SPApp
Single Page Application Micro Framework
Supports views, controllers and routing in 60 lines of code!
Introduction
If you heard anything about MVC in web applications, in particular words like "views", "controllers", "routing" and don't feel that you need more than jQuery in your project then this small library is for you.
Structure of your SPApp
Let's consider structure of simple "contact list" web application:
<script type="text/javascript" src="spapp.js"></script>
<body>
<nav>
<a href="#contact-list">Contacts</a>
<a href="#about">About</a>
</nav>
<section id="contact-list" src="pages/contact-list.htm" default></section>
<section id="contact-details" src="pages/contact-details.htm"></section>
<section id="about" src="pages/about.htm"></section>
</body>
We have <nav>
igation section here and collection of <section>
s - views that need to be presented when user clicks
on one of hyperlinks in the nav bar (or anywhere else). Also, if you want to load a section by default, simply add the default
attribute.
Routing
By definig <section id="some id">
element in your markup you actually define a route. When browser is navigated to
{url of your app}#id-of-section
the SPApp module catches this event and shows <section>
with that ID.
No special mechanism for declaring routes is required - simply declare <section>
s with proper IDs.
Views and Controllers
Notice that each <section>
above has src={url}
attribute declared. That URL points to partial HTML fragment
that defines content of the view and its controller function.
Typical structure of a view looks like this:
<h2>Contact Details</h2>
<label>First name</label> <input name="firstName">
<label>Last name</label> <input name="lastName">
...
<script>
window.app.page("contact-details", function()
{
var $firstName = $(this).find('[name="firstName"]');
var $lastName = $(this).find('[name="lastName"]');
...
return function(params) {
var contactId = params;
contact = contacts[contactId];
$firstName.val(contact.firstName);
$lastName.val(contact.lastName);
...
}
});
</script>
As you see markup above contains two sections:
- html markup of the view per se and
- script block with
app.page("{name}",scopeInitializerAndController )
function.
The scopeInitializerAndController function above serves two tasks:
-
initilizes the view and its scope variables and
-
returns function (a.k.a. "controller"). That function will be called each time the view needs to be presented/rendered.
Switching views and passing parameters
The application can be switched to show different views in one of these ways:
- By user navigating browser to
{your app url}#name-of-the-view:optional-parameter
; - By user clicking on
<a href="#name-of-the-view:optional-parameter">
hyperlinks on app page; - By code, calling
window.app("name-of-the-view", parameters)
function.
In all cases the SPApp framework will call controller registered for the view passing given parameter to it.
View events
While switching the view the SPAapp will trigger two events:
- "page.hidden" with
event.target
set on <section>
to be "closed" and - "page.shown" with
event.target
set on <section>
to be "shown".
So by subscribing on these events any code inside or outside controllers can receive notification about application state change.
Styling application and view states.
When the application navigates to particular view defined in <section id="view-a">
it is said that it is in "view-a" state. SPApp marks this state by assigning "view-a" class to the <body>
element in your document. Having this you can define view visibility rules in your CSS:
body > section { display:none; }
body.view-a > section#view-a,
body.view-b > section#view-b,
body.view-c > section#view-c { display:block; }
Note that switching the view into different states may require not only to hide/show some sections but also
to style some other indicators like nav-bar items highlighting:
body.view-a > nav > a[href="#view-a"],
body.view-b > nav > a[href="#view-b"],
body.view-c > nav > a[href="#view-c"] { background:white; color:black; }
Wrapping up
It is not strictly required for controller's code to be placed inside the view markup, you can put them in separate script files and include as any other scripts:
<script type="text/javascript" src="controller-a.js"></script>
<script type="text/javascript" src="controller-b.js"></script>
...
The only thing that required is that scopeInitializerAndControoler function must be registered by calling
window.app.page("view-a", function()
{
... initialization ...
return function(params) {
... presentation ...
}
});
In the same way markup for views can be provided inline without use of external files:
<section id="view-a" >
... markup of view-a ...
</section>
<section id="view-b" >
... markup of view-b ...
</section>
#Live Demo
Check this SPApp in action demo. I've created it in explicitly simple and minimalistic fashion in order to highlight just SPAapp. I have projects where it works in Twitter Bootstrap environment for example.