Sharp Context

Sharp provide a way to grab some request context values in the application code.

Generalities

The class handling the context is Code16\Sharp\Http\Context\SharpContext; at any point in the request, you can get it via the global helper:

sharp()->context();

Current context

Let's start with a simple example of how to use the context in a Form to set a field as read-only when the form is in update mode:

class MyForm extends SharpForm
{
    // ...
    
    function buildFormFields()
    {
        $this
            ->addField(
                SharpFormTextField::make('key')
                    ->setReadOnly(sharp()->context()->isUpdate())
            )
            ->addField(/*...*/);
    }
}

The SharpContext class allows you to get the following information:

entityKey

Grab the current entity key.

isEntityList

isShow

isForm

Find out the current page type.

isUpdate

isCreation

In Form case, check the current status.

instanceId

In Form and Show Page cases, grab the instance id.

Interact with Sharp's Breadcrumb

To interact with Sharp's breadcrumb, you can call:

sharp()->context()->breadcrumb();

... and then use the following methods:

currentSegment

previousSegment

Get the current or previous breadcrumb item.

previousShowSegment

previousListSegment

Get (if existing) the closest Show or List in the breadcrumb.

TIP

As always, prefer the entity class name to the entity key. For instance: sharp()-⁠>context()-⁠>breadcrumb()-⁠>previousShowSegment(MyEntity::class).

The BreadcrumbItem class

A BreadcrumbItem instance has most of the methods seen above (note: no isUpdate()/isCreation() here, since a breadcrumb segment doesn't carry that information):

entityKey

isEntityList

isShow

isSingleShow

isForm

isSingleForm

instanceId

entityIs

Here's an example of how this information could be useful: imagine you have a Show for a Post instance, with an Embedded Entity List of Comment. When creating a new Comment, you'll need to set its post_id attribute on the Form update() method. You can for this make use of the breadcrumb context like this:

class CommentForm extends SharpForm
{
    // ...
    
    function update($id, array $data)
    {
        $comment = $id 
            ? Comment::find($id) 
            : new Comment([
                'post_id' => sharp()->context()
                    ->breadcrumb()
                    ->previousShowSegment(PostEntity::class)
                    ->instanceId()
            ]);

        $this->save($comment, $data);
        
        return $comment->id;
    }
}

Global and retained filters

globalFilterValue

Get the value of a Global Filter: see the Global Filter documentation to know more about this feature.

retainedFilterValue

Get the value of a retained Filter: see the Retained Filter documentation to know more about this feature.

Access instances cached by an Entity List

This feature is really useful to avoid multiple queries on the same instance in a single request. The specific documentation is available here.