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Filters: Searching Results

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Some of our dragon treasures are currently published and some are unpublished. That's thanks to DragonTreasureFactory, where we randomly publish some but not others.

Right now, the API is returning every last dragon treasure. In the future, we're going to make it so that our API automatically returns only published treasures. But to start, let's at least make it possible for our API clients to filter out unpublished results if they want to.

Hello ApiFilter

How? By Leveraging filters. API Platform comes with a bunch of built-in filters that allow you to filter the collections of results by text, booleans, dates and much more.

Here's how it works: above your class, add an attribute called ApiFilter.

There are typically two ingredients that you need to pass to this. The first is which filter class you want to use. And if you look at the documentation, there's a bunch of them, like one called BooleanFilter that we'll use now and another called SearchFilter that we'll use in a few minutes.

Pass this BooleanFilter - the one from ORM, since we're using the Doctrine ORM - because we want to allow the user to filter on a boolean field.

The second thing you need top pass is properties set to an array of which fields or properties you want to use this filter on. Set this to isPublished:

166 lines | src/Entity/DragonTreasure.php
// ... lines 1 - 4
use ApiPlatform\Doctrine\Orm\Filter\BooleanFilter;
use ApiPlatform\Metadata\ApiFilter;
// ... lines 7 - 38
#[ApiFilter(BooleanFilter::class, properties: ['isPublished'])]
class DragonTreasure
{
// ... lines 42 - 164
}

Using the Filter in the Request

All right! Go back to the documentation and check out the GET collection endpoint. When we try this... there's a new isPublished field! First, just hit "Execute" without setting that. When we scroll all the way down, there we go! hydra:totalItems: 40. Now set isPublished to true and try it again.

Yes! We have hydra:totalItems: 16. It's alive! And check out how the filtering happens. It's dead simple via a query parameter: isPublished=true. Oh, and it gets cooler. Look at the response: we have hydra:view, which shows the pagination and now we also have a new hydra:search. Yea, API Platform actually documents this new way of searching right in the response. It's saying:

Hey, if you want, you can add a ?isPublished=true query parameter to filter these results.

Pretty stinking cool.

Adding Filters Directly Above Properties

Now, when you read about filters inside of the API Platform docs, they pretty much always show it above the class, like we have. But you can also put the filter above the property it relates to.

Watch: copy the ApiFilter line, remove it, and go down to $isPublished. Paste this above. And now, we don't need the properties option anymore... API Platform figures that out on its own:

166 lines | src/Entity/DragonTreasure.php
// ... lines 1 - 38
class DragonTreasure
{
// ... lines 41 - 68
#[ApiFilter(BooleanFilter::class)]
private bool $isPublished = false;
// ... lines 71 - 164
}

The result? The same as before. I won't try it, but if you peek at the collection endpoint, it still has the isPublished filter field.

SearchFilter: Filter by Text

What else can we do? Another really handy filter is SearchFilter. Let's make it possible to search by text on the name property. This looks almost the same: above $name, add ApiFilter. In this case we want SearchFilter: again, get the one for the ORM. This filter also accepts an option. You can see here that, in addition to properties, ApiFilter has an argument called strategy. That doesn't apply to all filters, but it does apply to this one. Set strategy to partial:

168 lines | src/Entity/DragonTreasure.php
// ... lines 1 - 5
use ApiPlatform\Doctrine\Orm\Filter\SearchFilter;
// ... lines 7 - 39
class DragonTreasure
{
// ... lines 42 - 48
#[ApiFilter(SearchFilter::class, strategy: 'partial')]
private ?string $name = null;
// ... lines 51 - 166
}

This will allow us to search on the name property for a partial match. It's a "fuzzy" search. Other strategies include exact, start and more.

Let's give it a shot! Refresh the docs page. And... now the collection endpoint has another filter box. Search for rare and hit Execute. Let's see, down here... yes! Apparently 15 of the results have rare somewhere in the name.

And again, this works by adding a simple ?name=rare to the URL.

Oh, let's also make the description field searchable:

169 lines | src/Entity/DragonTreasure.php
// ... lines 1 - 5
use ApiPlatform\Doctrine\Orm\Filter\SearchFilter;
// ... lines 7 - 39
class DragonTreasure
{
// ... lines 42 - 48
#[ApiFilter(SearchFilter::class, strategy: 'partial')]
private ?string $name = null;
// ... lines 51 - 53
#[ApiFilter(SearchFilter::class, strategy: 'partial')]
private ?string $description = null;
// ... lines 56 - 167
}

And now... that shows up in the API too!

The SearchFilter is easy to set up... but it's a fairly simple fuzzy search. If you want something more complex - like ElasticSearch - API Platform does support that. You can even create your own custom filters, which we'll do in a future tutorial.

Alrighty: next, let's see two more filters: one simple and one weird... A filter that, instead of hiding results, allows the API user to hide certain fields in the response.