How to use gantt with observable collection ?

[Joe Robe]

Hi,

I just modified the defualt gannt code by using an observable. However adding tasks do not show up in the chart. I also tried to call refresh, ti does not work either.

See code below:

@using Syncfusion.Blazor.Gantt

@using Syncfusion.Blazor.Data

@using Syncfusion.Blazor.Buttons

@using Syncfusion.Blazor

@using Syncfusion.Blazor.Popups

@using System.Collections.ObjectModel;

@page "/Foo"

<button @onclick="Add">Add</button><span>@TaskCollection?.Count</span>

<div class="col-lg-12 control-section">

<div class="content-wrapper">

<div class="row">

<SfGantt @ref="Gantt" DataSource="@TaskCollection" Height="450px" Width="100%" HighlightWeekends="true"

ProjectStartDate="@ProjectStart" ProjectEndDate="@ProjectEnd">

<GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress"

Dependency="Predecessor" ParentID="ParentId"></GanttTaskFields>

<GanttLabelSettings LeftLabel="TaskName" TValue="TaskData"> </GanttLabelSettings>

<GanttSplitterSettings Position="30%"> </GanttSplitterSettings>

</SfGantt>

</div>

</div>

</div>

@code{

public DateTime ProjectStart = new DateTime(2019, 3, 24);

public DateTime ProjectEnd = new DateTime(2019, 7, 6);

public ObservableCollection<TaskData> TaskCollection { get; set; }

public SfGantt<TaskData> Gantt { get; set; }

async Task Add()

{

var taskData = new TaskData()

{

TaskId = TaskCollection.Count + 1,

TaskName = "Added:" + TaskCollection.Count + 1,

StartDate = new DateTime(2019, 04, 02),

EndDate = new DateTime(2019, 04, 08),

Duration = "5days"

};

TaskCollection.Add(taskData);

await Gantt.Refresh();

}

protected override void OnInitialized()

{

this.TaskCollection = new ObservableCollection<TaskData>()

{

new TaskData() {

TaskId = 1,

TaskName = "Product concept ",

StartDate = new DateTime(2019, 04, 02),

EndDate = new DateTime(2019, 04, 08),

Duration = "5days"

},

new TaskData() {

TaskId = 2,

TaskName = "Defining the product usage",

StartDate = new DateTime(2019, 04, 02),

EndDate = new DateTime(2019, 04, 08),

Duration = "3",

Progress = 30,

ParentId = 1,

BaselineStartDate = new DateTime(2019, 04, 02),

BaselineEndDate = new DateTime(2019, 04, 02),

}

};

}

public class TaskData

{

public int TaskId { get; set; }

public string TaskName { get; set; }

public DateTime? StartDate { get; set; }

public DateTime? EndDate { get; set; }

public DateTime? BaselineStartDate { get; set; }

public DateTime? BaselineEndDate { get; set; }

public string Duration { get; set; }

public int Progress { get; set; }

public string Predecessor { get; set; }

public object ResourceId { get; set; }

public string Notes { get; set; }

public string TaskType { get; set; }

public int? ParentId { get; set; }

}

}

[Monisha Sivanthilingam]

Hi Joe, 

 

Greetings from Syncfusion support. 

 

We have analyzed your query and would like to suggest the AddRecord public method available in Gantt Chart to add a record to your Gantt Chart. The following code snippets demonstrate the solution. 

 

Index.razor 

 

public void Add() 

{ 

   var taskData = new TaskData() 

   { 

            TaskId = Convert.ToInt32(TaskCollection.Count) + 1, 

            TaskName = "Added:" + (Convert.ToInt32(TaskCollection.Count) + 1), 

            StartDate = new DateTime(2019, 04, 02), 

            EndDate = new DateTime(2019, 04, 08), 

            Duration = "5" 

   }; 

  this.Gantt.AddRecord(taskData, 1, RowPosition.Below); 

} 

 

 

We have prepared a sample  for your reference. 

 

Please contact us if you require any further assistance. 

 

Regards, 

Monisha. 

[Joe Robe]

Thanks, but it would be great if you actually would try you example :)

At first add , the count of the collection does not increase.

If you press add the second time, all data on the left side disappears and now the count goes up from 2 to 4 !

Clicking again nothing happens but count goes up to 6 ! More clicking does NOTHING

If add Gantt.Refresh() after ther add, the left data immediately disappers.

[Monisha Sivanthilingam]

Hi Joe, 

 

We were able to replicate the issue you reported. We will validate it and provide you with further details tomorrow(June 22,2021). 

 

We appreciate your patience until then. 

 

Regards, 

Monisha. 

[Monisha Sivanthilingam]

Hi Joe, 

 

Thank you for your patience. 

 

We have confirmed the issue with adding new records through the AddRecord method as a bug and have logged a bug report for it. You can track its status from the below feedback link. 

 

Feedback: https://www.syncfusion.com/feedback/26380/issue-when-adding-a-new-record-through-method 

 

The fix will be provided in the patch release scheduled for the second week of July, 2021. 

 

Regards, 

Monisha.