When having an executable file to make a certain operation, this execution can be integrated in SNAP in order to define an adapter that can be used multiple times, redistibuted and also chained with other operations from SNAP.
Step-by-step guide
There are two ways to create an adapter over an executable:
- Creating and running the adapter by using the SNAP application, which has user-friendly forms for this operations
- Creating the adapter files by using a text editor and a jar packager (for more experimented users/developers)
In order to use one of this two ways, it is necessary to know the format of the adapter's files. The adapter consists in a folder or a jar file; the name of the folder or jar file is the alias of the adapter. The folder/jar file should contain:
- a file called <adapter_alias>-template.vm, which is a velocity template that contains the command line parameters of the execution, each parameter on a separate line
- a subfolder called META-INF
- a file called descriptor.xml under the META-INF subfolder
The xml descriptor file should have the format (tag hierarchy) :
- the root tag is called operator. This tag contains the following children:
- the tag name. This tag content coresponds to the unique name that the operator will be registered with in SNAP context
- the tag operatorClass should contain the value org.esa.snap.framework.gpf.operators.tooladapter.ToolAdapterOp since this is the class of the adapters operators
- the tag alias. The content of this tag should match the name of the operator's folder