Filter Lookup Editor Data Source

• Nov 17, 2020
• 2 minutes to read

This lesson explains how to filter data displayed in a lookup editor. This editor is used in the Detail Views for reference properties and contains a list of objects of another related class.

Note

Before you proceed, take a moment to review the following lessons:

• Inherit from the Business Class Library Class (XPO)
• Implement Custom Business Classes and Reference Properties (XPO)
• Implement Dependent Reference Properties (XPO)
• Set a Many-to-Many Relationship (XPO)

Step-by-Step Instructions

1. Specify a Many-to-Many relationship between the Position and Department classes. For more information, refer to the Set a Many-to-Many Relationship (XPO) lesson.

   C#

   [DefaultClassOptions]
   [System.ComponentModel.DefaultProperty(nameof(Title))]
    public class Department : BaseObject {
      //...
      [Association("Departments-Positions")]
      public XPCollection<Position> Positions {
         get { return GetCollection<Position>(nameof(Positions)); }
      }
   }
   
   [DefaultClassOptions]
   [System.ComponentModel.DefaultProperty(nameof(Title))]
   public class Position : BaseObject {
         //...
      [Association("Departments-Positions")]
      public XPCollection<Department> Departments {
         get { return GetCollection<Department>(nameof(Departments)); }
      }
   }
   

2. In the MySolution.Module project, open the “Model.DesignedDiffs.xafml” file in the Model Editor. Navigate to the BOModel | MySolution.Module.BusinessObjects node. Expand the Contact child node and select the Position child node.

   Set the node properties as follows:

   • Set the DataSourceProperty property to Department.Positions.
   • Set the DataSourcePropertyIsNullMode property to SelectAll.

   

3. Replace the Department property declaration with the following code:

   C#

   [Association("Department-Contacts", typeof(Department)), ImmediatePostData]
   public Department Department {
      get {return department;}
      set {
         SetPropertyValue(nameof(Department), ref department, value);
         // Clear Position and Manager properties if the Department has been changed.
         if(!IsLoading) {
            Position = null;
            if(Manager != null && Manager.Department != value) {
               Manager = null;
            }
         }
      }
   }
   

4. Run the application. Specify the Positions property for Department objects. Invoke a Contact Detail View. The Position editor dropdown lists Positions assigned to the Department object:

   

    

   

Detailed Explanation

In step 2, you specify the following:

• The Position lookup editor displays the Department.Positions collection.
• The Position lookup editor displays all existing objects in the Contact.Position editor when the Department.Positions property is not specified.

Next Lesson

Format a Property Value