A Link is a graphical user interface that allows the user to select one item from a list. The user opens the drop-down list and clicks inside the list on an item to select it. The Link is populated with data that exists in a different collection. The data can reside within the current application or within any application that is accessible from the current account. The Link differs from the regular Combo Box in that it stores a reference to the data from the linked collection, rather than a copy of the data. If the linked data changes, the relationship will still be maintained. For example, let's say you have a Sales Order field with a Link for selecting the customer based on the customer's name which is linked from the Customer collection. If the customer changes their name after the Sales Order is created (the linked customer record is modified), the Sales Order will still link to the correct (modified) customer record.

Adding a Link to the Form

1. In the Edit Form canvas, drag the from Form Widget palette onto the form canvas. A new link widget field is added in the canvas.
   
2. Enter a Label for the link widget. Notice that the Data Field associated with the widget is now populated with the label name but without spaces. You can tell that a field is a link field by looking at the small symbol within the field icon, other types of data fields will have an icon without the symbol inside.
   
   The Data Field should not contain any spaces and should be a unique name within the Collection.
3. The Properties section of the Form Editor will allow you to customize the data properties of your widget.
   
4. Click on the button to the right of Linked Collection to select the collection which the link widget will reference. Link widgets can reference a collection in any of the applications in the current account.
   
   Click on a collection from the Select Collection window and hit Select.
5. Once you establish a linked collection you can define the field that the link widget will use for its display value. Click on the button next to Display Field.
   
6. Click on a field to select it. The location of the field you selected will be displayed in the Properties section of the Form Editor.
   
7. Filtering criteria can be defined in the Filter and Sort window, which can be accessed by clicking on the button next to Filter.
   
8. The Link by reference checkbox automatically updates the link widget if the referenced value is changed. For example, if the link widget is displaying a client name and the name of the client changes the link will automatically be updated in existing records. If this checkbox is not checked, existing records will keep the old client name.
9. The Required Field radio button allows you to determine if the field needs to be filled out before a user is able to save the record. If the field is marked as a required field, it will be designated with a red asterisk (*) in the form.
10. The Display this field in the default collection view checkbox allows you to add this field as a column in the collection tab's view without having to enter the View Editor.
11. Display properties for the link widget can be set by clicking on the Widget tab in the Properties section of the Form Editor.
    
    
13. From the Number of rows to display menu drop down you can define how many options will be displayed in the link widget before the user has to use the scroll bar.
    
14. The Advanced Filter option allows users to search for a specific option based on keyword.
15. Authors can define advanced Conditional Style by clicking on the icon next to Condition Style.
    
16. In the Edit Form canvas, save your changes. Refer to the section on Version Management for more information.
17. Click Exit to return to the Collection page.