Table of contents
METHOD |
RETURN |
DESCRIPTION |
---|---|---|
instance
|
Clones objects (including DOM nodes) and all children |
|
any
|
Returns a new object which “looks” to obj for properties which it does not have a value for |
|
boolean
|
determine if an object supports a given method |
|
object
|
Adds all properties and methods of props to constructor’s prototype, making them available to all instances created with constructor |
|
any
|
Get a property from a dot-separated string, such as “A |
|
function
|
Returns a function that will only ever execute in the given scope |
|
boolean
|
Return true if it is an Array |
|
boolean
|
similar to isArray() but more permissive |
|
boolean
|
Return true if it is a Function |
|
boolean
|
Returns true if it is a JavaScript object (or an Array, a Function or null) |
|
boolean
|
Return true if it is a String |
|
object
|
Copies/adds all properties of one or more sources to dest; returns dest |
|
Similar to hitch() except that the scope object is left to be whatever the execution context eventually becomes |
||
string
|
Performs parameterized substitutions on a string |
|
Set a property from a dot-separated string, such as “A |
Clones objects (including DOM nodes) and all children. Warning: do not clone cyclic structures.
Return: instance
ARGUMENT |
TYPE |
DESCRIPTION |
---|---|---|
|
anything
|
The object to clone |
Returns a new object which “looks” to obj for properties which it does not have a value for. Optionally takes a bag of properties to seed the returned object with initially. This is a small implementation of the Boodman/Crockford delegation pattern in JavaScript. An intermediate object constructor mediates the prototype chain for the returned object, using it to delegate down to obj for property lookup when object-local lookup fails. This can be thought of similarly to ES4’s “wrap”, save that it does not act on types but rather on pure objects.
Return: any
ARGUMENT |
TYPE |
DESCRIPTION |
---|---|---|
|
Object
|
The object to delegate to for properties not found directly on the return object or in props. |
|
Object…
|
an object containing properties to assign to the returned object |
var foo = { bar: "baz" };
var thinger = lang.delegate(foo, { thud: "xyzzy"});
thinger.bar == "baz"; // delegated to foo
foo.thud == undefined; // by definition
thinger.thud == "xyzzy"; // mixed in from props
foo.bar = "thonk";
thinger.bar == "thonk"; // still delegated to foo's bar
determine if an object supports a given method useful for longer api chains where you have to test each object in the chain. Useful for object and method detection.
Return: boolean
ARGUMENT |
TYPE |
DESCRIPTION |
---|---|---|
|
String
|
Path to an object, in the form “A.B.C”. |
|
Object
|
Object to use as root of path. Defaults to ‘dojo.global’. Null may be passed. |
// define an object
var foo = {
bar: { }
};
// search the global scope
lang.exists("foo.bar"); // true
lang.exists("foo.bar.baz"); // false
// search from a particular scope
lang.exists("bar", foo); // true
lang.exists("bar.baz", foo); // false
Adds all properties and methods of props to constructor’s prototype, making them available to all instances created with constructor.
Return: object
ARGUMENT |
TYPE |
DESCRIPTION |
---|---|---|
|
Object
|
Target constructor to extend. |
|
Object
|
One or more objects to mix into ctor.prototype |
Get a property from a dot-separated string, such as “A.B.C” Useful for longer api chains where you have to test each object in the chain, or when you have an object reference in string format.
Return: any
ARGUMENT |
TYPE |
DESCRIPTION |
---|---|---|
|
String
|
Path to an property, in the form “A.B.C”. |
|
Boolean
|
Optional. Defaults to false. If true, Objects will be created at any point along the ‘path’ that is undefined. |
|
Object
|
Optional. Object to use as root of path. Defaults to ‘dojo.global’. Null may be passed. |
Returns a function that will only ever execute in the given scope. This allows for easy use of object member functions in callbacks and other places in which the “this” keyword may otherwise not reference the expected scope. Any number of default positional arguments may be passed as parameters beyond “method”. Each of these values will be used to “placehold” (similar to curry) for the hitched function.
Return: function
Expansion on the default positional arguments passed along from hitch. Passed args are mixed first, additional args after.
var foo = { bar: function(a, b, c){ console.log(a, b, c); } };
var fn = lang.hitch(foo, "bar", 1, 2);
fn(3); // logs "1, 2, 3"
var foo = { bar: 2 };
lang.hitch(foo, function(){ this.bar = 10; })();
execute an anonymous function in scope of foo
Return true if it is an Array.
Return: boolean
ARGUMENT |
TYPE |
DESCRIPTION |
---|---|---|
|
anything
|
Item to test. |
similar to isArray() but more permissive Doesn’t strongly test for “arrayness”. Instead, settles for “isn’t a string or number and has a length property”. Arguments objects and DOM collections will return true when passed to isArrayLike(), but will return false when passed to isArray().
