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Immutable Mode in Angular Gantt Chart Component
1 Feb 202623 minutes to read
Immutable mode optimizes the Angular Gantt Chart component’s rendering performance by minimizing unnecessary re-renders, ideal for large projects with hundreds of tasks or frequent updates like real-time progress tracking. When enabled via the enableImmutableMode property, the component uses object reference comparison to identify changed tasks, re-rendering only modified or new rows while preserving unchanged rows’ DOM elements. This reduces DOM operations, CPU usage, and rendering time, ensuring smooth interactions for complex hierarchies or batch updates. For example, updating a single task’s progress in a 1,000-task project re-renders only that task’s row, significantly improving performance over standard mode, which re-renders all visible rows.
Configure immutable mode
Immutable mode requires a unique primary key in the data source, configured via the isPrimaryKey property, and valid taskFields mappings (e.g., id to a unique field like TaskID). The component compares object references to detect changes, requiring immutable data patterns where updates create new objects rather than mutating existing ones. Hierarchical task updates (e.g., parent-child tasks) are efficiently handled by checking only changed references, preserving nested structures.
Configuration requirements
-
Primary key: Set
isPrimaryKeyto true on a unique column (e.g., TaskID) to ensure accurate change detection. -
Unique identifiers: Assign stable, unique IDs to all tasks via
taskFields.id. - Immutable data: Create new objects for updates (e.g., { …task, progress: 50 }) to trigger reference changes.
The following example enables immutable mode:
import { Component, ViewEncapsulation, OnInit } from '@angular/core';
import { GanttModule,DayMarkersService, ToolbarItem, EditSettingsModel } from '@syncfusion/ej2-angular-gantt';
import { projectNewData } from './data';
@Component({
imports: [GanttModule],
providers: [DayMarkersService],
standalone: true,
selector: 'app-root',
template:
`<ejs-gantt id="ganttDefault" height="430px" [dataSource]="data" [taskFields]="taskSettings" [editSettings]="editSettings"
[toolbar]="toolbar" enableImmutableMode="true"></ejs-gantt>`,
encapsulation: ViewEncapsulation.None
})
export class AppComponent implements OnInit {
public data?: object[];
public taskSettings?: object;
public editSettings?: EditSettingsModel;
public toolbar?: ToolbarItem[];
public ngOnInit(): void {
this.data = projectNewData;
this.taskSettings = {
id: 'TaskID',
name: 'TaskName',
startDate: 'StartDate',
endDate: 'EndDate',
duration: 'Duration',
progress: 'Progress',
dependency: 'Predecessor',
child: 'subtasks'
};
this.editSettings = {
allowAdding: true,
allowEditing: true,
allowDeleting: true,
allowTaskbarEditing: true,
showDeleteConfirmDialog: true
};
this.toolbar = ['Add', 'Edit', 'Delete', 'Update', 'Cancel', 'Indent', 'Outdent'];
}
}import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));export let projectNewData: Object[] = [
{
TaskID: 1,
TaskName: 'Product Concept',
StartDate: new Date('04/02/2019'),
EndDate: new Date('04/21/2019'),
subtasks: [
{ TaskID: 2, TaskName: 'Defining the product and its usage', StartDate: new Date('04/02/2019'), Duration: 3, Progress: 30 },
{ TaskID: 3, TaskName: 'Defining target audience', StartDate: new Date('04/02/2019'), Duration: 3 },
{
TaskID: 4, TaskName: 'Prepare product sketch and notes', StartDate: new Date('04/02/2019'), Duration: 2,
Predecessor: '2', Progress: 30
},
]
},
{
TaskID: 5, TaskName: 'Concept Approval', StartDate: new Date('04/02/2019'), Duration: 0, Predecessor: '3,4',
Indicators: [
{
'date': '04/10/2019',
'name': '#briefing',
'title': 'Product concept breifing',
}
]
},
{
TaskID: 6,
TaskName: 'Market Research',
StartDate: new Date('04/02/2019'),
EndDate: new Date('04/21/2019'),
subtasks: [
{
TaskID: 7,
TaskName: 'Demand Analysis',
StartDate: new Date('04/04/2019'),
EndDate: new Date('04/21/2019'),
subtasks: [
{
TaskID: 8, TaskName: 'Customer strength', StartDate: new Date('04/04/2019'), Duration: 4,
Predecessor: '5', Progress: 30
},
{ TaskID: 9, TaskName: 'Market opportunity analysis', StartDate: new Date('04/04/2019'), Duration: 4, Predecessor: '5' }
]
},
{
TaskID: 10, TaskName: 'Competitor Analysis', StartDate: new Date('04/04/2019'), Duration: 4,
Predecessor: '7, 8', Progress: 30
},
{ TaskID: 11, TaskName: 'Product strength analsysis', StartDate: new Date('04/04/2019'), Duration: 4, Predecessor: '9' },
{
