You use a collection rule when you want to hide or display columns in a dynamic table, assuming that certain conditions are met at runtime.

1. Open the page you want to configure, and then click Configure Fields and Regions in the Business Rules pane to open the business rules editor..
2. Click next to Collection Rules to open the Create Business Rule dialog box.
   
   

   
   Description of the illustration metadata-ext-collectionrule-create.png

   
   

   Rather than creating a rule from scratch, you can duplicate an existing rule and use it as the basis for a new rule, or create a rule from a business rule template. To duplicate a rule, right-click the rule in the list, and then click Duplicate.

   Note:

   When duplicating rules defined in extension dependencies (the rules listed under Built-in Rules):

   • You cannot duplicate a rule if it uses advanced expressions, for example, in the rule's condition or to override a field's value.
   • You cannot duplicate a rule if it uses any global functions that cannot be referenced in the extension. If the global functions are referenceable, when the rule is duplicated they are automatically imported, and the references to the function are updated in the rule.
   • When duplicating nested rules, you can only duplicate the top-level rule. When you duplicate the rule, the child rules are also duplicated.

   If there are any business rule templates defined in the app, you can select one using the Template dropdown list in the Create Business Rule dialog box:

   
   

   
   Description of the illustration metadata-visapp-brtemplate.png

   
   
3. Select the Rule Type in the dialog box.
   Select Regular to create a standard business rule. The other rule types (If/else and Switch) are special types of nested rules. For more about these nested rules, see Add an If/Else Rule and Add a Switch Rule.
4. Enter a label, id, and description for the rule.
   The id is generated automatically based on the label you enter, but you can modify the id if you wish. The description field is not required, but it can be helpful when you later try to understand what a rule is doing, especially when there are many rules.
5. Click Create

   Your new rule is added to the top of the list of extension rules under Collection Rules.

6. Click Edit, and then create a condition for the rule.
   See Set Conditions for a Rule.
7. In the Fields area, locate the field corresponding to the column you want to configure.

   In a table, each field corresponds to a table column. This means that if a dynamic table is configured to display four fields, the table will have four columns.

8. Click the dash—or an existing value—for the field's Hidden property, and select a new value for the property in the dropdown list.

   In a collection rule, the only property you can override is the Hidden property:

   
   

   
   Description of the illustration metadata-collectionrule-property.png

   
   

   The Hidden property has three options:

   • Hidden by Default hides the table column when the page is rendered. A user can still use the table's popup menu to hide and show the column.
   • Visible by Default displays the table column when the page is rendered. A user can still use the table's popup menu to hide and show the column.
   • Always Hidden hides the table column. When this option is selected, a user cannot use the table's popup menu to display the column.

   In a collection rule, you can set the Hidden property for a field even if it's not included in a table. The Hidden property in a collection rule is only applied to table columns. (The property does not affect fields in forms.)

   Depending on how the app was configured, you might have options for filtering the list of fields displayed in the editor. The Show only fields used by layouts option filters out the fields not included in layouts. If you don't select this, the list contains all the object's fields. The Show only fields with overridden properties option limits the list of fields to those that have been modified by a rule.

To delete a rule, right-click the rule in the list to open the popup menu, and then click Delete.

Rules are evaluated in order, from bottom to top, so all extension rules are evaluated after the built-in rules. As you create more rules, make sure you position each one in the order you want them evaluated, using the grab handles (six dots) beside the rules to drag-and-drop them to new positions. You can find out more about how rules are evaluated in Understand What Will Be Shown at Runtime.

If you decide you don’t want to include a rule in the evaluation order, select the rule, then use the Active toggle switch in the upper right corner to deactivate it. (You can also right-click a rule and deactivate and activate it in the popup menu.) This enables you to still keep the rule so you can re-activate it later. You can tell at a glance if a rule is inactive because a little badge appears next to it, like this:

Description of the illustration inactiverule.png

Inactive rules are not included in the rule evaluation process.

Note:

You can deactivate all the extension rules at once by clicking the three dots next to the Extension Rules heading, then clicking Deactivate All. This can be useful when debugging a page, allowing you to see the page with only the built-in rules applied. Use Activate All to reinstate all the rules at once, or use the Active toggle to selectively activate them as you work through your debugging process.