Filter agents

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If you have not read how to add metadata to Agent, please refer to Adding Metadata to Agent.

Having explained the process of adding attributes to an Agent Class, let's now delve into filtering Agent using these attributes effectively.

For this example, we will reuse the previous example where we defined an attribute called EXTENSIONS.
We will use this attribute to filter Agents capable to parse the input file.

recap

Here is a quick recap of the Base Class and our Agent Class.

Base.py

The Base Class has the attribute EXTENSIONS defined to None.

This means that by default, Agent will be able to parse every file, not restricted to specific extensions.

agents/base.py

class Base(ABC):
    NAME = "Base Agent"
    ACTIVATED = False
    VERSION = "0.0"
    MISSION = "No description"
    EXTENSIONS = None  # EXTENSIONS attribute, default is None

Agent my-parser

The Agent my-parser overrides the attribute EXTENSIONS to indicate file extensions he can parse.

agents/my-parser/__init__.py

class MyParserAgent(Base):
    NAME = "MyParser"
    ACTIVATED = True
    VERSION = "1.0"
    MISSION = "Yet another parser to parse awesome stuff"
    FILE = None
    EXTENSIONS = ["zip", "tar"]  # Attribute overrides, restrict to Zip and Tar archives

The Agents are retrieved through the get_enabled_agents function in /agents/__init__.py.

Just add your condition in this function to filter Agents to select. Here is an example with the EXTENSIONS attribute.

agents/__init__.py

def get_enabled_agents(agents):
    for agent in agents:
        if agents[agent].ACTIVATED:  # If Agent is activated
            if agents[agent].EXTENSIONS:  # If Agent overrides EXTENSIONS
                if any(ext == args.get('file', '').split('.')[-1]
                       for ext in agents[agent].EXTENSIONS):  # If file extension is in EXTENSIONS elements
                    yield agent
            else:
                yield agent