Zend Framework 2 Saving layout and template content in database - templates

Question

I want to save both layout and view template CONTENT in the database. Each view template will be associated to a layout_id. When a controller action loads, it will fetch the appropriate layout and view from database.
I've done fair amount of researching, looks like this hasn't been discussed before, at least not with ZF2. Not only I want different themes for the site, I also want version control on the design, user can work on a version of template, save it and when done publish the site. I've been looking into custom view strategy and renderer and could not find out how to piece everything together.
Please advice how to proceed with this problem. If there are any tutorials out there please let me know.

Answer 1

First, you have to decide your database structure. I would prefer a table where for each controller/action, depending on the version of the design, you have a file for the layout view, and another for the action view. I think it is a flexible way, since you can have for instance the same layout for all the controllers, but a a different view for the content of every action, or you can have a different layout for an specific controller.
It could be something like this.
CREATE TABLE `templates` (
`version` INT(5) NOT NULL,
`controller` VARCHAR(30) NOT NULL,
`action` VARCHAR(30) NOT NULL,
`layout_view` VARCHAR(30) DEFAULT NULL,
`action_view` VARCHAR(30) DEFAULT NULL,
PRIMARY KEY (`version`,`module`,`controller`,`action`)
)
remember that the template names has to be 'MODULE/CONTROLLER/ACTION' that is the format that the function ViewModel::setTemplate is expecting. So if in your Module Foo, you have the folder view, with a hierachy like this Foo/view/foo/controllerName/actionName.phtml in your database you should store: foo/controllerName/actionName
Then you have to set, somewhere in the config files, the current design version that has to be used. This version could be a different one in your local machine, and in the production server. For that, you leverage the /config/autoload/local.php that allows you to have different configuration in the different enviroments, just telling your git, subversion, or ftp, to ignore this file, so you can have a different one in every enviroment. Check this docs. It will be enough if you put something like this:
/config/autoload/local.php
return array(
'designVersion' => 1,
);
Then when the application loads, you have to check the current version of the design, and set the correct templates to be used. I would do it after the dispatch event, so the way would be to add a listener in the app bootstrarp. For that, in your main module (i.e. "App" or "Application" module), in the Module.php you overwrite the onBootstrap function, load the event manager, and add a callback to the MvcEvent::EVENT_DISPATCH event.
There, you can have access to the serviceManager, so you can retrieve your database adapter, also, you can know the current requested controller and action, the current viewmodel object, and from it, the action viewmodel. So you already have everything you need. So you can go like this:
public function onBootstrap(MvcEvent $e) {
//get the service manager
$sm = $e->getApplication ()->getServiceManager ();
//get your db adapter
$db=$sm->get("whatever is the service name of your database adapter, entity manager, or whatever you are using");
//get the config
$config = $sm->get ( 'config' );
$version = $config ['designVersion'];
//get the event manager, and attach a callback to the MvcEvent::EVENT_DISPATCH
$em = $e->getApplication ()->getEventManager ();
$em->attach ( MvcEvent::EVENT_DISPATCH, function ($e) use($sm) {
//you get the routeMath, so you can know the controller and action
$routeMatch = $e->getRouteMatch ();
$action=$routeMatch->getParam ( 'action' );
$controller=$routeMatch->getParam ( 'controller' );
//now, with $action, $controller, and $version
//you query your db to get the layout and view templates:
$views=$db->whetever..
$layout_template= $views->layout_view;
$action_template= $views->action_view;
//you get the current viewModel, it hasnt been rendered yet, so we can set the templates
$viewModel = $e->getViewModel ();
if (is_null ( $viewModel ))
return;
$viewModel->setTemplate ($layout_template);
//and now, we get the action view model, that we know that is set as a children of the layout viewmodel. So we can retrieve it like this:
$children = $viewModel->getCurrent()->getChildren();
$child = $children[0];
//if we are afraid the view could have more children, and you want to make sure that you rerieve the correct one, then you could iterate over $children and look for the child that has the correct captureTo name set. For the action’s view model, this defaults to content:
/*
$children = $viewModel->getCurrent()->getChildren();
$child=null;
foreach($children as $c) {
if ($c->captureTo() == 'content') {
$child=$c;
break;
}
}
*/
//and now, you set the template to the view:
$child->setTemplate ($action_template);
}, - 100 );
}