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.
Every function in JavaScript is actually a Function object.
Function objects created with the Function constructor are parsed when the
function is created. This is less efficient than declaring a function and
calling it within your code, because functions declared with the function
statement are parsed with the rest of the code.
All arguments passed to the function are treated as the names of the identifiers of the parameters in the function to be created, in the order in which they are passed.
Invoking the Function constructor as a function (without using the new
operator) has the same effect as invoking it as a constructor.
Function constructorThe following code creates a Function object that takes two arguments.
// Example can be run directly in your JavaScript console
// Create a function that takes two arguments and returns the sum of those
arguments
var adder = new Function("a", "b", "return a + b");
// Call the function
adder(2, 6);
// > 8
The arguments "a" and "b" are formal argument names that are used in the function body, "return a + b".
Applies the method of another object in the context of a different object (the calling object); arguments can be passed as an Array object.
You can assign a different this object when calling an existing function. this refers to the
current object, the calling object. With apply, you can write a method once and then inherit it
in another object, without having to rewrite the method for the new object.
apply is very similar to call, except for the type of arguments it supports. You can use an
arguments array instead of a named set of parameters. With apply, you can use an array literal, for
example, fun.apply(this, ['eat', 'bananas']), or an Array object, for example, fun.apply(this,
new Array('eat', 'bananas')).
You can also use arguments for the argsArray parameter. arguments is a local variable of a
function. It can be used for all unspecified arguments of the called object. Thus, you do not have
to know the arguments of the called object when you use the apply method. You can use arguments
to pass all the arguments to the called object. The called object is then responsible for handling
the arguments.
Since ECMAScript 5th Edition you can also use any kind of object which is array like, so in
practice this means it's going to have a property length and integer properties in the range
[0...length). As an example you can now use a NodeList or a own custom object like {'length': 2,
'0': 'eat', '1': 'bananas'}.
You can use apply to chain constructors for an object, similar to Java. In the following example,
the constructor for the Product object is defined with two parameters, name and value. Two
other functions Food and Toy invoke Product passing this and arguments. Product
initializes the properties name and price, both specialized functions define the category. In
this example, the arguments object is fully passed to the product constructor and corresponds to
the two defined parameters.
function Product(name, price) {
this.name = name;
this.price = price;
if (price < 0)
throw RangeError('Cannot create product "' + name + '" with a negative price');
return this;
}
function Food(name, price) {
Product.apply(this, arguments);
this.category = 'food';
}
Food.prototype = new Product();
function Toy(name, price) {
Product.apply(this, arguments);
this.category = 'toy';
}
Toy.prototype = new Product();
var cheese = new Food('feta', 5);
var fun = new Toy('robot', 40);
Clever usage of apply allows you to use built-ins functions for some tasks that otherwise
probably would have been written by looping over the array values. As an example here we are going
to use Math.max/Math.min to find out the maximum/minimum value in an array.
//min/max number in an array
var numbers = [5, 6, 2, 3, 7];
//using Math.min/Math.max apply
var max = Math.max.apply(null, numbers); // This about equal to Math.max(numbers[0], ...) or
// Math.max(5, 6, ..)
var min = Math.min.apply(null, numbers);
//vs. simple loop based algorithm
max = -Infinity, min = +Infinity;
for (var i = 0; i < numbers.length; i++) {
if (numbers[i] > max)
max = numbers[i];
if (numbers[i] < min)
min = numbers[i];
}
But beware: in using apply this way, you run the risk of exceeding the JavaScript engine's
argument length limit. The consequences of applying a function with too many arguments (think more
than tens of thousands of arguments) vary across engines, because the limit (indeed even the nature
of any excessively-large-stack behavior) is unspecified. Some engines will throw an exception. More
perniciously, others will arbitrarily limit the number of arguments actually passed to the applied
function. (To illustrate this latter case: if such an engine had a limit of four arguments [actual
limits are of course significantly higher], it would be as if the arguments 5, 6, 2, 3 had been
passed to apply in the examples above, rather than the full array.) If your value array might grow
into the tens of thousands, use a hybrid strategy: apply your function to chunks of the array at a
time:
function minOfArray(arr)
{
var min = Infinity;
var QUANTUM = 32768;
for (var i = 0, len = arr.length; i < len; i += QUANTUM)
{
var submin = Math.min.apply(null, numbers.slice(i, Math.min(i + QUANTUM, len)));
min = Math.min(submin, min);
}
return min;
}
var min = minOfArray([5, 6, 2, 3, 7]);
thisArg : Object
The value of this provided for the call to fun. Note that this may not be the actual value seen by the method: if the method is a function in non-strict mode code, null and undefined will be replaced with the global object, and primitive values will be boxed.
argsArray : Array
An array like object, specifying the arguments with which fun should be called, or null or undefined if no arguments should be provided to the function.