TaskID: 12, TaskName: 'Research complete', StartDate: new Date('04/04/2019'), Duration: 0, Predecessor: '10',
Indicators: [
{
'date': '04/20/2019',
'name': '#meeting',
'title': '1st board of directors meeting',
}
]
}
]
},
{
TaskID: 13,
TaskName: 'Product Design and Development',
StartDate: new Date('04/04/2019'),
EndDate: new Date('04/21/2019'),
subtasks: [
{
TaskID: 14, TaskName: 'Functionality design', StartDate: new Date('04/04/2019'),
Duration: 3, Progress: 30, Predecessor: '12'
},
{ TaskID: 15, TaskName: 'Quality design', StartDate: new Date('04/04/2019'), Duration: 3, Predecessor: '12' },
{ TaskID: 16, TaskName: 'Define Reliability', StartDate: new Date('04/04/2019'), Duration: 2, Progress: 30, Predecessor: '15' },
{ TaskID: 17, TaskName: 'Identifying raw materials', StartDate: new Date('04/04/2019'), Duration: 2, Predecessor: '15' },
{
TaskID: 18,
TaskName: 'Define cost plan',
StartDate: new Date('04/04/2019'),
EndDate: new Date('04/21/2019'),
subtasks: [
{
TaskID: 19, TaskName: 'Manufacturing cost', StartDate: new Date('04/04/2019'),
Duration: 2, Progress: 30, Predecessor: '17'
},
{ TaskID: 20, TaskName: 'Selling cost', StartDate: new Date('04/04/2019'), Duration: 2, Predecessor: '17' }
]
},
{
TaskID: 21,
TaskName: 'Development of the final design',
StartDate: new Date('04/04/2019'),
EndDate: new Date('04/21/2019'),
subtasks: [
{
TaskID: 22, TaskName: 'Defining dimensions and package volume', StartDate: new Date('04/04/2019'),
Duration: 2, Progress: 30, Predecessor: '19,20'
},
{
TaskID: 23, TaskName: 'Develop design to meet industry standards', StartDate: new Date('04/04/2019'),
Duration: 2, Predecessor: '22'
},
{ TaskID: 24, TaskName: 'Include all the details', StartDate: new Date('04/04/2019'), Duration: 3, Predecessor: '23' }
]
},
{
TaskID: 25, TaskName: 'CAD Computer-aided design', StartDate: new Date('04/04/2019'),
Duration: 3, Progress: 30, Predecessor: '24'
},
{ TaskID: 26, TaskName: 'CAM Computer-aided manufacturing', StartDate: new Date('04/04/2019'), Duration: 3, Predecessor: '25' },
{
TaskID: 27, TaskName: 'Design complete', StartDate: new Date('04/04/2019'), Duration: 0, Predecessor: '26',
Indicators: [
{
'date': '05/18/2019',
'name': '#meeting',
'title': '2nd board of directors meeting',
}
]
}
]
},
{ TaskID: 28, TaskName: 'Prototype Testing', StartDate: new Date('04/04/2019'), Duration: 4, Progress: 30, Predecessor: '27' },
{ TaskID: 29, TaskName: 'Include feedback', StartDate: new Date('04/04/2019'), Duration: 4, Predecessor: '28ss' },
{ TaskID: 30, TaskName: 'Manufacturing', StartDate: new Date('04/04/2019'), Duration: 5, Progress: 30, Predecessor: '28,29' },
{ TaskID: 31, TaskName: 'Assembling materials to finsihed goods', StartDate: new Date('04/04/2019'), Duration: 5, Predecessor: '30' },
{
TaskID: 32,
TaskName: 'Feedback and Testing',
StartDate: new Date('04/04/2019'),
EndDate: new Date('04/21/2019'),
subtasks: [
{
TaskID: 33, TaskName: 'Internal testing and feedback', StartDate: new Date('04/04/2019'),
Duration: 3, Progress: 45, Predecessor: '31'
},
{
TaskID: 34, TaskName: 'Customer testing and feedback', StartDate: new Date('04/04/2019'),
Duration: 3, Progress: 50, Predecessor: '33'
}
]
},
{
TaskID: 35,
TaskName: 'Final Product Development',
StartDate: new Date('04/04/2019'),
EndDate: new Date('04/21/2019'),
subtasks: [
{
TaskID: 36, TaskName: 'Important improvements', StartDate: new Date('04/04/2019'),
Duration: 4, Progress: 30, Predecessor: '34'
},
{
TaskID: 37, TaskName: 'Address any unforeseen issues', StartDate: new Date('04/04/2019'),
Duration: 4, Progress: 30, Predecessor: '36ss'
}
]
},
{
TaskID: 38,
TaskName: 'Final Product',
StartDate: new Date('04/04/2019'),
EndDate: new Date('04/21/2019'),
subtasks: [
{ TaskID: 39, TaskName: 'Branding product', StartDate: new Date('04/04/2019'), Duration: 4, Predecessor: '37' },
{
TaskID: 40, TaskName: 'Marketing and presales', StartDate: new Date('04/04/2019'),
Duration: 4, Progress: 30, Predecessor: '39'
}
]
}
];Feature compatibility and limitations
Immutable mode is incompatible with certain features due to its reference-based change detection:
-
Column reordering: Conflicts with reference tracking, requiring temporary disabling of
enableImmutableMode. - Virtualization: Incompatible with enableVirtualization, as both optimize rendering differently; choose based on dataset size.
For small datasets, standard rendering may suffice. For dynamic column operations, disable immutable mode temporarily. While immutable mode reduces rendering time, it may increase memory usage to maintain object references, a trade-off to consider for extremely large projects.