DiagramItem.Query Method

Returns the items that can be reached from this item by following the path specified in the given query expression.

Namespace: MindFusion.Diagramming.Wpf
Assembly: MindFusion.Diagramming.Wpf

 Syntax

C#

public DiagramItemCollection Query (
    string query
)

Visual Basic

Public Function Query( _
    query As String _
) As DiagramItemCollection

 Parameters

query

A query expression consisting of selectors and boolean predicates.

 Return Value

A collection of the found items.

 Remarks

The query string consists of selectors, where each selector specifies the next items that should be selected starting from the current one.

The following selectors can be applied to a node:

links	Selects all links connected to the current node
inlinks	Selects the incoming links of the current node
outlinks	Selects the outgoing links of the current node
parent	Selects the parent item of the current node if it is in a group
children	Selects the child nodes of the current node if it is in a group

The following selectors can be applied to a link:

nodes	Selects the two nodes connected by the current link
origin	Selects the Origin node of the current link
destination	Selects the Destination node of the current link
children	Selects the child nodes of the current link if it is in a group.

Selectors must be separated by the / character. The results returned by a selector can be also filtered using a predicate expression, enclosed in square brackets after the selector name. The predicate expression can include C# like boolean and arithmetic operators, and one of the following property identifiers:

tag	Returns the value of the Tag property.
text	Returns the value of the Text property.
weight	Returns the value of the Weight property.

 Example

The following code selects nodes two levels below the current one in a tree or layered graph.

C#

DiagramItemCollection items = diagram.ActiveItem.Query(
    "outlinks/destination/outlinks/destination");
diagram.Selection.Clear();
foreach (DiagramItem item in items)
    item.Selected = true;

The following code finds the neighbors of the currently selected node that can be reached from it by following links with Weight greater than 3.

C#

DiagramItemCollection items = diagram.ActiveItem.Query(
    "outlinks[weight>3]/destination");

The following example finds the destination nodes of links labeled "exception" going out of children of the current node's group.

C#

DiagramItemCollection items = diagram.ActiveItem.Query(
    "children/outlinks[text==\"exception\"]/destination");