idx) {
        $out.0.group = $in.0.group;
        $out.0.user = $in.0.users[idx];
        return OK;
    }

    Normalizer will return following records:

    accounting |johnsmith
    accounting |elisabethtaylor
    development|georgegreen
    development|janegreen
    development|peterbrown

    Best practices

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