Restrict the value range for references

For object class properties of the type Reference or Reference Array the Type Info attribute of the object class property in the class model defines which object classes can be the reference target.

In Alfabet Expand, you can view the setting in the Meta-Model tab. Expand Classes > the relevant object class > Properties and click the relevant object class property. You can see the Type Info attribute setting in the attribute window. The Type Info attribute is not editable in the standard object class model.

You can further restrict the specified reference targets with one of the following methods:

Limit reference targets to objects of a specific object class or object class stereotype. If object class stereotypes are defined for a target object class you can define that the reference should only target a subset of the available object class stereotypes. If the reference can target multiple object classes, you can exclude some of these object classes as possible target for the reference.
Limit reference targets to objects returned by a query. If you want to restrict the objects a user can select as reference target to a range of objects for which specific conditions apply, you can define a query returning the objects a user shall select from when setting the reference. This setting is only available for protected and custom object class properties.

If you define both restrictions for an object class property, the user can only select objects to which both rules apply.

If you define a range restriction for an object class property already in use, already available settings not matching the restriction will persist in the database until a user manually changes them to an allowed value.

Limit reference target object class or stereotype

If the Back Reference attribute of the object class property establishing a reference shows the name of an attribute of the target object class, the target object class also stores the reference in the defined object class property. For example, if an application is assigned to an application group, this is stored both in the object class property Applications of the application group and the object class property ApplicationGroups of the application. If you restrict the range of the reference, you need to configure the target object class as well. For example, if you limit the Applications object class property of the object class ApplicationGroup to applications of one of five application stereotypes only, you must hide the object class property ApplicationGroup from the other four object class stereotypes of the object class Application.

You have defined class settings for the object class. Whether your settings are used as default or for users logged in with defined user profiles only depends on the definition of the class settings for which you are configuring the object class properties

Go to the Presentation tab.
In the explorer, expand the nodes Class Settings > the object class (stereotype) you would like to edit > the class settings you would like to edit.
Right-click the Properties node and select Modify Property Behavior.
The new property modification will be added as the last child node of the Properties node with a random property assignment. Click the node and select the relevant object class property in the Property Name attribute.
Each object class property can only be added once to the Properties node. If you do not find the object class property in the drop-down list, there will be already a modification for this property. Change the existing property modification node.
Open the editor of the Value Range Definition > Limit to Classes or Stereotypes attribute, select the checkmark of all object classes or object class stereotypes that you want to allow as reference target and click OK.
Open an editor for an attribute
Click in the attribute value field. A button for opening the editor appears on the right of the field.
Optionally, change the caption, hint and availability on the user interface for the object class property to match your reference target selection.

Limit references to objects returned by a query

If the Back Reference attribute of the object class property establishing a reference shows the name of an attribute of the target object class, the target object class also stores the reference in the defined object class property. For example, if an application is assigned to an application group, this is stored both in the object class property Applications of the application group and the object class property ApplicationGroups of the application. If you restrict the range of the reference, you need to configure the target object class as well. For example, if you limit the Applications object class property of the ApplicationGroup object class to a defined range of applications only, you should hide the object class property ApplicationGroup for the Application object class.

The restrictions will only be applied to data workbenches, property groups in data workbenches, and guided data entry views. If you have migrated from an Alfabet 10.15.x release, you need to additionally configure the restriction in your editors and wizards with the methods valid for editors and wizards.

Go to the Presentation tab.
In the explorer, expand the nodes Class Settings > the object class (stereotype) you would like to edit > the class settings you would like to edit.
Right-click the Properties node and select Modify Property Behavior.
The new property modification will be added as the last child node of the Properties node with a random property assignment. Click the node and select the relevant object class property in the Property Name attribute.
Each object class property can only be added once to the Properties node. If you do not find the object class property in the drop-down list, there will be already a modification for this property. Change the existing property modification node.

