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# `ng`

# ng (core module)

The ng module is loaded by default when an AngularJS application is started. The module itself contains the essential components for an AngularJS application to function. The table below lists a high level breakdown of each of the services/factories, filters, directives and testing components available within this core module.

## Module Components

### Function

Name | Description
--- | ---
angular.lowercase | Converts the specified string to lowercase.
angular.uppercase | Converts the specified string to uppercase.
angular.forEach | Invokes the `iterator` function once for each item in `obj` collection, which can be either an object or an array. The `iterator` function is invoked with `iterator(value, key)`, where `value` is the value of an object property or an array element and `key` is the object property key or array element index. Specifying a `context` for the function is optional.
angular.extend | Extends the destination object `dst` by copying all of the properties from the `src` object(s) to `dst`. You can specify multiple `src` objects.
angular.noop | A function that performs no operations. This function can be useful when writing code in the functional style.
         function foo(callback) {
           var result = calculateResult();
           (callback || angular.noop)(result);
         }
angular.identity | A function that returns its first argument. This function is useful when writing code in the functional style.
angular.isUndefined | Determines if a reference is undefined.
angular.isDefined | Determines if a reference is defined.
angular.isObject | Determines if a reference is an `Object`. Unlike `typeof` in JavaScript, `null`s are not considered to be objects. Note that JavaScript arrays are objects.
angular.isString | Determines if a reference is a `String`.
angular.isNumber | Determines if a reference is a `Number`.
angular.isDate | Determines if a value is a date.
angular.isArray | Determines if a reference is an `Array`.
angular.isFunction | Determines if a reference is a `Function`.
angular.isElement | Determines if a reference is a DOM element (or wrapped jQuery element).
angular.copy | Creates a deep copy of `source`, which should be an object or an array.
angular.equals | Determines if two objects or two values are equivalent. Supports value types, regular expressions, arrays and objects.
angular.bind | Returns a function which calls function `fn` bound to `self` (`self` becomes the `this` for `fn`). You can supply optional `args` that are prebound to the function. This feature is also known as partial application, as distinguished from function currying.
angular.toJson | Serializes input into a JSON-formatted string. Properties with leading $ characters will be stripped since angular uses this notation internally.
angular.fromJson | Deserializes a JSON string.
angular.bootstrap | Use this function to manually start up angular application.
angular.injector | Creates an injector function that can be used for retrieving services as well as for dependency injection (see dependency injection).
angular.element | Wraps a raw DOM element or HTML string as a jQuery element.
angular.module | The `angular.module` is a global place for creating, registering and retrieving Angular modules. All modules (angular core or 3rd party) that should be available to an application must be registered using this mechanism.