Return: boolean
ARGUMENT |
TYPE |
DESCRIPTION |
---|---|---|
|
anything
|
Item to test. |
Return true if it is a Function
Return: boolean
ARGUMENT |
TYPE |
DESCRIPTION |
---|---|---|
|
anything
|
Item to test. |
Returns true if it is a JavaScript object (or an Array, a Function or null)
Return: boolean
ARGUMENT |
TYPE |
DESCRIPTION |
---|---|---|
|
anything
|
Item to test. |
Return true if it is a String
Return: boolean
ARGUMENT |
TYPE |
DESCRIPTION |
---|---|---|
|
anything
|
Item to test. |
Copies/adds all properties of one or more sources to dest; returns dest. All properties, including functions (sometimes termed “methods”), excluding any non-standard extensions found in Object.prototype, are copied/added from sources to dest. sources are processed left to right. The Javascript assignment operator is used to copy/add each property; therefore, by default, mixin executes a so-called “shallow copy” and aggregate types are copied/added by reference.
Return: object
Many class constructors often take an object which specifies values to be configured on the object. In this case, it is often simplest to call lang.mixin on the this object:
declare("acme.Base", null, {
constructor: function(properties){
// property configuration:
lang.mixin(this, properties);
console.log(this.quip);
// ...
},
quip: "I wasn't born yesterday, you know - I've seen movies.",
// ...
});
// create an instance of the class and configure it
var b = new acme.Base({quip: "That's what it does!" });
Copy properties from multiple objects
var flattened = lang.mixin(
{
name: "Frylock",
braces: true
},
{
name: "Carl Brutanananadilewski"
}
);
// will print "Carl Brutanananadilewski"
console.log(flattened.name);
// will print "true"
console.log(flattened.braces);
Similar to hitch() except that the scope object is left to be whatever the execution context eventually becomes. Calling lang.partial is the functional equivalent of calling:
lang.hitch(null, funcName, ...);
Performs parameterized substitutions on a string. Throws an exception if any parameter is unmatched.
Return: string
ARGUMENT |
TYPE |
DESCRIPTION |
---|---|---|
|
String
|
String to be used as a template. |
|
Object
Function
|
If an object, it is used as a dictionary to look up substitutions. If a function, it is called for every substitution with following parameters: a whole match, a name, an offset, and the whole template string (see https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/String/replace for more details). |
|
RegEx
|
Optional regular expression objects that overrides the default pattern. Must be global and match one item. The default is: /{([^}]+)}/g, which matches patterns like that: “{xxx}”, where “xxx” is any sequence of characters, which doesn’t include “}”. |
// uses a dictionary for substitutions:
lang.replace("Hello, {name.first} {name.last} AKA {nick}!",
{
nick: "Bob",
name: {
first: "Robert",
middle: "X",
last: "Cringely"
}
});
// returns: Hello, Robert Cringely AKA Bob!
// uses an array for substitutions:
lang.replace("Hello, {0} {2}!",
["Robert", "X", "Cringely"]);
// returns: Hello, Robert Cringely!
// uses a function for substitutions:
function sum(a){
var t = 0;
arrayforEach(a, function(x){ t += x; });
return t;
}
lang.replace(
"{count} payments averaging {avg} USD per payment.",
lang.hitch(
{ payments: [11, 16, 12] },
function(_, key){
switch(key){
case "count": return this.payments.length;
case "min": return Math.min.apply(Math, this.payments);
case "max": return Math.max.apply(Math, this.payments);
case "sum": return sum(this.payments);
case "avg": return sum(this.payments) / this.payments.length;
}
}
)
);
// prints: 3 payments averaging 13 USD per payment.
// uses an alternative PHP-like pattern for substitutions:
lang.replace("Hello, ${0} ${2}!",
["Robert", "X", "Cringely"], /\$\{([^\}]+)\}/g);
// returns: Hello, Robert Cringely!
Set a property from a dot-separated string, such as “A.B.C” Useful for longer api chains where you have to test each object in the chain, or when you have an object reference in string format. Objects are created as needed along path. Returns the passed value if setting is successful or undefined if not.
ARGUMENT |
TYPE |
DESCRIPTION |
---|---|---|
|
String
|
Path to a property, in the form “A.B.C”. |
|
anything
|
value or object to place at location given by name |
|
Object
|
Optional. Object to use as root of path. Defaults to dojo.global. |
Set the value of foo.bar.baz, regardless of whether intermediate objects already exist:
lang.setObject("foo.bar.baz", value);
Without lang.setObject, we often see code like this:
// ensure that intermediate objects are available
if(!obj["parent"]){ obj.parent = {}; }
if(!obj.parent["child"]){ obj.parent.child = {}; }
// now we can safely set the property
obj.parent.child.prop = "some value";
Whereas with lang.setObject, we can shorten that to:
lang.setObject("parent.child.prop", "some value", obj);