Laravel 8 Livewire use variable data from render in other method

Question

In my Laravel 8 Jetstream installation based on livewire, I have a component that lists some records.

These records can be filtered on the front-end based on some criterias in real time with live update and paginated.

Nothing special yet and everything works as expected.

Now, I need to implement an export() method that will export the filtered data and I don't know how or not even sure if it's possible to access the data variables from the render() method so I can use only the filtered data for the export.

Pages component

public $type;
public $color;

public function export() {
    $dataToExport = 'here I need the filtered data from $pages variables from render method so I can export them';
}

public function render() {
    $pages = Page::when($this->type, function($query) {
         $query->where('type', $this->type);
    })
    ->when($this->color, function($query) {
        $query->where('color', $this->color);
    })
    ...
    ->paginate();

    return view('livewire.page.index', [
        'pages' => $pages
    ]);
}

I'm using the render() method to prepare the data by querying the database because it renders and outputs the correct data when I change something on the front-end.

Basically, everything works fine, but on the front-end I have a button that will trigger the export method, so the filtered data must be available for the method to be exported.

I also choose this approach because I think it's safer not to expose the data in a public property. Maybe I'm not using the best approach for this, so I'm open to a better solution that takes care of performance and security as well.

BTW: What's the difference (in terms of security and/or performace) of using variables within render() method, or using properties?

Answer 1

There'll be no significant difference in term of performance or security using the data on the render or on a public property, both approach will expose the data to the javascript. If you're dealing with sensitive data I wouldn't recommend to use Livewire.

From your code, I think you can get the same query using a function:

public $type;
public $color;

public function export() {
    $dataToExport = $this->pages()->someWayOfExportTheFilteredData();
}

public function render() {
    return view('livewire.page.index', [
        'pages' => $this->pages()->paginate()
    ]);
}

protected function pages()
{
    return Page::when($this->type, function($query) {
         $query->where('type', $this->type);
    })
    ->when($this->color, function($query) {
        $query->where('color', $this->color);
    })
    ...
}