Injector

Description

Injector was created for those people that are developing special purpose transformations and want to 'inject' rows into the transformation using the Kettle API and Java. Among other things you can build 'headless' transformations with it: transformations that have no input at design time: do not read from file or database.

Options

Option	Definition
Step name	The name of this step as it appears in the transformation workspace.
Fieldname	Specify the field name of the rows to inject.
Type	Specify the type of data.
Length	For Number: Total number of significant figures in a number; For String: total length of string; For Date: length of printed output of the string.
Precision	For Number: Number of floating point digits; For String, Date, Boolean: unused.

Example

Here is some information on how to do it:

You can ask a Trans object for a RowProducer object
Also see the unit test case: org.pentaho.di.trans.RowProducerTest
Use this type of code:
```
Trans trans = new Trans(... TransMeta ...);
trans.prepareExecution(args);
RowProcuder rp = trans.addRowProducer(String stepname, int stepCopy);
```
After that you start the threads in the transformation. Then you can inject the rows while the transformation is running:
```
trans.startThreads();
...
rp.putRow(some row you need to inject);
...
```
You can also specify the rows you are expecting to be injected. This makes it easier to build transformations because you have the meta-data at design time.

See also the PDI SDK: "Embedding and Extending Pentaho Data Integration" within the Developer Guides