Open the editor of the Value Range Definition > Range As SQL Query attribute or the Value Range Definition > Range As Alfabet Query and define either a native SQL query or Alfabet query according to the following rules:

The query must return objects of a target object class defined in the Type Info attribute of the object class property:
- If you define an Alfabet query, the FIND class must be the target object class.
- If you define a native SQL query, the first column defined in the SELECT statement must return the values of the REFSTR object class property of the target object class.

You can use Alfabet query parameters except the BASE parameter and parameters related to specific context, like wizard or workflow related parameters.

Alfabet query parameters

You can use Alfabet query parameters in both native SQL queries and Alfabet queries to refer to the current context in the Alfabet user interface. For example, to refer to the object the user is currently working with, the user executing the report, or the current workflow being executed in WHERE clauses. During execution of the Alfabet query, the Alfabet parameter is substituted with the current return value. If no value is returned, the Alfabet query is executed without the WHERE statement.

Write Alfabet parameters as:

@ParameterName

For example:

WHERE APPLICATIONGROUP.BELONGSTO CONTAINS @BASE

finds all application groups subordinate to the application group the user is currently working with on execution of a native SQL query.

The following Alfabet parameters can be used for Alfabet queries and native SQL queries:

Parameter Name	Description
BASE	Returns the value of the REFSTR property of the current object.
CURRENT_PROFILE	Returns the value of the REFSTR property of the current user profile.
CURRENT_USER	Returns the value of the REFSTR property of the current user.
CURRENT_MANDATE	Returns the current mandate of the user. The Alfabet parameter can be used for example to limit search results to objects that are assigned to the mandate the user is currently logged in with, for example: ALFABET_QUERY_500 FIND ICTObject WHERE ICTObject.MANDATEMASK CONTAINS @CURRENT_MANDATE NOTE: The parameter CURRENT_MANDATE (and the whole statement it is used in) is ignored if the user has no mandate assigned or is working as mandate master.
CURRENT_CULTURE	Returns the Microsoft® Windows® Locale identifier (LCID) of the current culture of the Alfabet user interface. Please note that the culture that is selected as default culture is always returned as 127, which means default, independent from the LCID of the culture.
TODAY	Returns the current date.
ALFA_SERVER_URL	Returns the value of the attribute Web Server of the server alias configuration of the Alfabet component processing the query. The attribute Web Server is editable in the Overview tab of the server alias configuration editor.
BASE<number>	For queries defined in the context of layered diagrams and grid reports only! If the report is configured to allow cascading queries, and more than one level of related objects us defined, BASE0 returns the value of the REFSTR property of the parent object in the directly superordinate level of the diagram. BASE1 returns the ancestor object in the level superordinate to the parent object level etc.
WIZARDBASE	For queries defined in the context of wizard configuration only! Return the value of the REFSTR property of the base object of the wizard. The base object of the wizard can be different from the base object of a wizard step. This parameter allows to refer to the base object of the wizard for example in pre-conditions of steps that have a different base object than the overall wizard.
WORKFLOW	For queries defined in the context of workflow configuration only! Returns the value of the REFSTR property of the workflow. Each workflow corresponds to an object Workflow in the Alfabet database. The parameter is useful when defining queries that refer to properties of the class Workflow, like for example the workflow owner or the workflow initiator. .
WORKFLOWBASE	For queries defined in the context of workflow configuration only! Returns the value of the REFSTR property of the base object of the workflow. The base object of the workflow can be different from the base object of a workflow step. This parameter allows to refer to the base object of the workflow for example in pre-conditions of steps that have a different base object than the overall workflow.
LAST_EXECUTION	For queries defined in the context of monitors only. Returns the date of the last execution of the monitor.

The information displayed in the selector on the user interface is not taken over from the query. The Image Properties defined in the class settings are used and sorting is done in alphanumeric order.
If an enumeration is assigned to the object class property in the Enumeration attribute, you can only further restrict the range to a subset of the strings defined in the enumeration. If the query defines values outside the enumeration scope, these values are ignored. The order of strings in the query supersedes the order of strings in the enumeration.

Optionally, change the caption, hint and availability on the user interface for the object class property to match your reference target selection.

Open an editor for an attribute

Open an editor for an attribute

Alfabet query parameters