Feature Request: Show block preview on hover menu

[luya-bot]

This issue has originally been reported by @dven84 at luyadev/luya-module-admin#120.
Moved here by @nadar.

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Like preview in file manager.

[boehsermoe]

Nice feature. What do think to add preview() function (like the admin()) which will generate the html. To scale the preview we could use transform: scale for zoom.

public function preview()
{
    // Example values for the preview
    $this->setVarValues([
        'var1' => 'Lorem ipsum',
        'var2' => 'Some other variable',
    ]);
    
    return $this->frontend();
}

[nadar]

This will only work if the block does not require the frontend from the css while running frontend(). Maybe it would be more easy to create a real screenshot when used in frontend with something like this: https://github.com/niklasvh/html2canvas

[boehsermoe]

You could add the css fromfrontend() and load it in a iframe. For the html2canvas I mean you need also a url where each block will rendered and then it will create a screenshot.
I think it will need to have a PreviewBlockController which will generate the html anyway. After this we still have this two options.

[nadar]

@boehsermoe yes i agree. How could we fill in the var/cfg values from config? How to handler placeholders?

[boehsermoe]

@nadar please take a look for luyadev/luya-module-admin#232 and #148. What do you think?