Returns what the function returns.
Creates a new function that, when called, has its this keyword set
to the provided value, with a given sequence of arguments preceding
any provided when the new function was called.
The bind() function creates a new function (a bound function) with
the same function body (internal Call attribute in ECMAScript 5
terms) as the function it is being called on (the bound function's
target function) with the this value bound to the first argument of
bind(), which cannot be overridden. bind() also accepts leading
default arguments to provide to the target function when the bound
function is called. A bound function may also be constructed using
the new operator: doing so acts as though the target function had
instead been constructed. The provided this value is ignored, while
prepended arguments are provided to the emulated function.
The simplest use of bind() is to make a function that, no matter
how it is called, is called with a particular this value. A common
mistake for new JavaScript programmers is to extract a method from
an object, then to later call that function and expect it to use
the original object as its this (e.g. by using that method in
callback-based code). Without special care, however, the original
object is usually lost. Creating a bound function from the
function, using the original object, neatly solves this problem:
var x = 9;
var module = {
x: 81,
getX: function() { return this.x; }
};
module.getX(); // 81
var getX = module.getX;
getX(); // 9, because in this case, "this" refers to the global object
// create a new function with 'this' bound to module
var boundGetX = getX.bind(module);
boundGetX(); // 81
The next simplest use of bind() is to make a function with
pre-specified initial arguments. These arguments (if any) follow
the provided this value and are then inserted at the start of the
arguments passed to the target function, followed by the arguments
passed to the bound function, whenever the bound function is
called.
function list() {
return Array.prototype.slice.call(arguments);
}
var list1 = list(1, 2, 3); // [1, 2, 3]
// Create a function with a preset leading argument
var leadingZeroList = list.bind(undefined, 37);
var list2 = leadingZeroList(); // [37]
var list3 = leadingZeroList(1, 2, 3); // [37, 1, 2, 3]
NOTE: This method is part of the ECMAScript 5 standard.
thisArg : Object
The value to be passed as the this
parameter to the target function when the bound function is
called. The value is ignored if the bound function is constructed
using the new operator.
args : Mixed... (optional)
Arguments to prepend to arguments provided to the bound function when invoking the target function.
The bound function.
Calls (executes) a method of another object in the context of a different object (the calling object); arguments can be passed as they are.
You can assign a different this object when calling an existing function. this refers to the
current object, the calling object.
With call, you can write a method once and then inherit it in another object, without having to
rewrite the method for the new object.
You can use call to chain constructors for an object, similar to Java. In the following example,
the constructor for the product object is defined with two parameters, name and value. Another
object, prod_dept, initializes its unique variable (dept) and calls the constructor for
product in its constructor to initialize the other variables.
function Product(name, price) {
this.name = name;
this.price = price;
if (price < 0)
throw RangeError('Cannot create product "' + name + '" with a negative price');
return this;
}
function Food(name, price) {
Product.call(this, name, price);
this.category = 'food';
}
Food.prototype = new Product();
function Toy(name, price) {
Product.call(this, name, price);
this.category = 'toy';
}
Toy.prototype = new Product();
var cheese = new Food('feta', 5);
var fun = new Toy('robot', 40);
In this purely constructed example, we create anonymous function and use call to invoke it on
every object in an array. The main purpose of the anonymous function here is to add a print
function to every object, which is able to print the right index of the object in the array.
Passing the object as this value was not strictly necessary, but is done for explanatory purpose.
var animals = [
{species: 'Lion', name: 'King'},
{species: 'Whale', name: 'Fail'}
];
for (var i = 0; i < animals.length; i++) {
(function (i) {
this.print = function () {
console.log('#' + i + ' ' + this.species + ': ' + this.name);
}
}).call(animals[i], i);
}
thisArg : Object
The value of this provided for the call to fun.Note that this may not be
the actual value seen by the method: if the method is a function in non-strict mode code, null
and undefined will be replaced with the global object, and primitive values will be boxed.
args : Object...
Arguments for the object.
Returns what the function returns.
Creates new Function object.
args : String...
Names to be used by the function as formal argument names. Each must be a
string that corresponds to a valid JavaScript identifier or a list of such
strings separated with a comma; for example "x", "theValue", or "a,b".
functionBody : String
A string containing the JavaScript statements comprising the function definition.
Returns a string representing the source code of the function. Overrides the
Object.toString method.
The Function object overrides the toString method of the Object object; it does
not inherit Object.toString. For Function objects, the toString method returns a string
representation of the object.
JavaScript calls the toString method automatically when a Function is to be represented as a
text value or when a Function is referred to in a string concatenation.
For Function objects, the built-in toString method decompiles the function back into the
JavaScript source that defines the function. This string includes the function keyword, the
argument list, curly braces, and function body.
The function as a string.
Cmd | Terms of Use