Dependencies and MVC
Many classes have shortcut names used when creating (instantiating) a class with a
configuration object. The shortcut name is referred to as an alias (or xtype if the
class extends Ext.Component). The alias/xtype is listed next to the class name of
applicable classes for quick reference.
Framework classes or their members may be specified as private or protected. Else,
the class / member is public. Public, protected, and private are access
descriptors used to convey how and when the class or class member should be used.
Public classes and class members are available for use by any other class or application code and may be relied upon as a stable and persistent within major product versions. Public classes and members may safely be extended via a subclass.
Protected class members are stable public members intended to be used by the
owning class or its subclasses. Protected members may safely be extended via a subclass.
Private classes and class members are used internally by the framework and are not intended to be used by application developers. Private classes and members may change or be omitted from the framework at any time without notice and should not be relied upon in application logic.
static label next to the
method name. *See Static below.Below is an example class member that we can disect to show the syntax of a class member (the lookupComponent method as viewed from the Ext.button.Button class in this case).
Let's look at each part of the member row:
lookupComponent in this example)( item ) in this example)Ext.Component in this case). This may be omitted for methods that do not
return anything other than undefined or may display as multiple possible values
separated by a forward slash / signifying that what is returned may depend on the
results of the method call (i.e. a method may return a Component if a get method calls is
successful or false if unsuccessful which would be displayed as
Ext.Component/Boolean).PROTECTED in
this example - see the Flags section below)Ext.container.Container in this example). The source
class will be displayed as a blue link if the member originates from the current class
and gray if it is inherited from an ancestor or mixed-in class.view source in the example)item : Object in the example).undefined a "Returns" section
will note the type of class or object returned and a description (Ext.Component in the
example)Available since 3.4.0 - not pictured in
the example) just after the member descriptionDefaults to: false)The API documentation uses a number of flags to further commnicate the class member's function and intent. The label may be represented by a text label, an abbreviation, or an icon.
classInstance.method1().method2().etc();false is returned from
an event handler- Indicates a framework class
- A singleton framework class. *See the singleton flag for more information
- A component-type framework class (any class within the Ext JS framework that extends Ext.Component)
- Indicates that the class, member, or guide is new in the currently viewed version
- Indicates a class member of type config
- Indicates a class member of type property
- Indicates a class member of type
method
- Indicates a class member of type event
- Indicates a class member of type
theme variable
- Indicates a class member of type
theme mixin
- Indicates that the class, member, or guide is new in the currently viewed version
Just below the class name on an API doc page is a row of buttons corresponding to the types of members owned by the current class. Each button shows a count of members by type (this count is updated as filters are applied). Clicking the button will navigate you to that member section. Hovering over the member-type button will reveal a popup menu of all members of that type for quick navigation.
Getting and setter methods that correlate to a class config option will show up in the methods section as well as in the configs section of both the API doc and the member-type menus just beneath the config they work with. The getter and setter method documentation will be found in the config row for easy reference.
Your page history is kept in localstorage and displayed (using the available real estate) just below the top title bar. By default, the only search results shown are the pages matching the product / version you're currently viewing. You can expand what is displayed by clicking on the button on the right-hand side of the history bar and choosing the "All" radio option. This will show all recent pages in the history bar for all products / versions.
Within the history config menu you will also see a listing of your recent page visits. The results are filtered by the "Current Product / Version" and "All" radio options. Clicking on the button will clear the history bar as well as the history kept in local storage.
If "All" is selected in the history config menu the checkbox option for "Show product details in the history bar" will be enabled. When checked, the product/version for each historic page will show alongside the page name in the history bar. Hovering the cursor over the page names in the history bar will also show the product/version as a tooltip.
Both API docs and guides can be searched for using the search field at the top of the page.
On API doc pages there is also a filter input field that filters the member rows using the filter string. In addition to filtering by string you can filter the class members by access level, inheritance, and read only. This is done using the checkboxes at the top of the page.
The checkbox at the bottom of the API class navigation tree filters the class list to include or exclude private classes.
Clicking on an empty search field will show your last 10 searches for quick navigation.
Each API doc page (with the exception of Javascript primitives pages) has a menu view of metadata relating to that class. This metadata view will have one or more of the following:
Ext.button.Button class has an alternate class name of Ext.Button). Alternate class
names are commonly maintained for backward compatibility.Runnable examples (Fiddles) are expanded on a page by default. You can collapse and expand example code blocks individually using the arrow on the top-left of the code block. You can also toggle the collapse state of all examples using the toggle button on the top-right of the page. The toggle-all state will be remembered between page loads.
Class members are collapsed on a page by default. You can expand and collapse members using the arrow icon on the left of the member row or globally using the expand / collapse all toggle button top-right.
Viewing the docs on narrower screens or browsers will result in a view optimized for a smaller form factor. The primary differences between the desktop and "mobile" view are:
The class source can be viewed by clicking on the class name at the top of an API doc page. The source for class members can be viewed by clicking on the "view source" link on the right-hand side of the member row.
There are two main places that dependencies can be defined in a Sencha Touch app - on the application itself or inside the application classes. This guide gives some advice on how and where to declare dependencies in your app.
When you create an MVC application, your Ext.application gives you a convenient way of specifying the models, views, controllers, stores and profiles that your application uses. Here's an example:
Ext.application({
name: 'MyApp',
views: ['Login'],
models: ['User'],
controllers: ['Users'],
stores: ['Products'],
profiles: ['Phone', 'Tablet']
});
These five configuration options are convenient ways to load the types of files that applications usually consist of - models, views, controllers, stores, and profiles. Specifying these configurations means your application will automatically load the following files:
In terms of entities that get loaded, the example above is equivalent to manually defining dependencies like this:
Ext.require([
'MyApp.view.Login',
'MyApp.model.User',
'MyApp.controller.Users',
'MyApp.store.Products',
'MyApp.profile.Phone',
'MyApp.profile.Tablet'
]);
As you add more classes to your application, these configurations become more and more useful in helping you avoid typing out the full class names for every file. Be aware, however, that three of those configurations do more than just load files--they also do the following:
This means that if you want to take advantage of all of the convenience MVC offers you,
use these configuration options when defining your application dependencies.
