Simple Custom GET Action

Let's add a totally custom action. What if, when we're on the detail page for a question, we add a new action called "view" that takes us to the frontend for that question? Sounds good! Start in QuestionCrudController. To add a new action... we'll probably need to do some work inside of configureActions(). We already know how to add actions to different pages: with the ->add() method. Let's try adding, to Crud::PAGE_DETAIL, a new action called view.

Adding the Custom Action in configureActions()

There are a bunch of built-in action names - like index or delete - and we usually reference those via their Action constant. But in this case, we're making a new action... so let's just "invent" a string called view... and see what happens.

Refresh and... what happened was... an error!

The "view" action is not a built-in action, so you can't
add or configure it via its name. Either refer to one of
the built-in actions or create a custom action called "view".

In the last chapters, we talked about how, behind-the-scenes, each action is actually an Action object. We don't really think about that most of the time... but when we create a custom action, we need to deal with this object directly.

Above the return, create an Action object with $viewAction = Action::new()... and pass this the action name that we just invented: view. Then, below, instead of the string, this argument accepts an $actionNameOrObject. Pass in that new $viewAction variable.

Setting the Action to redirect

Refresh again to see... another error:

Actions must link to either a route, a CRUD action, or a URL.

And then it gives us three different methods we can use to set that up. That's a pretty great error message. It sounds like linkToRoute() or linkToUrl() is what we need.

So, up here, let's modify our action. We could use ->linkToRoute()... but as we learned earlier, that would generate a URL through the admin section, complete with all the admin query parameters. Not what we want. Instead, use ->linkToUrl().

But, hmm. We can't use $this->generateUrl() yet... because we need to know which Question we're generating the URL for. And we don't have that! Fortunately, the argument accepts a string or callable. Let's try that: pass a function()... and then to see what arguments this receives, let's use a trick: dd(func_get_args()).

Back in the browser... awesome! We are apparently passed one argument, which is the Question object. We're dangerous! Use that: return $this->generateUrl(), passing the frontend route name: which is app_question_show. This route has a slug route wildcard... so add the Question $question argument to the function and set slug to $question->getSlug().

Testing time! And now... yes! We have a "View" button. If we click it... it works!

Customizing How the Action Looks

And just like any other action, we can modify how this looks. Let's ->addCssClass('btn btn-success'), ->setIcon('fa fa-eye), and ->setLabel('View on site'): all things that we've done before for other actions.

Refresh and... that looks great! If we want to include this action on other pages, we can. Because, if you go to the index page, there's no "view on frontend" action. Thankfully, we created this nice $viewAction variable, so, at the bottom, we can reuse it: ->add(Crud::PAGE_INDEX, $viewAction).

Refresh and... got it! Though... you can see the btn styling doesn't really work well here. I won't do it, but you could clone the Action object and then customize each one.

$viewAction = function() {
    return Action::new('view')
        ->linkToUrl(function(Question $question) {
            return $this->generateUrl('app_question_show', [
                'slug' => $question->getSlug(),
            ]);
        })
        ->setIcon('fa fa-eye')
        ->setLabel('View on site');
};

// ...

return parent::configureActions($actions)
    // ...
    ->add(Crud::PAGE_DETAIL, $viewAction()->addCssClass('btn btn-success'))
    ->add(Crud::PAGE_INDEX, $viewAction());

Okay, so creating an action that links somewhere is cool. But what about a true custom action that connects to a custom controller with custom logic... that does custom... stuff? Let's add a custom action that allows moderators to approve questions, next.