Trilium Frontend API
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    Class ModelPosition

    Represents a position in the model tree.

    A position is represented by its module:engine/model/position~ModelPosition#root and a module:engine/model/position~ModelPosition#path in that root.

    You can create position instances via its constructor or the createPosition*() factory methods of module:engine/model/model~Model and module:engine/model/writer~ModelWriter.

    Note: Position is based on offsets, not indexes. This means that a position between two text nodes foo and bar has offset 3, not 1. See module:engine/model/position~ModelPosition#path for more information.

    Since a position in the model is represented by a module:engine/model/position~ModelPosition#root position root and module:engine/model/position~ModelPosition#path position path it is possible to create positions placed in non-existing places. This requirement is important for operational transformation algorithms.

    Also, module:engine/model/operation/operation~Operation operations kept in the module:engine/model/document~ModelDocument#history document history are storing positions (and ranges) which were correct when those operations were applied, but may not be correct after the document has changed.

    When changes are applied to the model, it may also happen that module:engine/model/position~ModelPosition#parent position parent will change even if position path has not changed. Keep in mind, that if a position leads to non-existing element, module:engine/model/position~ModelPosition#parent and some other properties and methods will throw errors.

    In most cases, position with wrong path is caused by an error in code, but it is sometimes needed, as described above.

    Hierarchy (View Summary)

    Index

    Constructors

    Properties

    path: readonly number[]

    Position of the node in the tree. Path contains offsets, not indexes.

    Position can be placed before, after or in a module:engine/model/node~ModelNode node if that node has module:engine/model/node~ModelNode#offsetSize greater than 1. Items in position path are module:engine/model/node~ModelNode#startOffset starting offsets of position ancestors, starting from direct root children, down to the position offset in it's parent.

    ROOT
    |- P before: [ 0 ] after: [ 1 ]
    |- UL before: [ 1 ] after: [ 2 ]
    |- LI before: [ 1, 0 ] after: [ 1, 1 ]
    | |- foo before: [ 1, 0, 0 ] after: [ 1, 0, 3 ]
    |- LI before: [ 1, 1 ] after: [ 1, 2 ]
    |- bar before: [ 1, 1, 0 ] after: [ 1, 1, 3 ]

    foo and bar are representing module:engine/model/text~ModelText text nodes. Since text nodes has offset size greater than 1 you can place position offset between their start and end:

    ROOT
    |- P
    |- UL
    |- LI
    | |- f^o|o ^ has path: [ 1, 0, 1 ] | has path: [ 1, 0, 2 ]
    |- LI
    |- b^a|r ^ has path: [ 1, 1, 1 ] | has path: [ 1, 1, 2 ]

    Root of the position path.

    Position stickiness. See module:engine/model/position~ModelPositionStickiness.

    Accessors

    • get index(): number

      Position module:engine/model/position~ModelPosition#offset offset converted to an index in position's parent node. It is equal to the module:engine/model/node~ModelNode#index index of a node after this position. If position is placed in text node, position index is equal to the index of that text node.

      Returns number

    • get isAtEnd(): boolean

      Is true if position is at the end of its module:engine/model/position~ModelPosition#parent parent, false otherwise.

      Returns boolean

    • get isAtStart(): boolean

      Is true if position is at the beginning of its module:engine/model/position~ModelPosition#parent parent, false otherwise.

      Returns boolean

    • get nodeAfter(): ModelNode

      Node directly after this position. Returns null if this position is at the end of its parent, or if it is in a text node.

      Returns ModelNode

    • get nodeBefore(): ModelNode

      Node directly before this position. Returns null if this position is at the start of its parent, or if it is in a text node.

      Returns ModelNode

    • get offset(): number

      Offset at which this position is located in its module:engine/model/position~ModelPosition#parent parent. It is equal to the last item in position module:engine/model/position~ModelPosition#path path.

      Returns number

    • set offset(newOffset: number): void

      Parameters

      • newOffset: number

      Returns void

    • Parent element of this position.

      Keep in mind that parent value is calculated when the property is accessed. If module:engine/model/position~ModelPosition#path position path leads to a non-existing element, parent property will throw error.

      Also it is a good idea to cache parent property if it is used frequently in an algorithm (i.e. in a long loop).