### Directive

Name | Description
--- | ---
ngApp | Use this directive to auto-bootstrap an AngularJS application. The `ngApp` directive designates the root element of the application and is typically placed near the root element of the page - e.g. on the `<body>` or `<html>` tags.
a | Modifies the default behavior of the html A tag so that the default action is prevented when the href attribute is empty.
ngHref | Using Angular markup like `{{hash}}` in an href attribute will make the link go to the wrong URL if the user clicks it before Angular has a chance to replace the `{{hash}}` markup with its value. Until Angular replaces the markup the link will be broken and will most likely return a 404 error.
ngSrc | Using Angular markup like `{{hash}}` in a `src` attribute doesn't work right: The browser will fetch from the URL with the literal text `{{hash}}` until Angular replaces the expression inside `{{hash}}`. The `ngSrc` directive solves this problem.
ngSrcset | Using Angular markup like `{{hash}}` in a `srcset` attribute doesn't work right: The browser will fetch from the URL with the literal text `{{hash}}` until Angular replaces the expression inside `{{hash}}`. The `ngSrcset` directive solves this problem.
ngDisabled | We shouldn't do this, because it will make the button enabled on Chrome/Firefox but not on IE8 and older IEs:
    <div ng-init="scope = { isDisabled: false }">
     <button disabled="{{scope.isDisabled}}">Disabled</button>
    </div>
ngChecked | The HTML specification does not require browsers to preserve the values of boolean attributes such as checked. (Their presence means true and their absence means false.) If we put an Angular interpolation expression into such an attribute then the binding information would be lost when the browser removes the attribute. The `ngChecked` directive solves this problem for the `checked` attribute. This complementary directive is not removed by the browser and so provides a permanent reliable place to store the binding information.
ngReadonly | The HTML specification does not require browsers to preserve the values of boolean attributes such as readonly. (Their presence means true and their absence means false.) If we put an Angular interpolation expression into such an attribute then the binding information would be lost when the browser removes the attribute. The `ngReadonly` directive solves this problem for the `readonly` attribute. This complementary directive is not removed by the browser and so provides a permanent reliable place to store the binding information.
ngSelected | The HTML specification does not require browsers to preserve the values of boolean attributes such as selected. (Their presence means true and their absence means false.) If we put an Angular interpolation expression into such an attribute then the binding information would be lost when the browser removes the attribute. The `ngSelected` directive solves this problem for the `selected` attribute. This complementary directive is not removed by the browser and so provides a permanent reliable place to store the binding information.
ngOpen | The HTML specification does not require browsers to preserve the values of boolean attributes such as open. (Their presence means true and their absence means false.) If we put an Angular interpolation expression into such an attribute then the binding information would be lost when the browser removes the attribute. The `ngOpen` directive solves this problem for the `open` attribute. This complementary directive is not removed by the browser and so provides a permanent reliable place to store the binding information.
ngForm | Nestable alias of `form` directive. HTML does not allow nesting of form elements. It is useful to nest forms, for example if the validity of a sub-group of controls needs to be determined.
form | Directive that instantiates FormController.
textarea | HTML textarea element control with angular data-binding. The data-binding and validation properties of this element are exactly the same as those of the input element.
input | HTML input element control with angular data-binding. Input control follows HTML5 input types and polyfills the HTML5 validation behavior for older browsers.
ngModel | The `ngModel` directive binds an `input`,`select`, `textarea` (or custom form control) to a property on the scope using NgModelController, which is created and exposed by this directive.
ngChange | Evaluate the given expression when the user changes the input. The expression is evaluated immediately, unlike the JavaScript onchange event which only triggers at the end of a change (usually, when the user leaves the form element or presses the return key). The expression is not evaluated when the value change is coming from the model.
ngList | Text input that converts between a delimited string and an array of strings. The delimiter can be a fixed string (by default a comma) or a regular expression.
ngValue | Binds the given expression to the value of `input[select]` or `input[radio]`, so that when the element is selected, the `ngModel` of that element is set to the bound value.
ngBind | The `ngBind` attribute tells Angular to replace the text content of the specified HTML element with the value of a given expression, and to update the text content when the value of that expression changes.
ngBindTemplate | The `ngBindTemplate` directive specifies that the element text content should be replaced with the interpolation of the template in the `ngBindTemplate` attribute. Unlike `ngBind`, the `ngBindTemplate` can contain multiple `{{` `}}` expressions. This directive is needed since some HTML elements (such as TITLE and OPTION) cannot contain SPAN elements.
