#

API Docs for: 3.10.3
Show: Inherited Protected Private Deprecated

# HistoryBase Class

Defined in: `history/js/history-base.js:13`
Module: history-base
Parent Module: history

Provides global state management backed by an object, but with no browser history integration. For actual browser history integration and back/forward support, use the history-html5 or history-hash modules.

- Index
- Methods
- Properties
- Events

## Item Index

### Methods

- _change
- _defChangeFn
- _fireChangeEvent
- _fireEvents
- _fireRemoveEvent
- _init
- _isSimpleObject
- _resolveChanges
- _storeState
- add
- addValue
- get
- replace
- replaceValue

### Properties

- _config
- _initialState
- force
- html5 static
- NAME static
- nativeHashChange static
- SRC_ADD static
- SRC_REPLACE static

### Events

- [key]Change
- [key]Remove
- history:change

## Methods

### `_change`

(

- `src`
- `state`
- `options`

)
protected chainable

Defined in `history/js/history-base.js:377`

Changes the state. This method provides a common implementation shared by the public methods for changing state.

#### Parameters:

- `src` String

  Source of the change, for inclusion in event facades to facilitate filtering.

- `state` Object

  Object hash of key/value pairs.

- `options` Object

  (optional) Zero or more options. See `add()` for a list of supported options.

### `_defChangeFn`

(

- `e`

)
protected

Defined in `history/js/history-base.js:623`

Default `history:change` event handler.

#### Parameters:

- `e` EventFacade

  state change event facade

### `_fireChangeEvent`

(

- `src`
- `key`
- `value`

)
protected

Defined in `history/js/history-base.js:435`

Fires a dynamic "[key]Change" event.

#### Parameters:

- `src` String

  source of the change, for inclusion in event facades to facilitate filtering

- `key` String

  key of the item that was changed

- `value` Object

  object hash containing newVal and prevVal properties for the changed item

### `_fireEvents`

(

- `src`
- `changes`
- `options`

)
protected

Defined in `history/js/history-base.js:402`

Called by _resolveChanges() when the state has changed. This method takes care of actually firing the necessary events.

#### Parameters:

- `src` String

  Source of the changes, for inclusion in event facades to facilitate filtering.

- `changes` Object

  Resolved changes.

- `options` Object

  Zero or more options. See `add()` for a list of supported options.

### `_fireRemoveEvent`

(

- `src`
- `key`
- `value`

)
protected

Defined in `history/js/history-base.js:494`

Fires a dynamic "[key]Remove" event.

#### Parameters:

- `src` String

  source of the change, for inclusion in event facades to facilitate filtering

- `key` String

  key of the item that was removed

- `value` Mixed

  value of the item prior to its removal

### `_init`

(

- `config`

)
protected

Defined in `history/js/history-base.js:158`

Initializes this HistoryBase instance. This method is called by the constructor.

#### Parameters:

- `config` Object

  configuration object

### `_isSimpleObject`

(

- `value`

)
Boolean private

Defined in `history/js/history-base.js:72`

Returns `true` if value is a simple object and not a function or an array.

#### Parameters:

- `value` Mixed

#### Returns:

Boolean:

### `_resolveChanges`

(

- `src`
- `newState`
- `options`

)
protected

Defined in `history/js/history-base.js:544`

Resolves the changes (if any) between newState and the current state and fires appropriate events if things have changed.

#### Parameters:

- `src` String

  source of the changes, for inclusion in event facades to facilitate filtering

- `newState` Object

  object hash of key/value pairs representing the new state

- `options` Object

  Zero or more options. See `add()` for a list of supported options.

### `_storeState`

(

- `src`
- `newState`
- `options`

)
protected

Defined in `history/js/history-base.js:603`

Stores the specified state. Don't call this method directly; go through _resolveChanges() to ensure that changes are resolved and all events are fired properly.

#### Parameters:

- `src` String

  source of the changes

- `newState` Object

  new state to store

- `options` Object

  Zero or more options. See `add()` for a list of supported options.

### `add`

(

- `state`
- `options`

)
chainable

Defined in `history/js/history-base.js:265`

Adds a state entry with new values for the specified keys. By default, the new state will be merged into the existing state, and new values will override existing values. Specifying a `null` or `undefined` value will cause that key to be removed from the new state entry.

#### Parameters:

- `state` Object

  Object hash of key/value pairs.

- `options` Object

  (optional) Zero or more of the following options:

  merge (Boolean)

    If `true` (the default), the new state will be merged into the existing state. New values will override existing values, and `null` or `undefined` values will be removed from the state.

          <p>
          If <code>false</code>, the existing state will be discarded as a
          whole and the new state will take its place.
          </p>
        </dd>

### `addValue`

(

- `key`
- `value`
- `options`

)
chainable

Defined in `history/js/history-base.js:299`

Adds a state entry with a new value for a single key. By default, the new value will be merged into the existing state values, and will override an existing value with the same key if there is one. Specifying a `null` or `undefined` value will cause the key to be removed from the new state entry.

#### Parameters:

- `key` String

  State parameter key.

- `value` String

  New value.

