Dynamic Routing with Route Parameters — Let’s Learn Adonis 5, Lesson 2.1

Tom Gobich | Adocasts.com
8 min readSep 4, 2022

View all lessons in the Let’s Learn Adonis 5 series here.

Route parameters give us a way to add dynamic routes to our route definitions so that we don’t have to define a route for each identity that’s within our database.

For example, without route parameters, in order to have a route for posts with an id of 1, 2, and 3, we'd need to manually define the same route for each individual id. That quickly becomes a scalability issue, as you can see below.

Route.get('/posts/1', () => 'get post 1')
Route.get('/posts/2', () => 'get post 2')
Route.get('/posts/3', () => 'get post 3')
Route.put('/posts/1', () => 'get post 1')
Route.put('/posts/2', () => 'get post 2')
Route.put('/posts/3', () => 'get post 3')
Route.delete('/posts/1', () => 'get post 1')
Route.delete('/posts/2', () => 'get post 2')
Route.delete('/posts/3', () => 'get post 3')

With route parameters, we can make the id portion of the URL dynamic so that we only need to define the route once.

Defining A Route Parameter

Route parameters in Adonis start with a colon (:), followed by whatever you want to name that parameter. Typically you'd name the route parameter after what value it should hold.

Route.get('/posts/:id', () => 'get post with provided id')
Route.put('/posts/:id', () => 'update post with provided id')
Route.delete('/posts/:id', () => 'delete post with provided id')

Here, we’ve named our route parameter id to signify that the route parameter is meant to be a post id value. So regardless if we send a GET request for http://localhost:3333/posts/1, http://localhost:3333/posts/2, or http://localhost:3333/posts/3 our GET route definition will be used.

Of course, be mindful of this because our :id route parameter will match anything that's passed into that position in the url. For example, http://localhost:3333/posts/not-an-id.

Accessing A Route Parameter Value

Tom Gobich | Adocasts.com

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