QueryBuilderColumn.Operators is null in Create event

Question

Unless you have assigned a List<ListModel> to the QueryBuilderColumn.Operators parameter its value is always null, even though the set of default operators is set on the column. Would it be possible to assign the default operator list to QueryBuilderColumn.Operators? Would be really helpful to have this available in the Create event to allow customisation of the available operators by columns. Currently we have to maintain copy of the list of the defaults operators by datatype and assign this to each column so its available in the Create event.

Mohan Kumar Ramasamy · Accepted Answer

Hi Michael, We have checked your requirement. We can set customize operator in Querybuilder Column tag. Please refer below code snippets. @code { SfQueryBuilder QueryBuilderObj; private void Created() { } public List Operators = new List { new OperatorsModel { Text="Equal", Value="equal"}, new OperatorsModel { Text="Not equal", Value="notequal"}, new OperatorsModel { Text="Greater than", Value="greaterthan"}, new OperatorsModel { Text="Less than", Value="lessthan"}, new OperatorsModel { Text="Less than or equal", Value="lessthanorequal"}, new OperatorsModel { Text="Greater than or equal", Value="greaterthanorequal"} }; public List customOperators = new List { new OperatorsModel { Text="Equal", Value="equal"}, new OperatorsModel { Text="Not equal", Value="notequal"} }; private string[] Values = new string[] { "Mr.", "Mrs." }; public class EmployeeDetails { public int EmployeeID { get; set; } public string FirstName { get; set; } public bool TitleOfCourtesy { get; set; } public string Title { get; set; } public DateTime HireDate { get; set; } public string Country { get; set; } public string City { get; set; } } } For your reference, we have prepared a sample based on this. Please refer below link. Link: https://www.syncfusion.com/downloads/support/forum/160562/ze/QuerybuilderWithOperator-1581066415 Operators UG Link: https://blazor.syncfusion.com/documentation/query-builder/columns-binding/#operators Please let us know, if you need any further assistance. Regards, Mohan kumar R

HappyCamper · Answer

Mohan,Your example above works great if you are hardcoding your QueryBuilderColumns.... However, your solution isn't viable if you are trying to create dynamic columns. In a dynamic column scenario, you would typically try to build your column ui as per the below: @foreach (DataGridColumn item in DataGridColumns) { } The foreach iterates some sort of list which provides the properties required to build the column. However, if you have a property of type List and try to assign it to the Operators property above, it does not work. How would you go about specifying the operators directly? Again, your sample above isn't viable as the operators are essentially still hardcoded and does not support a dynamic methodology. In essence you would want to be able to specify specific operators, per column... and each column could have its own custom operators. The number of columns are unknown until runtime.

Gayathri KarunaiAnandam · Answer

Hi HappyCamper,

We have checked your reported query. We have prepared a sample in which columns are created dynamically based on your requirement. We can add custom Operators to Querybuilder in Dynamic Columns. Please check the below code snippet.

<SfQueryBuilder TValue="ExpandoObject">

<QueryBuilderColumns>

@{

foreach(var column in columns)

{

<QueryBuilderColumn Field="@column.Field" Label="@column.Label" Type="@column.Type" Operators="@column.Operators"></QueryBuilderColumn>

}

</QueryBuilderColumns>

</SfQueryBuilder>

@code {

private List<QueryBuilderColumn> columns = new();

private static string[] Values = new string[] { "Mr.", "Mrs." };

public List<OperatorsModel> CustomOperators = new List<OperatorsModel> {

new OperatorsModel { Text="Equal", Value="equal"},

new OperatorsModel { Text="Not equal", Value="notequal"}

};

protected override async Task OnInitializedAsync()

{

columns = new List<QueryBuilderColumn>()

{

new QueryBuilderColumn(){ Field="EmployeeID", Label="Employee ID", Type=ColumnType.Number, Operators=CustomOperators},

new QueryBuilderColumn(){ Field="FirstName", Label="First Name", Type=ColumnType.String, Operators=CustomOperators},

new QueryBuilderColumn(){ Field="TitleOfCourtesy", Label="Title of Courtesy", Type=ColumnType.Boolean, Values=Values },

};

await base.OnInitializedAsync();

}

For your convenience, we have prepared a sample based on this. Please check the sample.

Sample: https://www.syncfusion.com/downloads/support/forum/160562/ze/Application-1775559597

Please get back to us, if you need further assistance.

Regards,

Gayathri K