ngBindHtml | Creates a binding that will innerHTML the result of evaluating the `expression` into the current element in a secure way. By default, the innerHTML-ed content will be sanitized using the $sanitize service. To utilize this functionality, ensure that `$sanitize` is available, for example, by including `ngSanitize` in your module's dependencies (not in core Angular.) You may also bypass sanitization for values you know are safe. To do so, bind to an explicitly trusted value via $sce.trustAsHtml. See the example under Strict Contextual Escaping (SCE).
ngClass | The `ngClass` directive allows you to dynamically set CSS classes on an HTML element by databinding an expression that represents all classes to be added.
ngClassOdd | The `ngClassOdd` and `ngClassEven` directives work exactly as ngClass, except they work in conjunction with `ngRepeat` and take effect only on odd (even) rows.
ngClassEven | The `ngClassOdd` and `ngClassEven` directives work exactly as ngClass, except they work in conjunction with `ngRepeat` and take effect only on odd (even) rows.
ngCloak | The `ngCloak` directive is used to prevent the Angular html template from being briefly displayed by the browser in its raw (uncompiled) form while your application is loading. Use this directive to avoid the undesirable flicker effect caused by the html template display.
ngController | The `ngController` directive attaches a controller class to the view. This is a key aspect of how angular supports the principles behind the Model-View-Controller design pattern.
ngCsp | Enables CSP (Content Security Policy) support.
ngClick | The ngClick directive allows you to specify custom behavior when an element is clicked.
ngDblclick | The `ngDblclick` directive allows you to specify custom behavior on a dblclick event.
ngMousedown | The ngMousedown directive allows you to specify custom behavior on mousedown event.
ngMouseup | Specify custom behavior on mouseup event.
ngMouseover | Specify custom behavior on mouseover event.
ngMouseenter | Specify custom behavior on mouseenter event.
ngMouseleave | Specify custom behavior on mouseleave event.
ngMousemove | Specify custom behavior on mousemove event.
ngKeydown | Specify custom behavior on keydown event.
ngKeyup | Specify custom behavior on keyup event.
ngKeypress | Specify custom behavior on keypress event.
ngSubmit | Enables binding angular expressions to onsubmit events.
ngFocus | Specify custom behavior on focus event.
ngBlur | Specify custom behavior on blur event.
ngCopy | Specify custom behavior on copy event.
ngCut | Specify custom behavior on cut event.
ngPaste | Specify custom behavior on paste event.
ngIf | The `ngIf` directive removes or recreates a portion of the DOM tree based on an {expression}. If the expression assigned to `ngIf` evaluates to a false value then the element is removed from the DOM, otherwise a clone of the element is reinserted into the DOM.
ngInclude | Fetches, compiles and includes an external HTML fragment.
ngInit | The `ngInit` directive allows you to evaluate an expression in the current scope.
ngNonBindable | The `ngNonBindable` directive tells Angular not to compile or bind the contents of the current DOM element. This is useful if the element contains what appears to be Angular directives and bindings but which should be ignored by Angular. This could be the case if you have a site that displays snippets of code, for instance.
ngPluralize | `ngPluralize` is a directive that displays messages according to en-US localization rules. These rules are bundled with angular.js, but can be overridden (see Angular i18n dev guide). You configure ngPluralize directive by specifying the mappings between plural categories and the strings to be displayed.
ngRepeat | The `ngRepeat` directive instantiates a template once per item from a collection. Each template instance gets its own scope, where the given loop variable is set to the current collection item, and `$index` is set to the item index or key.
ngShow | The `ngShow` directive shows or hides the given HTML element based on the expression provided to the ngShow attribute. The element is shown or hidden by removing or adding the `ng-hide` CSS class onto the element. The `.ng-hide` CSS class is predefined in AngularJS and sets the display style to none (using an !important flag). For CSP mode please add `angular-csp.css` to your html file (see ngCsp).
ngHide | The `ngHide` directive shows or hides the given HTML element based on the expression provided to the ngHide attribute. The element is shown or hidden by removing or adding the `ng-hide` CSS class onto the element. The `.ng-hide` CSS class is predefined in AngularJS and sets the display style to none (using an !important flag). For CSP mode please add `angular-csp.css` to your html file (see ngCsp).
ngStyle | The `ngStyle` directive allows you to set CSS style on an HTML element conditionally.
ngSwitch | The `ngSwitch` directive is used to conditionally swap DOM structure on your template based on a scope expression. Elements within `ngSwitch` but without `ngSwitchWhen` or `ngSwitchDefault` directives will be preserved at the location as specified in the template.
ngTransclude | Directive that marks the insertion point for the transcluded DOM of the nearest parent directive that uses transclusion.
script | Load the content of a `<script>` element into `$templateCache`, so that the template can be used by `ngInclude`, `ngView`, or directives. The type of the `<script>` element must be specified as `text/ng-template`, and a cache name for the template must be assigned through the element's `id`, which can then be used as a directive's `templateUrl`.
select | HTML `SELECT` element with angular data-binding.