When using Device Profiles, chances are that you have some classes that are used only on certain devices. For example, the Tablet version of your app probably contains more functionality than the Phone version, which usually means it ill needs to load more classes. Additional dependencies can be specified inside each Profile:
Ext.define('MyApp.profile.Tablet', {
extend: 'Ext.app.Profile',
config: {
views: ['SpecialView'],
controllers: ['Main'],
models: ['MyApp.model.SuperUser']
},
isActive: function() {
return Ext.os.is.Tablet;
}
});
The dependencies specified in each Profile are loaded regardless of whether or not a Profile is active. The difference is that, even though they are loaded, the Application does not know how to do the additional processing, such as instantiating profile-specific Controllers if the profile is not active.
This probably sounds counter-intuitive - why download classes that are not going to be used? The reason we do this is to produce a universal production build that can be deployed to any device, detect which profile it should use and then boot the app. The alternative is to create custom builds for each profile, create a micro-loader than can detect which profile a device should activate and then download the code for that profile.
While the universal build approach means that you are downloading code you do not need on every device, for the vast majority of apps this amounts to very little additional size.
For larger apps it is common to split the models, views, and controllers into subfolders so keep the project organized. This is especially true of views - since it is not uncommon for large apps to have over a hundred separate view classes, organizing them into folders can make maintenance much simpler.
To specify dependencies in subfolders use a period (".") to specify the folder:
Ext.application({
name: 'MyApp',
controllers: ['Users', 'nested.MyController'],
views: ['products.Show', 'products.Edit', 'user.Login']
});
In this case, the following five files load:
Note We can mix and match within each configuration here - for each model, view, controller, profile or store, you can specify either the final part of the class name (if you follow the directory conventions), or the full class name.
We can specify application dependencies from outside our application by fully-qualifying the classes we want to load. A common use case for this is sharing authentication logic between multiple applications. Perhaps you have several apps that login via a common user database and you want to share that code between them. An easy way to do this is to create a folder alongside your app folder and then add its contents as dependencies for your app.
For example, assuming that our shared login code contains a login controller, a user model, and a login form view, we want to use all of these in our application:
Ext.Loader.setPath({
'Auth': 'Auth'
});
Ext.application({
views: ['Auth.view.LoginForm', 'Welcome'],
controllers: ['Auth.controller.Sessions', 'Main'],
models: ['Auth.model.User']
});
This loads the following files:
The first three files load from outside our application, the last two from the application itself.
Notes
In this example, the Loader finds classes starting with the 'Auth' namespace inside our 'Auth' folder. We can drop our common Auth code into our application alongside the app folder, and the framework figures out how to load everything.
The general rule when deciding where to declare each dependency is to keep your classes completely self-contained. For example, if you have a view that contains several other views, you should declare those dependencies inside the view class, not the application:
Ext.define('MyApp.view.Main', {
extend: 'Ext.Container',
requires: [
'MyApp.view.Navigation',
'MyApp.view.MainList'
],
config: {
items: [
{
xtype: 'navigation'
},
{
xtype: 'mainlist'
}
]
}
});
You can then use the following code in your app.js:
Ext.application({
views: ['Main']
});
This is the best way to declare those dependencies for two reasons - it keeps your app.js clean and enables you to reliably require your MyApp.view.Main while knowing that it already has all of its dependencies satisfied. The alternative would be to list all of your views inside app.js like in the following example:
//this is bad
Ext.application({
views: ['Main', 'Navigation', 'MainList']
});
A simple way of thinking about this is that app.js only contains top-level views. If you use Ext.create('MyApp.view.SomeView') inside your app, that view can be considered top-level. Whenever a view is only constructed as a sub-view of another view (as with MyApp.view.Navigation and MyApp.view.MainList above), it does not belong in app.js.
In Sencha Touch 1.x, dependencies were often specified in Controllers, as well as in the Ext.application call. While this approach offered some conveniences, it also masked the true architecture of the system and coupled views, models, and stores too closely to controllers. The following sample shows code that was possible in 1.x:
//1.x code, deprecated
Ext.regController('SomeController', {
views: ['Login'],
models: ['User'],
stores: ['Products']
});
This is the same as defining the views, models, and stores inside Ext.application, but also gave some convenience methods for accessing those classes inside your controller. 1.x generated two functions - getLoginView() and getUserModel() - and exposed a getStore() function that returned a reference to any of the Stores defined in this Controller. In Sencha Touch, these functions no longer exist, but it is easy to use the alternatives.
In the following example the first line refers to Sencha Touch 1.x code, while the second line shows the 2.x way:
//creating a view - 2.x uses the standardized Ext.create
this.getLoginView().create();
Ext.create('MyApp.view.Login');
//getting a Model - just type out the Model name (it's shorter and faster)
this.getUserModel();
MyApp.model.User;
//Ext.getStore can access any Store whereas the old this.getStore only
//accessed those Stores listed in your Controller
this.getStore('Products');
Ext.getStore('Products');
Removing these functions speeds up application launching because the framework no longer needs to generate one function for each model and view defined in each Controller. It also means that the conventions for MVC match the conventions for the rest of the framework, which leads to a more predictable API.
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