Laravel Nova - How to determine the view (index, detail, form) you are in for a resource's computed field?

问题

I would like to return a different result for a computed field when viewing the index view than when viewing the detail view of a resource.

Basically something like viewIs() below:

Text::make('Preview', function () {
    if($this->viewIs('index'){
        return \small_preview($this->image);
    }
    return \large_preview($this->image);
 })->asHtml(),

回答1:

You can check the class of the request:

Text::make('Preview', function () use ($request) {
    if ($request instanceof \Laravel\Nova\Http\Requests\ResourceDetailRequest) {
        return \large_preview($this->image);
    }

    return \small_preview($this->image);
});

Otherwise, you can create your own viewIs function:

// app/Nova/Resource.php

/**
 * Check the current view.
 *
 * @param  string  $view
 * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
 * @retrun bool
 */
public function viewIs($view, $request)
{
    $class = '\Laravel\Nova\Http\Requests\\Resource'.ucfirst($view).'Request';

    return $request instanceof $class;
}

Then you can do it like this:

Text::make('Preview', function () use ($request) {
    if ($this->viewIs('detail', $request) {
        return \large_preview($this->image);
    }

    return \small_preview($this->image);
});

回答2:

The NovaRequest class will soon be able to help, as the isResourceIndexRequest and isResourceDetailRequest are already in master.

As the Nova repo is private I will keep you posted, when it will be usable.

In the meantime I am falling back to helper methods on the Nova Resource class (app/Nova/Resource.php):

namespace App\Nova;

use Laravel\Nova\Http\Requests\ResourceDetailRequest;
use Laravel\Nova\Http\Requests\ResourceIndexRequest;
use Laravel\Nova\Resource as NovaResource;
use Laravel\Nova\Http\Requests\NovaRequest;

abstract class Resource extends NovaResource
{
    // [...]

    /**
     * Determine if this request is a resource index request.
     *
     * @return bool
     */
    public function isResourceIndexRequest($request)
    {
        return $request instanceof ResourceIndexRequest;
    }

    /**
     * Determine if this request is a resource detail request.
     *
     * @return bool
     */
    public function isResourceDetailRequest($request)
    {
        return $request instanceof ResourceDetailRequest;
    }
}

Usage:

public function fields(Request $request)
{
    $fields = [
        // [...]
    ];

    if ($this->isResourceDetailRequest($request)) {
        if ($this->isResourceDetailRequest($request)) {
            $fields = array_merge($fields, [
                // [...]
            ]);
        }
    }

    return $fields;
}

回答3:

You can create two separate fields for index & details page.

// ----- For Index page
Text::make('Preview', function () {
    return \small_preview($this->image);
})
->onlyOnIndex()
->asHtml(),

// ----- For Detail page
Text::make('Preview', function () {
    return \large_preview($this->image);
})
->onlyOnDetail()
->asHtml(),

回答4:

Unfortunately, @Chin's answer did not work for me as for Edit view the request class is just a basic Laravel\Nova\Http\Request class.

My workaround to check if this is an index view is as follows:

/**
 * Check if the current view is an index view.
 *
 * @param  \Laravel\Nova\Http\Requests\NovaRequest $request
 * @return bool
 */
public function isIndex($request)
{
    return $request->resourceId === null;
}

来源：https://stackoverflow.com/questions/53703555/laravel-nova-how-to-determine-the-view-index-detail-form-you-are-in-for-a

标签

laravel-nova

computed-field