### Object

Name | Description
--- | ---
angular.version | An object that contains information about the current AngularJS version. This object has the following properties:

### Type

Name | Description
--- | ---
angular.Module | Interface for configuring angular modules.
$cacheFactory.Cache | A cache object used to store and retrieve data, primarily used by $http and the script directive to cache templates and other data.
$compile.directive.Attributes | A shared object between directive compile / linking functions which contains normalized DOM element attributes. The values reflect current binding state `{{ }}`. The normalization is needed since all of these are treated as equivalent in Angular:
form.FormController | `FormController` keeps track of all its controls and nested forms as well as the state of them, such as being valid/invalid or dirty/pristine.
ngModel.NgModelController | `NgModelController` provides API for the `ng-model` directive. The controller contains services for data-binding, validation, CSS updates, and value formatting and parsing. It purposefully does not contain any logic which deals with DOM rendering or listening to DOM events. Such DOM related logic should be provided by other directives which make use of `NgModelController` for data-binding.
$rootScope.Scope | A root scope can be retrieved using the $rootScope key from the $injector. Child scopes are created using the $new() method. (Most scopes are created automatically when compiled HTML template is executed.)

### Service

Name | Description
--- | ---
$anchorScroll | When called, it checks current value of `$location.hash()` and scrolls to the related element, according to rules specified in Html5 spec.
$animate | The $animate service provides rudimentary DOM manipulation functions to insert, remove and move elements within the DOM, as well as adding and removing classes. This service is the core service used by the ngAnimate $animator service which provides high-level animation hooks for CSS and JavaScript.
$cacheFactory | Factory that constructs Cache objects and gives access to them.
$templateCache | The first time a template is used, it is loaded in the template cache for quick retrieval. You can load templates directly into the cache in a `script` tag, or by consuming the `$templateCache` service directly.
$compile | Compiles an HTML string or DOM into a template and produces a template function, which can then be used to link `scope` and the template together.
$controller | `$controller` service is responsible for instantiating controllers.
$document | A jQuery or jqLite wrapper for the browser's `window.document` object.
$exceptionHandler | Any uncaught exception in angular expressions is delegated to this service. The default implementation simply delegates to `$log.error` which logs it into the browser console.
$filter | Filters are used for formatting data displayed to the user.
$http | The `$http` service is a core Angular service that facilitates communication with the remote HTTP servers via the browser's XMLHttpRequest object or via JSONP.
$httpBackend | HTTP backend used by the service that delegates to XMLHttpRequest object or JSONP and deals with browser incompatibilities.
$interpolate | Compiles a string with markup into an interpolation function. This service is used by the HTML $compile service for data binding. See $interpolateProvider for configuring the interpolation markup.
$interval | Angular's wrapper for `window.setInterval`. The `fn` function is executed every `delay` milliseconds.
$locale | $locale service provides localization rules for various Angular components. As of right now the only public api is:
$location | The $location service parses the URL in the browser address bar (based on the window.location) and makes the URL available to your application. Changes to the URL in the address bar are reflected into $location service and changes to $location are reflected into the browser address bar.
$log | Simple service for logging. Default implementation safely writes the message into the browser's console (if present).
$parse | Converts Angular expression into a function.
$q | A promise/deferred implementation inspired by Kris Kowal's Q.
$rootElement | The root element of Angular application. This is either the element where ngApp was declared or the element passed into `angular.bootstrap`. The element represent the root element of application. It is also the location where the applications $injector service gets published, it can be retrieved using `$rootElement.injector()`.
$rootScope | Every application has a single root scope. All other scopes are descendant scopes of the root scope. Scopes provide separation between the model and the view, via a mechanism for watching the model for changes. They also provide an event emission/broadcast and subscription facility. See the developer guide on scopes.
$sceDelegate | `$sceDelegate` is a service that is used by the `$sce` service to provide Strict Contextual Escaping (SCE) services to AngularJS.
$sce | `$sce` is a service that provides Strict Contextual Escaping services to AngularJS.
$timeout | Angular's wrapper for `window.setTimeout`. The `fn` function is wrapped into a try/catch block and delegates any exceptions to $exceptionHandler service.
$window | A reference to the browser's `window` object. While `window` is globally available in JavaScript, it causes testability problems, because it is a global variable. In angular we always refer to it through the `$window` service, so it may be overridden, removed or mocked for testing.

### Provider

Name | Description
--- | ---
$animateProvider | Default implementation of $animate that doesn't perform any animations, instead just synchronously performs DOM updates and calls done() callbacks.
$compileProvider |
$controllerProvider | The $controller service is used by Angular to create new controllers.
$filterProvider | Filters are just functions which transform input to an output. However filters need to be Dependency Injected. To achieve this a filter definition consists of a factory function which is annotated with dependencies and is responsible for creating a filter function.
$httpProvider | Use `$httpProvider` to change the default behavior of the $http service.
$interpolateProvider | Used for configuring the interpolation markup. Defaults to `{{` and `}}`.
$locationProvider | Use the `$locationProvider` to configure how the application deep linking paths are stored.
$logProvider | Use the `$logProvider` to configure how the application logs messages
$parseProvider | `$parseProvider` can be used for configuring the default behavior of the $parse service.
$rootScopeProvider | Provider for the $rootScope service.
$sceDelegateProvider | The `$sceDelegateProvider` provider allows developers to configure the $sceDelegate service. This allows one to get/set the whitelists and blacklists used to ensure that the URLs used for sourcing Angular templates are safe. Refer $sceDelegateProvider.resourceUrlWhitelist and $sceDelegateProvider.resourceUrlBlacklist
$sceProvider | The $sceProvider provider allows developers to configure the $sce service. enable/disable Strict Contextual Escaping (SCE) in a module override the default implementation with a custom delegate

### Input

Name | Description
--- | ---
input[text] | Standard HTML text input with angular data binding, inherited by most of the `input` elements.
input[number] | Text input with number validation and transformation. Sets the `number` validation error if not a valid number.
input[url] | Text input with URL validation. Sets the `url` validation error key if the content is not a valid URL.
input[email] | Text input with email validation. Sets the `email` validation error key if not a valid email address.
input[radio] | HTML radio button.
input[checkbox] | HTML checkbox.

### Filter

Name | Description
--- | ---
filter | Selects a subset of items from `array` and returns it as a new array.
currency | Formats a number as a currency (ie $1,234.56). When no currency symbol is provided, default symbol for current locale is used.
number | Formats a number as text.
date | Formats `date` to a string based on the requested `format`.
json | Allows you to convert a JavaScript object into JSON string.
lowercase | Converts string to lowercase.
uppercase | Converts string to uppercase.
limitTo | Creates a new array or string containing only a specified number of elements. The elements are taken from either the beginning or the end of the source array or string, as specified by the value and sign (positive or negative) of `limit`.
orderBy | Orders a specified `array` by the `expression` predicate. It is ordered alphabetically for strings and numerically for numbers. Note: if you notice numbers are not being sorted correctly, make sure they are actually being saved as numbers and not strings.