      Returns ModelElement | ModelDocumentFragment

    • get textNode(): ModelText

      Returns module:engine/model/text~ModelText text node instance in which this position is placed or null if this position is not in a text node.

      Returns ModelText

    Methods

    • Internal

      Returns a new position that is a combination of this position and given positions.

      The combined position is a copy of this position transformed by moving a range starting at source position to the target position. It is expected that this position is inside the moved range.

      Example:

      let original = model.createPositionFromPath( root, [ 2, 3, 1 ] );
      let source = model.createPositionFromPath( root, [ 2, 2 ] );
      let target = model.createPositionFromPath( otherRoot, [ 1, 1, 3 ] );
      original._getCombined( source, target ); // path is [ 1, 1, 4, 1 ], root is `otherRoot`

      Explanation:

      We have a position [ 2, 3, 1 ] and move some nodes from [ 2, 2 ] to [ 1, 1, 3 ]. The original position was inside moved nodes and now should point to the new place. The moved nodes will be after positions [ 1, 1, 3 ], [ 1, 1, 4 ], [ 1, 1, 5 ]. Since our position was in the second moved node, the transformed position will be in a sub-tree of a node at [ 1, 1, 4 ]. Looking at original path, we took care of [ 2, 3 ] part of it. Now we have to add the rest of the original path to the transformed path. Finally, the transformed position will point to [ 1, 1, 4, 1 ].

      Parameters

      Returns ModelPosition

      Combined position.

    • Internal

      Returns a copy of this position that is updated by removing howMany nodes starting from deletePosition. It may happen that this position is in a removed node. If that is the case, null is returned instead.

      Parameters

      • deletePosition: ModelPosition

        Position before the first removed node.

      • howMany: number

        How many nodes are removed.

      Returns ModelPosition

      Transformed position or null.

    • Internal

      Returns a copy of this position that is updated by inserting howMany nodes at insertPosition.

      Parameters

      • insertPosition: ModelPosition

        Position where nodes are inserted.

      • howMany: number

        How many nodes are inserted.

      Returns ModelPosition

      Transformed position.

    • Internal

      Returns a copy of this position transformed by an insert operation.

      Parameters

      Returns ModelPosition

    • Internal

      Returns a copy of this position transformed by merge operation.

      Parameters

      Returns ModelPosition

    • Internal

      Returns a copy of this position that is updated by moving howMany nodes from sourcePosition to targetPosition.

      Parameters

      • sourcePosition: ModelPosition

        Position before the first element to move.

      • targetPosition: ModelPosition

        Position where moved elements will be inserted.

      • howMany: number

        How many consecutive nodes to move, starting from sourcePosition.

      Returns ModelPosition

      Transformed position.

    • Internal

      Returns a copy of this position transformed by a move operation.

      Parameters

      Returns ModelPosition

    • Internal

      Returns a copy of this position transformed by a split operation.

      Parameters

      Returns ModelPosition

    • Returns a new position that is equal to current position.

      Returns this

    • Checks whether this position is before or after given position.

      This method is safe to use it on non-existing positions (for example during operational transformation).

      Parameters

      Returns ModelPositionRelation

    • Returns the parent element of the given name. Returns null if the position is not inside the desired parent.

      Parameters

      • parentName: string

        The name of the parent element to find.

      Returns ModelElement

    • Returns an module:engine/model/element~ModelElement or module:engine/model/documentfragment~ModelDocumentFragment which is a common ancestor of both positions. The #root roots of these two positions must be identical.

      Parameters

      Returns ModelElement | ModelDocumentFragment

    • Returns the slice of two position #path paths which is identical. The #root roots of these two paths must be identical.

      This method is safe to use it on non-existing positions (for example during operational transformation).

      Parameters

      Returns number[]

      The common path.

    • Gets the farthest position which matches the callback using module:engine/model/treewalker~ModelTreeWalker TreeWalker.

      For example:

      getLastMatchingPosition( value => value.type == 'text' );
      // <paragraph>[]foo</paragraph> -> <paragraph>foo[]</paragraph>

      getLastMatchingPosition( value => value.type == 'text', { direction: 'backward' } );
      // <paragraph>foo[]</paragraph> -> <paragraph>[]foo</paragraph>

      getLastMatchingPosition( value => false );
      // Do not move the position.

