DataGenerator

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Short Summary

DataGenerator generates data.

Component	Data source	Input ports	Output ports	Each to all outputs¹⁾	Different to different outputs²⁾	Transformation	Transf. req.	Java	CTL
DataGenerator	generated	0	1-N	no	yes	yes	1)	yes	yes

Legend

1) Component sends each data record to all connected output ports.

2) Component sends different data records to different output ports using return values of the transformation. See Return Values of Transformations for more information.

Abstract

DataGenerator generates data according to some pattern instead of reading data from file, database, or any other data source. To generate data, a generate transformation may be defined. It uses a CTL template for DataGenerator or implements a RecordGenerate interface. Its methods are listed below. Component can send different records to different output ports using Return Values of Transformations.

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Ports

Port type	Number	Required	Description	Metadata
Output	0	yes	For generated data records	Any¹⁾
Output	1-N	no	For generated data records	Output 0

Legend:

1): Metadata on all output ports can use Autofilling Functions.

DataGenerator Attributes

Attribute	Req	Description	Possible values
Basic
Generator	1)	Definition of records should be generated written in the graph in CTL or Java.
Generator URL	1)	Name of external file, including path, containing the definition of the way how records should be generated written in CTL or Java.
Generator class	1)	Name of external class defining the way how records should be generated.
Number of records to generate	yes	Number of records to be generated.
Deprecated
Record pattern	2)	String consisting of all fields of generated records that are constant. It does not contain values of random or sequence fields.
Random fields	2)	Sequence of individual field ranges separated by semicolon. Individual ranges are defined by their minimum and maximum values. Minimum value is included in the range, maximum value is excluded from the range. Numeric data types represent numbers generated at random that are greater than or equal to the minimum value and less than the maximum value. If they are defined by the same value for both minimum and maximum, these fields will equal to such specified value. Fields of string and byte data type are defined by specifying their minimum and maximum length.
Sequence fields	2)	Fields generated by sequence. They are defined as the sequence of individual field mappings (`$field:=IdOfTheSequence`) separated by semicolon. The same sequence ID can be repeated and used for more fields at the same time.
Random seed	2)	Sets the seed of this random number generator using a single `long` seed. Assures that values of all fields remain stable on each graph run.	0-N

Legend:

1): One of these transformation attributes should be specified instead of the deprecated attributes marked by number 2. However, these new attributes are optional. Any of these transformation attributes must use a CTL template for DataGenerator or implement a RecordGenerate interface.

See CTL Scripting Specifics or Java Interfaces for DataGenerator for more information.

See also Defining Transformations for detailed information about transformations.

2): These attributes are deprecated now. Define one of the transformation attributes marked by number 1 instead.

Advanced Description

CTL Scripting Specifics

When you define any of the three new, transformation attributes, you must specify a transformation that assigns values to output fields. This can be done using the Transformations tab of the Transform Editor. However, you may find that you are unable to specify more advanced transformations using the easist approach. This is when you need to use CTL scripting.

For detailed information about CloudConnect Transformation Language see Part XI, CTL - CloudConnect 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 custom field mapping using the simple CTL scripting language.

DataGenerator uses the following transformation template:

CTL Templates for DataGenerator

This transformation template is used only in DataGenerator.

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

Figure 53.7. Source Tab of the Transform Editor in DataGenerator

Table 53.1. Functions in DataGenerator

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` (in case of `false` graph fails)
integer generate()
Required	yes
Input Parameters	none
Returns	Integer numbers. See Return Values of Transformations for detailed information.
Invocation	Called repeatedly for each output record
Description	Defines the structure and values of all fields of output record. If any part of the `generate()` function for some output record causes fail of the `generate()` function, and if user has defined another function (`generateOnError()`), processing continues in this `generateOnError()` at the place where `generate()` failed. If `generate()` fails and user has not defined any `generateOnError()`, the whole graph will fail. The `generateOnError()` function gets the information gathered by `generate()` that was get from previously successfully processed code. Also error message and stack trace are passed to `generateOnError()`.
Example	function integer generate() { myTestString = iif(randomBool(),"1","abc"); $0.name = randomString(3,5) + " " randomString(5,7); $0.salary = randomInteger(20000,40000); $0.testValue = str2integer(myTestString); return ALL; }
integer generateOnError(string errorMessage, string stackTrace)
Required	no
Input Parameters	`string errorMessage`
Input Parameters	`string stackTrace`
Returns	Integer numbers. See Return Values of Transformations for detailed information.
Invocation	Called if `generate()` throws an exception.
Description	Defines the structure and values of all fields of output record. If any part of the `generate()` function for some output record causes fail of the `generate()` function, and if user has defined another function (`generateOnError()`), processing continues in this `generateOnError()` at the place where `generate()` failed. If `generate()` fails and user has not defined any `generateOnError()`, the whole graph will fail. The `generateOnError()` function gets the information gathered by `generate()` that was get from previously successfully processed code. Also error message and stack trace are passed to `generateOnError()`.
Example	function integer generateOnError( string errorMessage, string stackTrace) { $0.name = randomString(3,5) + " " randomString(5,7); $0.salary = randomInteger(20000,40000); $0.stringTestValue = "myTestString is abc"; return ALL; }
string getMessage()
Required	No
Description	Prints error message specified and invocated by user (called only when either `generate()` or `generateOnError()` returns value less than or equal to -2).
Invocation	Called in any time specified by user
Returns	`string`
void preExecute()
Required	No
Input parameters	None
Returns	`void`
Description	May be used to allocate and initialize resources required by the generate. 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 any resources allocated within the `preExecute()` function.
Invocation	Called during each graph run after the entire transform was executed.

	Important
	Output records or fields Output records or fields are accessible within the `generate()` and `generateOnError()` functions only. All of the other CTL template functions do not allow to access outputs.

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

Java Interfaces for DataGenerator

The transformation implements methods of the RecordGenerate interface and inherits other common methods from the Transform interface. See Common Java Interfaces.

Following are the methods of RecordGenerate interface:

boolean init(Properties parameters, DataRecordMetadata[] targetMetadata)
Initializes generate class/function. This method is called only once at the beginning of generate process. Any object allocation/initialization should happen here.

int generate(DataRecord[] target)

Performs generator of target records. This method is called as one step in generate flow of records.

	Note
	This method allows to distribute different records to different connected output ports according to the value returned for them. See Return Values of Transformations for more information about return values and their meaning.

int generateOnError(Exception exception, DataRecord[] target)
Performs generator of target records. This method is called as one step in generate flow of records. Called only if generate(DataRecord[]) throws an exception.

void signal(Object signalObject)
Method which can be used for signaling into generator that something outside happened.

Object getSemiResult()
Method which can be used for getting intermediate results out of generation. May or may not be implemented.

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