Declare Index form - Completing the Indexes tab
Use this tab to convey how and when the system constructs an index in a database. The system forms an index instance from the Purpose key part of this rule and the handle of the base instance.
| Field | Description |
|---|---|
| Source page context |
Identify a page that contains the properties used in completing the index
data. Typically, this is an embedded page.
Alternatively, enter a pattern that
is a
to cause the system to create an index for every embedded page in a top-level page that fits this pattern. |
| Source page context class |
Identify the class of the page or pattern entered in the
Source Page Context
field, typically a class derived from the
Embed-
base class. In most cases, set this value to match the
PageClass
field on the
General
tab of the property.
You cannot use the keywords
|
| Index class to write | Identify a concrete class derived from the Index- base class that is to contain the index instances maintained by this rule. |
| Properties for indexing and mapping |
Enter in this array the sources of property values to be saved in this index. The order of sources is significant; this determines the sort order of index instances.
To reorder the rows of this array, hold the mouse pointer over a number. Click and drag to another row. To duplicate or move a row, hold the mouse pointer over a number. Or, right-click to access a context menu with Cut, Copy, and Insert options. |
| Source class property |
Enter a property reference to a
Single Value
or
Value List
mode property including a preceding period character. The property may have any Type, including
DateTime,
Decimal, or
Integer. This property need not be a distinct exposed column in the database table that contains the source class.
It is possible to use page name keywords "top" and "parent" in property references ("parent.property" would refer to a property on the page one level up from the class identified in the Source Class Context field; "top.property" would refer to a property on the primary or top-level page of the Applies To class); however, these references are not reliable. Change tracking only works with properties that are defined within the page context path. references to "top", "parent", or another named page are not within that path. If you have an instance, and you change a property which is referred to by a "parent" or "top" reference, you cannot be sure that the indexes for that instance will be updated. Avoid using "top" or "parent" references unless the properties they refer to are constant throughout the lifetime of an instance. |
| Mapping |
Select
Equals.
|
| Index class property | Identify in each row of this array the destination property, available in the class you entered in the Index Class To Write field, that is to hold the value of the source property. |
| Indexing conditions | |
| When |
Optional. Enter the second key part of a when condition rule to further qualify which indexes are created by this rule, or an expression resulting in a Boolean value.The system uses the
Applies To
key part of this Declare Index rule as the
Applies To
key part of the when condition.
The system evaluates this rule or expression each time an instance of the Applies To class is saved by any requestor. Both outcomes — true and false — may create or remove indexes:
|
| Index even when a source property is blank |
Select to create index objects even if one or more of the
Source Class Properties
listed has no value.
Clear to create index objects only when all the source properties have a non-blank value. |