Cannot get child properties in TreeGrid column templates
Hi Alessandro,
Thanks for contacting syncfusion forum.
Query: I expect to see the third column (the one with the template) with the values "testString1", but I only see "String not found!". How can I solve this problem?
We checked your shared sample; we were able to reproduce the issue at our end. In your shared sample, the child value (ActualType) is always got null. So this issue occurred.
To avoid this issue, we suggest you follow the below code example,
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Your code:
<SfTreeGrid DataSource="@TreeData" IdMapping="TaskId" ParentIdMapping="ParentId" TreeColumnIndex="0"> ….. <TreeGridColumn HeaderText="Child String" Width="30" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Center"> <Template> @{ BusinessObject bo = context as BusinessObject;
if(bo is not null) { // The following line does not work, bo.AnyChild is not correctly recognized as an instance of MyFirstChildClass if (bo.AnyChild is MyFirstChildClass c1) { @c1.MyFirstChildString; } // The following line does not work, bo.AnyChild is not correctly recognized as an instance of MyChildClass else if(bo.AnyChild is MySecondChildClass c2) { @c2.MySecondChildString; } else { @:<span>String not found!</span> } } } </Template> </TreeGridColumn> </TreeGridColumns> </SfTreeGrid>
@code { public class MyParentClass { public string ActualType; }
public class MyFirstChildClass : MyParentClass { public string MyFirstChildString { get; set; } }
public class MySecondChildClass : MyParentClass { public string MySecondChildString { get; set; } }
…
Modified Code:
<SfTreeGrid DataSource="@TreeData" IdMapping="TaskId" ParentIdMapping="ParentId" TreeColumnIndex="0"> ….. TextAlign="Syncfusion.Blazor.Grids.TextAlign.Center"> <Template> @{ BusinessObject bo = context as BusinessObject;
if(bo.AnyChild is not null) { // The following line does not work, bo.AnyChild is not correctly recognized as an instance of MyFirstChildClass if (bo.AnyChild.ActualType == "MyFirstChildClass" ) {
@bo.AnyChild.MyFirstChildString; } // The following line does not work, bo.AnyChild is not correctly recognized as an instance of MyChildClass else if(bo.AnyChild.ActualType == "MySecondChildClass") { @bo.AnyChild.MySecondChildString; } else { @:<span>String not found!</span> } // @bo.AnyChild.ActualType; } } </Template> </TreeGridColumn> </TreeGridColumns> </SfTreeGrid>
@code { public class MyParentClass { public string? ActualType { get; set; } public string? MyFirstChildString { get; set; } public string? MySecondChildString { get; set; }
}
public class MyFirstChildClass : MyParentClass { public string? MyFirstChildString1 { get; set; } }
public class MySecondChildClass : MyParentClass { public string? MySecondChildString1 { get; set; } } … |
Please refer to the below screenshot,
Please refer to the below modified sample,
https://www.syncfusion.com/downloads/support/directtrac/general/ze/TreeGridDemo-1636130135
Kindly get back to us for further assistance.
Regards,
Pon selva
Hi Alessandro,
We appreciate your patience.
Upon on validation, we could see that source level fixing is not feasible for the reported issue. Since tree grid doesn’t know the information of the extended classes, the tree grid will know only the properties of BusinessObject class(data source class). And in BusinessObject class you have defined the sub class as MyParentClass in that you have defined only ActualType from that we cannot retrieve all the extended class properties.
So, we suggest you define the properties in MyParentClass and since its not work in your case because of many children definition. Hence, we suggest you use the ExpandoObject class as like below,
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<SfTreeGrid DataSource="@TreeData" IdMapping="TaskId" ParentIdMapping="ParentId" TreeColumnIndex="0"> <TreeGridColumns> ………………………………….. <Template> @{ BusinessObject bo = context as BusinessObject;
if (bo is not null) {
if (bo.AnyChild is ExpandoObject) { var data = (bo.AnyChild as IDictionary<string, object>); if ((bo.AnyChild as IDictionary<string, object>)["ActualType"].ToString() == "MyFirstChildClass") { @((bo.AnyChild as IDictionary<string, object>)["MyFirstChildString"]); } else if ((bo.AnyChild as IDictionary<string, object>)["ActualType"].ToString() == "MySecondChildClass") { @((bo.AnyChild as IDictionary<string, object>)["MySecondChildString"]); } else { @:<span>String not found!</span> } } } } </Template> </TreeGridColumn> </TreeGridColumns> </SfTreeGrid>
@code {
public class BusinessObject { public string TaskId { get; set; } public string TaskName { get; set; } public string? ParentId { get; set; } public ExpandoObject AnyChild { get; set; } }
public List<BusinessObject> TreeData = new List<BusinessObject>();
protected override void OnInitialized() { dynamic Task1 = new ExpandoObject(); Task1.ActualType = "MyFirstChildClass"; Task1.MyFirstChildString = "testString1";
dynamic Task2 = new ExpandoObject(); Task2.ActualType = "MySecondChildClass"; Task2.MySecondChildString = "testString2";
TreeData.Add(new BusinessObject() { TaskId = "1", TaskName = "Parent Task 1", ParentId = null, AnyChild = Task1 }); TreeData.Add(new BusinessObject() { TaskId = "2", TaskName = "Child task 1", ParentId = "1", AnyChild = Task2 }); } } |
Output
Kindly get back to us if you need any further assistance. We will be happy to assist you.
Regards,
Manivannan Padmanaban
