# Interface: HistoryManagerInterface (/jsdoc/pixi-vn/index/interfaces/HistoryManagerInterface) Defined in: [src/history/interfaces/HistoryManagerInterface.ts:12](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L12) Properties [#properties] back [#back] \> **back**: (`props`, `options?`) => `Promise`\<[`StepLabelResultType`](/jsdoc/pixi-vn/index/type-aliases/StepLabelResultType)> Defined in: [src/history/interfaces/HistoryManagerInterface.ts:46](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L46) Go back to the last step and add it to the history. Parameters [#parameters] props [#props] `StepLabelProps` The step label properties. options? [#options] The navigation options. steps? [#steps] `number` The number of steps to go back. Must be greater than 0. **Default** ```ts 1 ``` Returns [#returns] `Promise`\<[`StepLabelResultType`](/jsdoc/pixi-vn/index/type-aliases/StepLabelResultType)> *** canGoBack [#cangoback] \> `readonly` **canGoBack**: `boolean` Defined in: [src/history/interfaces/HistoryManagerInterface.ts:62](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L62) Return true if it is possible to go back. *** currentLabelHistory [#currentlabelhistory] \> `readonly` **currentLabelHistory**: [`NarrationHistory`](/jsdoc/pixi-vn/index/interfaces/NarrationHistory)\[] Defined in: [src/history/interfaces/HistoryManagerInterface.ts:23](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L23) Get the history of the latest steps belonging to the current label and its child labels. Returns [#returns-1] the history of the dialogues, choices and steps *** diffMap [#diffmap] \> `readonly` **diffMap**: [`CachedMap`](/jsdoc/pixi-vn/index/classes/CachedMap)\<`number`, `Difference`\[]> Defined in: [src/history/interfaces/HistoryManagerInterface.ts:122](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L122) Map that contains all the differences between the steps in the history. The differences will be used to restore a step. **Don't edit unless you're sure what you're doing.** *** lastKey [#lastkey] \> `readonly` **lastKey**: `number` | `null` Defined in: [src/history/interfaces/HistoryManagerInterface.ts:91](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L91) Get the last key (id) of the history. *** narrationMap [#narrationmap] \> `readonly` **narrationMap**: [`CachedMap`](/jsdoc/pixi-vn/index/classes/CachedMap)\<`number`, [`NarrationHistory`](/jsdoc/pixi-vn/index/interfaces/NarrationHistory)> Defined in: [src/history/interfaces/HistoryManagerInterface.ts:128](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L128) Map that contains all the narration history. **Don't edit unless you're sure what you're doing.** *** narrativeHistory [#narrativehistory] \> `readonly` **narrativeHistory**: [`NarrationHistory`](/jsdoc/pixi-vn/index/interfaces/NarrationHistory)\[] Defined in: [src/history/interfaces/HistoryManagerInterface.ts:17](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L17) Get the narrative history. Returns [#returns-2] the history of the dialogues, choices and steps *** size [#size] \> `readonly` **size**: `number` Defined in: [src/history/interfaces/HistoryManagerInterface.ts:87](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L87) Number of items in the history. *** stepLimitSaved [#steplimitsaved] \> **stepLimitSaved**: `number` Defined in: [src/history/interfaces/HistoryManagerInterface.ts:34](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L34) The number of steps to keep in the history into the save file. The other older steps will be compressed will be used in [HistoryManagerInterface.narrativeHistory](#narrativehistory) to show the older dialogues. In the compressed steps, the canvas and storage information will be removed. This also means that a player, after saving and loading a save, will only be able to go back to NarrationManagerInterface.stepLimitSaved steps. If you want to keep all steps in the history, you can set this value to Infinity. *** stepsInfoMap [#stepsinfomap] \> `readonly` **stepsInfoMap**: [`CachedMap`](/jsdoc/pixi-vn/index/classes/CachedMap)\<`number`, `Omit`\<[`HistoryStep`](/jsdoc/pixi-vn/index/interfaces/HistoryStep), `"diff"`>> Defined in: [src/history/interfaces/HistoryManagerInterface.ts:115](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L115) Map that contains all information about the steps in the history. **Don't edit unless you're sure what you're doing.** Methods [#methods] add() [#add] \> **add**(`historyInfo?`, `opstions?`): `void` Defined in: [src/history/interfaces/HistoryManagerInterface.ts:71](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L71) Add a step to the history. Parameters [#parameters-1] historyInfo? [#historyinfo] `HistoryInfo` Info about the step to add. opstions? [#opstions] Options to add the step. ignoreSameStep? [#ignoresamestep] `boolean` If true, the step will not be added to the history if the current step is the same as the last step. Returns [#returns-3] `void` *** blockGoBack() [#blockgoback] \> **blockGoBack**(): `void` Defined in: [src/history/interfaces/HistoryManagerInterface.ts:58](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L58) Block the go back function. Returns [#returns-4] `void` *** clear() [#clear] \> **clear**(): `void` Defined in: [src/history/interfaces/HistoryManagerInterface.ts:83](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L83) Clear the history. Returns [#returns-5] `void` *** delete() [#delete] \> **delete**(`stepIndex`): `void` Defined in: [src/history/interfaces/HistoryManagerInterface.ts:109](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L109) Remove a step from the history. Parameters [#parameters-2] stepIndex [#stepindex] `number` The key (id) of the step to remove. Returns [#returns-6] `void` True if the step was removed, false if it was not found. *** export() [#export] \> **export**(): [`HistoryGameState`](/jsdoc/pixi-vn/index/interfaces/HistoryGameState) Defined in: [src/history/interfaces/HistoryManagerInterface.ts:136](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L136) Export the history to an object. Returns [#returns-7] [`HistoryGameState`](/jsdoc/pixi-vn/index/interfaces/HistoryGameState) The history in an object. *** get() [#get] \> **get**(`stepIndex`): [`NarrationHistory`](/jsdoc/pixi-vn/index/interfaces/NarrationHistory) | `undefined` Defined in: [src/history/interfaces/HistoryManagerInterface.ts:103](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L103) Get a step from the history. **Note:** If the step not contains any information, this method will return undefined. Parameters [#parameters-3] stepIndex [#stepindex-1] `number` The key (id) of the step to get. Returns [#returns-8] [`NarrationHistory`](/jsdoc/pixi-vn/index/interfaces/NarrationHistory) | `undefined` The step. *** keys() [#keys] \> **keys**(): `MapIterator`\<`number`> Defined in: [src/history/interfaces/HistoryManagerInterface.ts:95](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L95) Get all the keys (id) of the history. Returns [#returns-9] `MapIterator`\<`number`> *** removeNarrativeHistory() [#removenarrativehistory] \> **removeNarrativeHistory**(`itemsNumber?`): `void` Defined in: [src/history/interfaces/HistoryManagerInterface.ts:39](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L39) Delete the narrative history. Parameters [#parameters-4] itemsNumber? [#itemsnumber] `number` The number of items to delete. If undefined, all items will be deleted. Returns [#returns-10] `void` *** restore() [#restore] \> **restore**(`data`): `Promise`\<`void`> Defined in: [src/history/interfaces/HistoryManagerInterface.ts:141](https://github.com/DRincs-Productions/pixi-vn/blob/998c1a75c5978f24c0dc137af5f42b90b2803967/src/history/interfaces/HistoryManagerInterface.ts#L141) Restore the history from an object. Parameters [#parameters-5] data [#data] `object` The history in an object. Returns [#returns-11] `Promise`\<`void`>