Controllers
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.
Controllers are responsible for responding to events that occur within your app. If your app contains a Logout button that your user can tap on, a Controller listens to the Button's tap event and takes the appropriate action. While View classes handles the display of data and Model classes handle the loading and saving of data, Controller classes are the glue that binds Views and Models together.
Controllers exist within the context of an Application. An Application usually consists of a number of Controllers, each of which handle a specific part of the app. For example, an Application that handles the orders for an online shopping site might have controllers for Orders, Customers, and Products.
All Controllers used by an Application are specified in the Application's controllers config. The Application automatically instantiates each Controller and keeps references to each of them, so in most cases you do not need to instantiate Controllers directly. By convention each Controller is named after the entity (usually the Model) that it manages, usually in the plural - for example, if your app is called 'MyApp' and you have a Controller that manages Products, the convention is to create a MyApp.controller.Products class in the file app/controller/Products.js.
There are four main phases in your Application's launch process, two of which pertain to a Controller. First, each Controller is able to define an init function, which is called before the Application launch function. Second, after the Application and Profile launch functions have been called, as the last phase of the process the Controller's launch function is called, as follows:
Most of the time your Controller-specific launch logic should go into your Controller's launch function. Because the controller's launch function is called after the Application and Profile launch functions, your app's initial UI is expected to be in place at this point. If you need to do some Controller-specific processing before app launch, you can implement a Controller init function.
The centerpiece of Controllers are the twin configurations refs and control. These are used to gain references to Components inside your app and to take action on them, based on the events that they fire. In the following sections we first look at the refs config.
Refs leverage the powerful ComponentQuery syntax to easily locate Components on your page. For each Controller we can define as many refs as required, for example in the following example we define a ref called 'nav' that finds on the page a Component with the 'mainNav' ID. We then use that refs in the subsequent addLogoutButton function, as shown in this sample:
Ext.define('MyApp.controller.Main', {
extend: 'Ext.app.Controller',
config: {
refs: {
nav: '#mainNav'
}
},
addLogoutButton: function() {
this.getNav().add({
text: 'Logout'
});
}
});
Usually, a ref is just a key/value pair - the key ('nav' in this case) is the name of the reference that is to be generated, while the value ('#mainNav' in this case) is the ComponentQuery selector used to find the Component.
We have then created the addLogoutButton function which uses this ref via its generated 'getNav' function. This getter function is automatically generated based on the refs you define and always follows the same format - 'get', followed by the capitalized ref name. In this case we are treating the nav reference as a Toolbar, and we add a Logout button to it when our function is called. This ref would recognize a Toolbar such as the following:
Ext.create('Ext.Toolbar', {
id: 'mainNav',
items: [
{
text: 'Some Button'
}
]
});
Assuming that this Toolbar has already been created by the time we run the 'addLogoutButton' function (we will see later how that is invoked), it will get the second button added to it.
Refs can also be passed additional options, beyond name and selector. These options are autoCreate and xtype, which are almost always used together:
Ext.define('MyApp.controller.Main', {
extend: 'Ext.app.Controller',
config: {
refs: {
nav: '#mainNav',
infoPanel: {
selector: 'tabpanel panel[name=fish] infopanel',
xtype: 'infopanel',
autoCreate: true
}
}
}
});
We have added a second ref to our Controller. Again the name is the key, 'infoPanel' in this case, but this time we have passed an object as the value. This time we have used a more complex selector query - imagine that your app contains a tab panel and that one of the items in the tab panel is named 'fish'. The previously specified selector matches any Component with the 'infopanel' xtype inside the tab panel item.
The difference here is that, if infopanel does not exist already inside the 'fish' panel, it will be automatically created when you run this.getInfoPanel inside your Controller. The Controller is able to create the infopanel Component because we provided the xtype for instantiating it, in case the selector did not return anything.
The related config to refs is control. Control is the means by which your Controller listens to events fired by app Components and reacts in some way. The Control config accepts both ComponentQuery selectors and refs as its keys, and listener objects as values, as shown in the following example:
Ext.define('MyApp.controller.Main', {
extend: 'Ext.app.Controller',
config: {
control: {
loginButton: {
tap: 'doLogin'
},
'button[action=logout]': {
tap: 'doLogout'
}
},
refs: {
loginButton: 'button[action=login]'
}
},
doLogin: function() {
// called whenever the Login button is tapped
},
doLogout: function() {
// called whenever any Button with action=logout is tapped
}
});
In the previous example we have set up two control declarations - one for the loginButton ref and the other for any Button that has been given the 'logout' action. For each declaration we passed in a single event handler - in each case listening for the 'tap' event - and specified the action that should be called when that Button fires the tap event. Note that we specified both the 'doLogin' and 'doLogout' methods as strings inside the control block - this is important.
In each control declaration, you can listen to as many events as you like, and mix and match ComponentQuery selectors and refs as the keys.