      Parameters

      • skip: (value: ModelTreeWalkerValue) => boolean

        Callback function. Gets module:engine/model/treewalker~ModelTreeWalkerValue and should return true if the value should be skipped or false if not.

      • Optionaloptions: ModelTreeWalkerOptions

        Object with configuration options. See module:engine/model/treewalker~ModelTreeWalker.

      Returns ModelPosition

      The position after the last item which matches the skip callback test.

    • Returns a path to this position's parent. Parent path is equal to position module:engine/model/position~ModelPosition#path path but without the last item.

      This method is safe to use it on non-existing positions (for example during operational transformation).

      Returns number[]

      Path to the parent.

    • Returns a new instance of Position, that has same #parent parent but it's offset is shifted by shift value (can be a negative value).

      This method is safe to use it on non-existing positions (for example during operational transformation).

      Parameters

      • shift: number

        Offset shift. Can be a negative value.

      Returns ModelPosition

      Shifted position.

    • Returns a copy of this position that is transformed by given operation.

      The new position's parameters are updated accordingly to the effect of the operation.

      For example, if n nodes are inserted before the position, the returned position ~ModelPosition#offset will be increased by n. If the position was in a merged element, it will be accordingly moved to the new element, etc.

      This method is safe to use it on non-existing positions (for example during operational transformation).

      Parameters

      • operation: Operation

        Operation to transform by.

      Returns ModelPosition

      Transformed position.

    • Checks if two positions are in the same parent.

      This method is safe to use it on non-existing positions (for example during operational transformation).

      Parameters

      Returns boolean

      true if positions have the same parent, false otherwise.

    • Checks whether the object is of type module:engine/model/node~ModelNode or its subclass.

      This method is useful when processing model objects that are of unknown type. For example, a function may return a module:engine/model/documentfragment~ModelDocumentFragment or a module:engine/model/node~ModelNode that can be either a text node or an element. This method can be used to check what kind of object is returned.

      someObject.is( 'element' ); // -> true if this is an element
      someObject.is( 'node' ); // -> true if this is a node (a text node or an element)
      someObject.is( 'documentFragment' ); // -> true if this is a document fragment

      Since this method is also available on a range of view objects, you can prefix the type of the object with model: or view: to check, for example, if this is the model's or view's element:

      modelElement.is( 'model:element' ); // -> true
      modelElement.is( 'view:element' ); // -> false

      By using this method it is also possible to check a name of an element:

      imageElement.is( 'element', 'imageBlock' ); // -> true
      imageElement.is( 'element', 'imageBlock' ); // -> same as above
      imageElement.is( 'model:element', 'imageBlock' ); // -> same as above, but more precise

      Parameters

      • type: "node" | "model:node"

      Returns this is ModelElement | ModelNode | ModelText | ModelRootElement

      NODE

    • Checks whether the object is of type module:engine/model/element~ModelElement or its subclass.

      element.is( 'element' ); // -> true
      element.is( 'node' ); // -> true
      element.is( 'model:element' ); // -> true
      element.is( 'model:node' ); // -> true

      element.is( 'view:element' ); // -> false
      element.is( 'documentSelection' ); // -> false

      Assuming that the object being checked is an element, you can also check its module:engine/model/element~ModelElement#name name:

      element.is( 'element', 'imageBlock' ); // -> true if this is an <imageBlock> element
      text.is( 'element', 'imageBlock' ); -> false

      Parameters

      • type: "element" | "model:element"

      Returns this is ModelElement | ModelRootElement

      ELEMENT

    • Checks whether the object is of type module:engine/model/rootelement~ModelRootElement.

      rootElement.is( 'rootElement' ); // -> true
      rootElement.is( 'element' ); // -> true
      rootElement.is( 'node' ); // -> true
      rootElement.is( 'model:rootElement' ); // -> true
      rootElement.is( 'model:element' ); // -> true
      rootElement.is( 'model:node' ); // -> true

      rootElement.is( 'view:element' ); // -> false
      rootElement.is( 'documentFragment' ); // -> false