- `options` Object

  (optional) Zero or more options. See `add()` for a list of supported options.

### `get`

(

- `key`

)
Object | String

Defined in `history/js/history-base.js:319`

Returns the current value of the state parameter specified by key, or an object hash of key/value pairs for all current state parameters if no key is specified.

#### Parameters:

- `key` String

  (optional) State parameter key.

#### Returns:

Object | String: Value of the specified state parameter, or an object hash of key/value pairs for all current state parameters.

### `replace`

(

- `state`
- `options`

)
chainable

Defined in `history/js/history-base.js:340`

Same as `add()` except that a new browser history entry will not be created. Instead, the current history entry will be replaced with the new state.

#### Parameters:

- `state` Object

  Object hash of key/value pairs.

- `options` Object

  (optional) Zero or more options. See `add()` for a list of supported options.

### `replaceValue`

(

- `key`
- `value`
- `options`

)
chainable

Defined in `history/js/history-base.js:357`

Same as `addValue()` except that a new browser history entry will not be created. Instead, the current history entry will be replaced with the new state.

#### Parameters:

- `key` String

  State parameter key.

- `value` String

  New value.

- `options` Object

  (optional) Zero or more options. See `add()` for a list of supported options.

## Properties

### `_config`

Object protected

Defined in `history/js/history-base.js:169`

Configuration object provided by the user on instantiation, or an empty object if one wasn't provided.

Default: {}

### `_initialState`

Object | Null protected

Defined in `history/js/history-base.js:190`

Resolved initial state: a merge of the user-supplied initial state (if any) and any initial state provided by a subclass. This may differ from `_config.initialState`. If neither the config nor a subclass supplies an initial state, this property will be `null`.

Default: {}

### `force`

Boolean

Defined in `history/js/history-base.js:180`

If `true`, a `history:change` event will be fired whenever the URL changes, even if there is no associated state change.

Default: false

### `html5`

Boolean static

Defined in `history/js/history-base.js:118`

Whether or not this browser supports the HTML5 History API.

### `NAME`

String static

Defined in `history/js/history-base.js:87`

Name of this component.

### `nativeHashChange`

Boolean static

Defined in `history/js/history-base.js:133`

Whether or not this browser supports the `window.onhashchange` event natively. Note that even if this is `true`, you may still want to use HistoryHash's synthetic `hashchange` event since it normalizes implementation differences and fixes spec violations across various browsers.

### `SRC_ADD`

String final static

Defined in `history/js/history-base.js:96`

Constant used to identify state changes originating from the `add()` method.

### `SRC_REPLACE`

String final static

Defined in `history/js/history-base.js:107`

Constant used to identify state changes originating from the `replace()` method.

## Events

### `[key]Change`

Defined in `history/js/history-base.js:447`

Dynamic event fired when an individual history item is added or changed. The name of this event depends on the name of the key that changed. To listen to change events for a key named "foo", subscribe to the `fooChange` event; for a key named "bar", subscribe to `barChange`, etc.

Key-specific events are only fired for instance-level changes; that is, changes that were made via the same History instance on which the event is subscribed. To be notified of changes made by other History instances, subscribe to the global `history:change` event.

#### Event Payload:

- `e` EventFacade

  Event facade with the following additional properties:

  newVal (mixed)
    The new value of the item after the change.
  prevVal (mixed)
    The previous value of the item before the change, or `undefined` if the item was just added and has no previous value.
  src (String)
    The source of the event. This can be used to selectively ignore events generated by certain sources.

### `[key]Remove`

Defined in `history/js/history-base.js:505`

Dynamic event fired when an individual history item is removed. The name of this event depends on the name of the key that was removed. To listen to remove events for a key named "foo", subscribe to the `fooRemove` event; for a key named "bar", subscribe to `barRemove`, etc.

Key-specific events are only fired for instance-level changes; that is, changes that were made via the same History instance on which the event is subscribed. To be notified of changes made by other History instances, subscribe to the global `history:change` event.

#### Event Payload:

- `e` EventFacade

  Event facade with the following additional properties:

  prevVal (mixed)
    The value of the item before it was removed.
  src (String)
    The source of the event. This can be used to selectively ignore events generated by certain sources.

### `history:change`

Defined in `history/js/history-base.js:205`

Fired when the state changes. To be notified of all state changes regardless of the History or YUI instance that generated them, subscribe to this event on `Y.Global`. If you would rather be notified only about changes generated by this specific History instance, subscribe to this event on the instance.

#### Event Payload:

- `e` EventFacade

  Event facade with the following additional properties:

  changed (Object)
    Object hash of state items that have been added or changed. The key is the item key, and the value is an object containing `newVal` and `prevVal` properties representing the values of the item both before and after the change. If the item was newly added, `prevVal` will be `undefined`.
  newVal (Object)
    Object hash of key/value pairs of all state items after the change.
  prevVal (Object)
    Object hash of key/value pairs of all state items before the change.
  removed (Object)
    Object hash of key/value pairs of state items that have been removed. Values are the old values prior to removal.
  src (String)
    The source of the event. This can be used to selectively ignore events generated by certain sources.