ViewTreeWalker

Iterator boundaries.

When the iterator is walking 'forward' on the end of boundary or is walking 'backward' on the start of boundary, then { done: true } is returned.

If boundaries are not defined they are set before first and after last child of the root node.

Walking direction. Defaults 'forward'.

Flag indicating whether iterator should ignore elementEnd tags. If set to true, walker will not return a parent node of the start position. Each ViewElement will be returned once. When set to false each element might be returned twice: for 'elementStart' and 'elementEnd'.

Iterator position. If start position is not defined then position depends on direction. If direction is 'forward' position starts form the beginning, when direction is 'backward' position starts from the end.

Flag indicating whether iterator should enter elements or not. If the iterator is shallow child nodes of any iterated node will not be returned along with elementEnd tag.

Flag indicating whether all characters from ViewText should be returned as one ViewText or one by one as ViewTextProxy.

End boundary parent.

Start boundary parent.

Iterator position. If start position is not defined then position depends on direction. If direction is 'forward' position starts form the beginning, when direction is 'backward' position starts from the end.

Creates a range iterator. All parameters are optional, but you have to specify either boundaries or startPosition.

Parameters

options : ViewTreeWalkerOptions

Object with configuration.

Defaults to {}

Iterable interface.

Returns

IterableIterator<ViewTreeWalkerValue>

Moves tree walker position to provided position. Tree walker will continue traversing from that position.

Note: in contrary to skip, this method does not iterate over the nodes along the way. It simply sets the current tree walker position to a new one. From the performance standpoint, it is better to use jumpTo rather than skip.

If the provided position is before the start boundary, the position will be set to the start boundary. If the provided position is after the end boundary, the position will be set to the end boundary. This is done to prevent the treewalker from traversing outside the boundaries.

Parameters

position : ViewPosition

Position to jump to.

Returns

void

Gets the next tree walker's value.

Returns

IteratorResult<ViewTreeWalkerValue, undefined>

Object implementing iterator interface, returning information about taken step.

Moves position in the direction skipping values as long as the callback function returns true.

For example:

walker.skip( value => value.type == 'text' ); // <p>{}foo</p> -> <p>foo[]</p>
walker.skip( value => true ); // Move the position to the end: <p>{}foo</p> -> <p>foo</p>[]
walker.skip( value => false ); // Do not move the position.

Parameters

skip : ( value: ViewTreeWalkerValue ) => boolean

Callback function. Gets ViewTreeWalkerValue and should return true if the value should be skipped or false if not.

Returns

void

Format returned data and adjust previousPosition and nextPosition if reach the bound of the ViewText.

Parameters

type : ViewTreeWalkerValueType

Type of step.

item : ViewItem

Item between old and new position.

previousPosition : ViewPosition

Previous position of iterator.

nextPosition : ViewPosition

Next position of iterator.

[ length ] : number

Length of the item.

Returns

IteratorYieldResult<ViewTreeWalkerValue>

Makes a step forward in view. Moves the position to the next position and returns the encountered value.

Returns

IteratorResult<ViewTreeWalkerValue, undefined>

Makes a step backward in view. Moves the position to the previous position and returns the encountered value.

Returns

IteratorResult<ViewTreeWalkerValue, undefined>