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Introduction

Easy to use view engine with complexity hiding for view plugins.

Installation

Via composer:

composer require merophp/view-engine

Basic Usage

To use the view engine you have to create or use external view plugins.

Example:

require_once 'vendor/autoload.php';

use MyPackage\HtmlPlugin\HtmlView;
use MyPackage\TextPlugin\TextView;
use MyPackage\JsonPlugin\JsonView;
use MyPackage\TemplatePlugin\TemplateView;
use MyPackage\TemplatePlugin\TemplateViewConfiguration;

use Merophp\ViewEngine\ViewEngine;
use Merophp\ViewEngine\ViewPlugin\Collection\ViewPluginCollection;
use Merophp\ViewEngine\ViewPlugin\Provider\ViewPluginProvider;
use Merophp\ViewEngine\ViewPlugin\ViewPlugin;

$templateViewConfiguration = new TemplateViewConfiguration();
$templateViewConfiguration->setViewDir('.');

$collection = new ViewPluginCollection();
$collection->addMultiple([
    new ViewPlugin(TextView::class),
    new ViewPlugin(HtmlView::class),
    new ViewPlugin(JsonView::class),
    new ViewPlugin(TemplateView::class, $templateViewConfiguration)
]);

$provider = new ViewPluginProvider($collection);

$viewEngine = new ViewEngine($provider);

$view = $viewEngine->initializeView();
$view->json(['test' => 1]);
echo $viewEngine->renderView($view);

View Proxy

The view engine uses a proxy for view classes. The specialty is that you get a view proxy instance without a real view by calling $viewEngine->initializeView(). The view to wrap will be determined by the next called method.

For Example:

$view = $viewEngine->initializeView();
echo $view->getViewType(); //Will print 'undefined'
$view->json(['test' => 1]);
echo $view->getViewType(); //Will print 'Json'
echo $viewEngine->renderView($view);

Once determined the view type can not be changed for that instance.

View Plugins

A view plugin consists at minimum of a view class that implements Merophp\ViewEngine\ViewPlugin\ViewInterface and has at least one public non-magic & non-static method tagged with i>@api

use Merophp\ViewEngine\ViewPlugin\ViewInterface;

class DummyView implements ViewInterface{

    public function render(): string
    {
        return 'test';
    }

    /**
     * Method calls are forwarded by the view proxy
     * @param $value
     * @api
     */
    public function dummy($value)
    {
        return 'foo';
    }

    /**
     * Method calls are not forwarded by the view proxy due to their static type 
     * @param $value
     * @api
     */
    public static function dummy2($value)
    {
        echo 'foo';
    }

    public function getContentType(): string
    {
        return '';
    }
}

The Aim

The aim is to use the view engine as part of a framework to simplify the creation of views for the framework users. So you can provide an empty view proxy instance inside a controller action so the user can choose between some view types by calling methods on the proxy instance.

Be Aware of the Cons

Cause of the mechanic it isn't possible to use IDE functionality such as auto-fill or interface hints. In some cases, it also can be a little confusing cause of the dynamic interface of the proxy. As a framework developer using this library, you should document the possible view interfaces of the proxy well.