      Assuming that the object being checked is an element, you can also check its module:engine/model/element~ModelElement#name name:

      rootElement.is( 'rootElement', '$root' ); // -> same as above
      

      Parameters

      • type: "rootElement" | "model:rootElement"

      Returns this is ModelRootElement

      ROOT_ELEMENT

    • Checks whether the object is of type module:engine/model/text~ModelText.

      text.is( '$text' ); // -> true
      text.is( 'node' ); // -> true
      text.is( 'model:$text' ); // -> true
      text.is( 'model:node' ); // -> true

      text.is( 'view:$text' ); // -> false
      text.is( 'documentSelection' ); // -> false

      Note: Until version 20.0.0 this method wasn't accepting '$text' type. The legacy 'text' type is still accepted for backward compatibility.

      Parameters

      • type: "$text" | "model:$text"

      Returns this is ModelText

      TEXT

    • Checks whether the object is of type module:engine/model/position~ModelPosition or its subclass.

      position.is( 'position' ); // -> true
      position.is( 'model:position' ); // -> true

      position.is( 'view:position' ); // -> false
      position.is( 'documentSelection' ); // -> false

      Parameters

      • type: "position" | "model:position"

      Returns this is ModelPosition | ModelLivePosition

      POSITION

    • Checks whether the object is of type module:engine/model/liveposition~ModelLivePosition.

      livePosition.is( 'position' ); // -> true
      livePosition.is( 'model:position' ); // -> true
      livePosition.is( 'liveposition' ); // -> true
      livePosition.is( 'model:livePosition' ); // -> true

      livePosition.is( 'view:position' ); // -> false
      livePosition.is( 'documentSelection' ); // -> false

      Parameters

      • type: "livePosition" | "model:livePosition"

      Returns this is ModelLivePosition

      LIVE_POSITION

    • Checks whether the object is of type module:engine/model/range~ModelRange or its subclass.

      range.is( 'range' ); // -> true
      range.is( 'model:range' ); // -> true

      range.is( 'view:range' ); // -> false
      range.is( 'documentSelection' ); // -> false

      Parameters

      • type: "range" | "model:range"

      Returns this is ModelRange | ModelLiveRange

      RANGE

    • Checks whether the object is of type module:engine/model/liverange~ModelLiveRange.

      liveRange.is( 'range' ); // -> true
      liveRange.is( 'model:range' ); // -> true
      liveRange.is( 'liveRange' ); // -> true
      liveRange.is( 'model:liveRange' ); // -> true

      liveRange.is( 'view:range' ); // -> false
      liveRange.is( 'documentSelection' ); // -> false

      Parameters

      • type: "liveRange" | "model:liveRange"

      Returns this is ModelLiveRange

      LIVE_RANGE

    • Checks whether the object is of type module:engine/model/documentfragment~ModelDocumentFragment.

      docFrag.is( 'documentFragment' ); // -> true
      docFrag.is( 'model:documentFragment' ); // -> true

      docFrag.is( 'view:documentFragment' ); // -> false
      docFrag.is( 'element' ); // -> false
      docFrag.is( 'node' ); // -> false

      Parameters

      • type: "documentFragment" | "model:documentFragment"

      Returns this is ModelDocumentFragment

      DOCUMENT_FRAGMENT

    • Checks whether the object is of type module:engine/model/selection~ModelSelection or module:engine/model/documentselection~ModelDocumentSelection.

      selection.is( 'selection' ); // -> true
      selection.is( 'model:selection' ); // -> true

      selection.is( 'view:selection' ); // -> false
      selection.is( 'range' ); // -> false

      Parameters

      • type: "selection" | "model:selection"

      Returns this is ModelSelection | ModelDocumentSelection

      SELECTION

    • Checks whether the object is of type module:engine/model/documentselection~ModelDocumentSelection.

      selection.is( 'selection' ); // -> true
      selection.is( 'documentSelection' ); // -> true
      selection.is( 'model:selection' ); // -> true
      selection.is( 'model:documentSelection' ); // -> true

      selection.is( 'view:selection' ); // -> false
      selection.is( 'element' ); // -> false
      selection.is( 'node' ); // -> false

      Parameters

      • type: "documentSelection" | "model:documentSelection"

      Returns this is ModelDocumentSelection

      DOCUMENT_SELECTION

    • Checks whether the object is of type module:engine/model/markercollection~Marker.

