aspnet-402171-components-diagram-restrict-edit-operations.md
The ASPxDiagram control allows you to restrict edit operations in the following ways.
Set the corresponding Allow{Operation} property to false to prohibit an edit operation.
<dx:ASPxDiagram ID="Diagram" runat="server" Width="100%" Height="600px">
<SettingsEditing
AllowAddShape="false"
AllowChangeConnection="false"
AllowChangeConnectorPoints="false"
AllowChangeConnectorText="false"
AllowChangeShapeText="false"
AllowDeleteConnector="false"
AllowDeleteShape="false"
AllowMoveShape="false"
AllowResizeShape="false" />
</dx:ASPxDiagram>
Every time a user attempts an edit operation, the control raises the RequestEditOperation event. Use the allowed parameter to either permit or cancel the user action. To identify the operation type and target element, use the event parameters listed below.
The operation parameter identifies the edit operation. Note that if an Allow{Operation} property is set to false, the event does not fire for this operation. The table below lists all available operations.
The args parameter contains information about the shape or connector that takes part in the edit operation. The parameter’s value type depends on the operation type.
The reason parameter specifies whether the event responds to a user action or requests instruction on related UI command availability.
function onRequestEditOperation(s, e) {
if(e.operation === DiagramEditOperation.AddShape) {
if(e.args.shape.type !== "employee" && e.args.shape.type !== "team") {
if(e.reason !== DiagramRequestEditOperationReason.CheckUIElementAvailability)
showWarning("You can add only a 'Team' or an 'Employee' shape.");
e.allowed = false;
}
}
else if(e.operation === DiagramEditOperation.ResizeShape) {
if(e.args.newSize.width < 1 || e.args.newSize.height < 0.75) {
if(e.reason !== DiagramRequestEditOperationReason.CheckUIElementAvailability)
showWarning("The shape size is too small.");
e.allowed = false;
}
}
else if(e.operation === DiagramEditOperation.BeforeChangeShapeText) {
if(e.args.shape.type === "root") {
if(e.reason !== DiagramRequestEditOperationReason.CheckUIElementAvailability)
showWarning("You cannot change the 'Development' shape's text.");
e.allowed = false;
}
}
else if(e.operation === DiagramEditOperation.ChangeShapeText) {
if(e.args.text === "") {
if(e.reason !== DiagramRequestEditOperationReason.CheckUIElementAvailability)
showWarning("A shape's text cannot be empty.");
e.allowed = false;
}
}
...
}
<dx:ASPxDiagram ID="Diagram" runat="server" Width="100%" Height="600px">
<ClientSideEvents RequestEditOperation="onRequestEditOperation" />
</dx:ASPxDiagram>
Run Demo: Editing Restrictions
Set the ReadOnly property to true to protect the ASPxDiagram control from edit operations. In this mode, the control hides its UI elements: the toolbox, history toolbar, and properties panel.
<dx:ASPxDiagram ID="Diagram" runat="server" Width="100%" Height="600px" ReadOnly="true">
</dx:ASPxDiagram>