.. _index-view-label:
View
====
This is essential part of any web application which allows you easily show data using html templates and layouts.
Installation
------------
Run the following to install this library:
.. code-block:: bash
$ composer require esase/tiny-view
Template
---------
Templates usually used for displaying a part of a page. It would be like, `a login page` or `list of users`, etc.
----------------
Template example
----------------
.. code-block:: php
[
['id' => 1, 'name' => 'Tester1'],
['id' => 2, 'name' => 'Tester2']
]],
'./users.phtml' // a template for the data
);
// render the template using passed variables
echo $view;
And the `HTML` template `(users.phtml)`:
.. code-block:: html
users as $user): ?>
-
id ?>: name ?>
**Note:** In `HTML` files you are free to use any :code:`PHP` methods and operators.
Read more about the alternative syntax which is convenient way for using in templates: https://www.php.net/manual/en/control-structures.alternative-syntax.php
Layout
------
Layouts work as wrappers for generated content. In our case we may wrap the rendered `users list` in a layout
(which may include js/css files, meta, etc).
Usually there is a one universal layout and many templates but it optional.
--------------
Layout example
--------------
.. code-block:: php
[
['id' => 1, 'name' => 'Tester1'],
['id' => 2, 'name' => 'Tester2']
]],
'./users.phtml', // a template for the data
'./layout/base.phtml' // a layout for wrapping the data
);
// render both template and layout
echo $view;
And the `HTML` layout `(base.phtml)`:
.. code-block:: html
My test site
content ?>
View helpers
------------
Some times it not enough only inject variables in `templates/layouts` or call inbuilt :code:`PHP` functions.
We need to call our own functions in the template context.
To make it real the :code:`View` uses the :ref:`Event manager `.
Generally speaking whenever you call an undefined method (which is not registered in the :code:`View` object)
The :code:`View` triggers an event which includes the invoked method's name and its parameters,
and there is should be a listener which is responsible for that method.
In example bellow we implement a simple helper for printing a random value.
--------------
Helper example
--------------
.. code-block:: php
function() { // register a new view helper service
return function(Event $event) {
// return a random value
$event->setData(rand());
}
}
])
);
// listen the any invocations of `$this->random()` in the View and call it from the service manager
$eventManager->subscribe('view.call.helper.random', 'ViewHelperRandom');
// init the View
$view = new View(['users' => [
['id' => 1, 'name' => 'Tester1'],
['id' => 2, 'name' => 'Tester2']
]],
'./users.phtml'
);
// register the event manager in the View
$view->setEventManager($eventManager);
// render the template using passed variables
echo $view;
The `HTML` template snippet:
.. code-block:: html
users as $user): ?>
-
random() ?>: name ?>