Context menu in ASP.NET CORE Gantt component

3 Jan 20248 minutes to read

The Gantt control allows you to perform quick actions by using context menu. When right-clicking the context menu, the context menu options are shown. To enable this feature, set the enableContextMenu to true. The default context menu options are enabled using the editSettings property. The context menu options can be customized using the contextMenuItems property.

The default items are listed in the following table.

Items Description
AutoFit Auto-fits the current column.
AutoFitAll Auto-fits all columns.
SortAscending Sorts the current column in ascending order.
SortDescending Sorts the current column in descending order.
TaskInformation Edits the current task.
Add Adds a new row to the Gantt.
Indent Indent the selected record to one level.
Outdent Outdent the selected record to one level.
DeleteTask Deletes the current task.
Save Saves the edited task.
Cancel Cancels the edited task.
DeleteDependency Deletes the current dependency task link.
Convert Converts current task to milestone or vice-versa. 
<ejs-gantt id='Gantt' dataSource="ViewBag.dataSource" height="450px" enableContextMenu="true" allowSorting="true" allowResizing="true">
        <e-gantt-taskfields id="TaskId" name="TaskName" startDate="StartDate"
            endDate="EndDate" duration="Duration" progress="Progress" child="SubTasks" dependency="Predecessor">
        </e-gantt-taskfields>
        <e-gantt-editsettings allowAdding="true" allowEditing="true" allowDeleting="true">
        </e-gantt-editsettings>
    </ejs-gantt>
public IActionResult Index()
{
    ViewBag.DataSource = GanttData.EditingData();	
    return View();
}

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Custom context menu items

The custom context menu items can be added by defining the contextMenuItems as a collection of [contextMenuItemModel]. Actions for the customized items can be defined in the contextMenuClick event and the visibility of customized items can be defined in the [contextMenuOpen] event.

To create custom context menu items for header area, define the target property as .e-gridheader.

The following sample shows context menu item for parent rows to expand or collapse child rows in the content area and a context menu item to hide columns in the header area.

@{
        List<object> contextItems = new List<object> { "AutoFitAll", "AutoFit", "TaskInformation", "DeleteTask", "Save", "Cancel",
    "SortAscending", "SortDescending", "Add", "DeleteDependency", "Convert"};

        contextItems.Add(new { text = "Collapse the Row", target = ".e-content", id = "collapserow" });
        contextItems.Add(new { text = "Expand the Row", target = ".e-content", id = "expandrow" });
        contextItems.Add(new { text = "Hide Column", target = ".e-gridheader", id = "hidecols" });

    }

    <ejs-gantt id='Gantt' dataSource="ViewBag.dataSource" height="450px" enableContextMenu="true" contextMenuItems="contextItems"
    allowSorting="true" allowResizing="true"  contextMenuOpen="contextMenuOpen" contextMenuClick="contextMenuClick" >
        <e-gantt-taskfields id="TaskId" name="TaskName" startDate="StartDate"
            endDate="EndDate" duration="Duration" progress="Progress" child="SubTasks" dependency="Predecessor">
        </e-gantt-taskfields>
        <e-gantt-editsettings allowAdding="true" allowEditing="true" allowDeleting="true">
        </e-gantt-editsettings>
    </ejs-gantt>

     <script>
        function contextMenuOpen(args) {
            var record = args.rowData;
            if (args.type !== 'Header') {
                if (!record.hasChildRecords) {
                    args.hideItems.push("Collapse the Row");
                    args.hideItems.push("Expand the Row");
                } else {
                    if(record.expanded){
                        args.hideItems.push("Expand the Row");                        
                    } else {
                        args.hideItems.push("Collapse the Row");
                    }
                }
            }
        }
            function contextMenuClick(args) {
                var ganttObj = document.getElementById("Gantt").ej2_instances[0];
                var record = args.rowData;
                if (args.item.id === 'collapserow') {
                    ganttObj.collapseByID(record.ganttProperties.taskId);
                }
                if (args.item.id === 'expandrow') {
                    ganttObj.expandByID(record.ganttProperties.taskId);
                }
                if (args.item.id === 'hidecols') {
                    ganttObj.hideColumn(args.column.headerText);
                }
        }
    </script>
public IActionResult Index()
{
    ViewBag.DataSource = GanttData.EditingData();	
    return View();
}

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NOTE

You can show an specific item in context menu for header/content area in the Gantt control by defining the target property.

Touch interaction

To perform long press action on a row, context menu is opened, and then tap a menu item to trigger its action.