custom-router.md

Custom routers can be used to define custom routing logic for your application. This is useful when you need to implement a custom routing algorithm or when you need to integrate with an existing URL routing system.

---

Step 1: Creating a custom resolver

You may want to create a custom resolver to allow ReactPy to utilize an existing routing syntax.

To start off, you will need to create a subclass of #!python ReactPyResolver. Within this subclass, you have two attributes which you can modify to support your custom routing syntax:

• #!python param_pattern: A regular expression pattern that matches the parameters in your URL. This pattern must contain the regex named groups name and type.
• #!python converters: A dictionary that maps a type to it's respective regex pattern and a converter func.

=== "resolver.py"

```python
{% include "../../examples/python/custom_router_easy_resolver.py" %}
```

Step 2: Creating a custom router

Then, you can use this resolver to create your custom router...

=== "resolver.py"

```python
{% include "../../examples/python/custom_router_easy_router.py" %}
```