Filter Configurations

The filter configuration is a dictionary used to configure the pipeline steps for a particular filter. The configuration settings are specific for each filter type. The following table shows the three valid configuration formats:

Configuration Formats

Option	Format	fail_silently	Additional Options
Full Dictionary Configuration	Dictionary with pipeline list	Configurable (True/False)	Allowed
Pipeline List Configuration	List of pipeline steps	Always True	Not allowed
Single Step Configuration	Single pipeline step string	Always True	Not allowed

Detailed Examples

Full Dictionary Configuration

This is the most detailed option and from it, the others can be derived. This configuration is very explicit. It contains the list of functions for the pipeline and any other optional setting for a filter.

OPEN_EDX_FILTERS_CONFIG = {
    "<filter_type>": {  # Replace with the specific filter type
        "fail_silently": True,  # Set to True to ignore exceptions and continue the pipeline
        "pipeline": [
            "module.path.PipelineStep0",  # Replace with the actual module path and class name
            "module.path.PipelineStep1",
            # Add more steps as needed
            "module.path.PipelineStepN",
        ],
        "other_option": "value1",
        "another_option": "value2",
        # Add other options as needed
    },
}

Configuration Elements:

• <filter_type> is the filter type.

• fail_silently is a boolean flag indicating whether the pipeline should continue executing the next steps when a runtime exception is raised by a pipeline step.

  • If True, when a pipeline step raises a runtime exception (e.g., ImportError or AttributeError) that the developer does not intentionally raise during the filter’s execution, the exception will not be propagated, and the execution will resume, i.e., the next steps will be executed.

  • If False, the exception will be propagated, and the execution will stop returning control to the caller.

• pipeline is a list of paths for each pipeline step. Each path is a string with the following format: module.path.PipelineStepClassName. The module path is the path to the module where the pipeline step class was implemented and the class name is the name of the class that implements the run_filter method to be executed when the filter is triggered.

• other_option and another_option are placeholders for any other options that may be required by the pipeline steps.

Exception Handling Example:

OPEN_EDX_FILTERS_CONFIG = {
    "<filter_type>": {
        "fail_silently": True,
        "pipeline": [
            "non_existing_module.PipelineStep",
            "existing_module.NonExistingPipelineStep",
            "module.path.PipelineStep",
        ]
    },
}

Behavior:

• The pipeline tooling will catch the ImportError exception raised by the first step and continue executing the next steps.

• The pipeline tooling will catch the AttributeError exception raised by the second step and continue executing the next steps.

• The pipeline tooling will execute the third step successfully and then return the result.

Pipeline List Configuration

This option only considers the configuration of the list of functions to be run by the pipeline. The fail_silently option is always set to True and no other additional options are allowed.

OPEN_EDX_FILTERS_CONFIG = {
    "<filter_type>": [
        "module.path.PipelineStep0",  # Replace with the actual module path and class name
        "module.path.PipelineStep1",
        # Add more steps as needed
        "module.path.PipelineStepN",
    ],
}

Configuration Elements:

• <filter_type> is the filter type and the value of this key is a list of paths for each pipeline step.

Exception Handling Example:

OPEN_EDX_FILTERS_CONFIG = {
    "<filter_type>": [
        "non_existing_module.PipelineStep",
        "existing_module.NonExistingPipelineStep",
        "module.path.PipelineStep",
    ],
}

Behavior: The same behavior as for non-existent pipeline methods in Full Dictionary Configuration will be applied.

Single Step Configuration

This option considers that there’s just one function to be run. The fail_silently option is always set to True and no other additional options are allowed.

OPEN_EDX_FILTERS_CONFIG = {
    "<filter_type>": "module.path.PipelineStep",
}

Configuration Elements:

• <filter_type> is the filter type and the value of this key is a path for the unique pipeline step.

Exception Handling Examples:

OPEN_EDX_FILTERS_CONFIG = {
    "<filter_type>": "non_existing_module.PipelineStep",
    # or
    "<filter_type>": "existing_module.NonExistingPipelineStep",
    # or
    "<filter_type>": "existing_module.PipelineStep",
}

Behavior:

• The pipeline tooling will catch the ImportError exception raised by the first step and return control to the caller.

• The pipeline tooling will catch the AttributeError exception raised by the second step and return control to the caller.

• The pipeline tooling will execute the step successfully and return the result.

For more details on the configuration, see 2. Configuration for filters in the Hooks Extension Framework.

Maintenance chart

Review Date	Reviewer	Release	Test situation
2025-02-13	Maria Grimaldi	Sumac	Pass.