As of Sencha Touch, Controllers can directly specify which routes they are interested in. This enables us to provide history support within our app, as well as the ability to deeply link to any part of the application that we provide a route for.
For example, let us assume that we have a Controller responsible for logging in and viewing user profiles, and want to make those screens accessible via urls. We could achieve that as follows:
Ext.define('MyApp.controller.Users', {
extend: 'Ext.app.Controller',
config: {
routes: {
'login': 'showLogin',
'user/:id': 'showUserById'
},
refs: {
main: '#mainTabPanel'
}
},
// uses our 'main' ref above to add a loginpanel to our main TabPanel (note that
// 'loginpanel' is a custom xtype created for this application)
showLogin: function() {
this.getMain().add({
xtype: 'loginpanel'
});
},
// Loads the User then adds a 'userprofile' view to the main TabPanel
showUserById: function(id) {
MyApp.model.User.load(id, {
scope: this,
success: function(user) {
this.getMain().add({
xtype: 'userprofile',
user: user
});
}
});
}
});
The routes specified previously map the contents of the browser address bar to a Controller function that is called when the route is matched. The routes can be simple text like the login route, which matches against http://myapp.com/#login, or may contain wildcards such as the 'user/:id' route, which matches urls like http://myapp.com/#user/123. Whenever the address changes, the Controller automatically calls the specified function.
Note that the showUserById function first has to load the User instance. Whenever you use a route, the function that is called by that route is completely responsible for loading its data and restoring the state. This is because a user could either send that url to another person or could simply refresh the page, which wipes any cached data that you had already loaded. In the application architecture guides you can find a more thorough discussion on restoring state with routes.
An additional functionality that Controllers provide within the context of Routing is the ability to define filter functions that are run before the function specified in the route. These are an excellent place to authenticate or authorize users for specific actions, or to load classes that are not yet on the page. For example, let us say we want to authenticate a user before allowing him to edit a Product in an e-commerce backend application:
Ext.define('MyApp.controller.Products', {
config: {
before: {
editProduct: 'authenticate'
},
routes: {
'product/edit/:id': 'editProduct'
}
},
// this is not directly because our before filter is called first
editProduct: function() {
//... performs the product editing logic
},
// this is run before editProduct
authenticate: function(action) {
MyApp.authenticate({
success: function() {
action.resume();
},
failure: function() {
Ext.Msg.alert('Not Logged In', "You can't do that, you're not logged in");
}
});
}
});
Whenever the user navigates to an URL such as http://myapp.com/#product/edit/123, the Controller's authenticate function is called and is passed the Ext.app.Action that would have been executed if the before filter did not exist. An Action simply represents the Controller function (editProduct in this case) and other data, such as the ID parsed from the url.
The filter can perform any kind of processing it needs to, either synchronously or asynchronously. In this case we are using our application's authenticate function to verify that the user is currently logged in. Since this could entail an AJAX request to check the user's credentials on the server, it runs asynchronously - if the authentication was successful, we continue the action by calling action.resume(), if not we tell the user that he needs to log in first.
Before filters can also be used to load additional classes before certain actions are performed. For example, if some actions are rarely used, you may wish to defer loading of their source code until they are needed, so that the application boots up faster. To achieve this you can simply set up a filter that uses Ext.Loader to load code on demand.
Any number of before filters can be specified for each action, to use more than one filter simply pass in an array:
Ext.define('MyApp.controller.Products', {
config: {
before: {
editProduct: ['authenticate', 'ensureLoaded']
},
routes: {
'product/edit/:id': 'editProduct'
}
},
// this is not directly because our before filter is called first
editProduct: function() {
//... performs the product editing logic
},
// this is the first filter that is called
authenticate: function(action) {
MyApp.authenticate({
success: function() {
action.resume();
},
failure: function() {
Ext.Msg.alert('Not Logged In', "You can't do that, you're not logged in");
}
});
},
// this is the second filter that is called
ensureLoaded: function(action) {
Ext.require(['MyApp.custom.Class', 'MyApp.another.Class'], function() {
action.resume();
});
}
});
The filters are called in order, and each must call action.resume() to continue the processing.
Superclass, shared stuff:
Ext.define('MyApp.controller.Users', {
extend: 'Ext.app.Controller',
config: {
routes: {
'login': 'showLogin'
},
refs: {
loginPanel: {
selector: 'loginpanel',
xtype: 'loginpanel',
autoCreate: true
}
},
control: {
'logoutbutton': {
tap: 'logout'
}
}
},
logout: function() {
// code to close the user's session
}
});
Phone Controller:
Ext.define('MyApp.controller.phone.Users', {
extend: 'MypApp.controller.Users',
config: {
refs: {
nav: '#mainNav'
}
},
showLogin: function() {
this.getNav().setActiveItem(this.getLoginPanel());
}
});
Tablet Controller:
Ext.define('MyApp.controller.tablet.Users', {
extend: 'MyApp.controller.Users',
showLogin: function() {
this.getLoginPanel().show();
}
});
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