      marker.is( 'marker' ); // -> true
      marker.is( 'model:marker' ); // -> true

      marker.is( 'view:element' ); // -> false
      marker.is( 'documentSelection' ); // -> false

      Parameters

      • type: "marker" | "model:marker"

      Returns this is Marker

      MARKER

    • Checks whether the object is of type module:engine/model/textproxy~ModelTextProxy.

      textProxy.is( '$textProxy' ); // -> true
      textProxy.is( 'model:$textProxy' ); // -> true

      textProxy.is( 'view:$textProxy' ); // -> false
      textProxy.is( 'range' ); // -> false

      Note: Until version 20.0.0 this method wasn't accepting '$textProxy' type. The legacy 'textProxt' type is still accepted for backward compatibility.

      Parameters

      • type: "$textProxy" | "model:$textProxy"

      Returns this is ModelTextProxy

      TEXT_PROXY

    • Checks whether the object is of type module:engine/model/element~ModelElement or its subclass and has the specified name.

      element.is( 'element', 'imageBlock' ); // -> true if this is an <imageBlock> element
      text.is( 'element', 'imageBlock' ); -> false

      Type Parameters

      • N extends string

      Parameters

      • type: "element" | "model:element"
      • name: N

      Returns this is (ModelElement | ModelRootElement) & { name: N }

      ELEMENT_NAME

    • Checks whether the object is of type module:engine/model/rootelement~ModelRootElement and has the specified name.

      rootElement.is( 'rootElement', '$root' );
      

      Type Parameters

      • N extends string

      Parameters

      • type: "rootElement" | "model:rootElement"
      • name: N

      Returns this is ModelRootElement & { name: N }

      ROOT_ELEMENT_NAME

    • Checks whether this position is after given position.

      This method is safe to use it on non-existing positions (for example during operational transformation).

      Parameters

      Returns boolean

      True if this position is after given position.

      module:engine/model/position~ModelPosition#isBefore

    • Checks whether this position is before given position.

      Note: watch out when using negation of the value returned by this method, because the negation will also be true if positions are in different roots and you might not expect this. You should probably use a.isAfter( b ) || a.isEqual( b ) or !a.isBefore( p ) && a.root == b.root in most scenarios. If your condition uses multiple isAfter and isBefore checks, build them so they do not use negated values, i.e.:

      if ( a.isBefore( b ) && c.isAfter( d ) ) {
      // do A.
      } else {
      // do B.
      }

      or, if you have only one if-branch:

      if ( !( a.isBefore( b ) && c.isAfter( d ) ) {
      // do B.
      }

      rather than:

      if ( !a.isBefore( b ) || && !c.isAfter( d ) ) {
      // do B.
      } else {
      // do A.
      }

      This method is safe to use it on non-existing positions (for example during operational transformation).

      Parameters

      Returns boolean

      True if this position is before given position.

    • Checks whether this position is equal to given position.

      This method is safe to use it on non-existing positions (for example during operational transformation).

      Parameters

      Returns boolean

      True if positions are same.

    • Checks whether this position is touching given position. Positions touch when there are no text nodes or empty nodes in a range between them. Technically, those positions are not equal but in many cases they are very similar or even indistinguishable.

      Parameters

      Returns boolean

      True if positions touch.

    • Checks whether the position is valid in current model tree, that is whether it points to an existing place in the model.

      Returns boolean

    • Returns unknown

    • Internal

      Creates position at the given location. The location can be specified as:

      • a module:engine/model/position~ModelPosition position,
      • parent element and offset (offset defaults to 0),
      • parent element and 'end' (sets position at the end of that element),
      • module:engine/model/item~ModelItem model item and 'before' or 'after' (sets position before or after given model item).

      This method is a shortcut to other factory methods such as:

      • module:engine/model/position~ModelPosition._createBefore,
      • module:engine/model/position~ModelPosition._createAfter.

      Parameters

      Returns ModelPosition

    • Creates a Position instance from given plain object (i.e. parsed JSON string).

      Parameters

      • json: any

        Plain object to be converted to Position.

      • doc: ModelDocument

        Document object that will be position owner.

      Returns ModelPosition

      Position instance created using given plain object.