How to implement your own component

Skill level: Intermediate

TL;DR

Custom components just need to implement their respective protocol.

aviary’s components are designed to be modular and extensible. This means that you can easily implement your own components and use them just like the built-in ones.

There are the following types of components in aviary:

• CoordinatesFilter
• TileFetcher
• TilesProcessor

These are protocols that define the methods a component must have. Implementing them is straightforward as they only require you to implement the __call__ method.

Example

Implement a custom tiles processor

Let’s implement our own tiles processor called MyTilesProcessor.

First, we need to have a look at the TilesProcessor protocol. A tiles processor is a callable that takes a Tiles object, processes it, and returns it.

So, we need to implement the __call__ method in our class. We can also implement the __init__ method to initialize our tiles processor. This is useful if you need to pass any parameters to the tiles processor.

my_tiles_processor.py

import aviary


class MyTilesProcessor:

    def __init__(
        self,
        param_1: int,
        param_2: str,
    ) -> None:
        self._param_1 = param_1
        self._param_2 = param_2

    def __call__(
        self,
        tiles: aviary.Tiles,
    ) -> aviary.Tiles:
        # Process the tiles here
        return tiles

Now you can use MyTilesProcessor like any other tiles processor in aviary.

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Next step

Do you want to use custom components in the CLI?
Have a look at the How to register your own component guide.