Operating Feature Removal rules

Prerequisite:

Before configuring a Feature Removal rule, you must check that the schematic feature class required for the rule execution already exists in the schematic dataset and is associated with the schematic diagram template on which the rule is going to be specified.

The Feature Removal rule allows you to remove all or particular schematic features implemented by a given schematic feature class from the schematic diagrams. The rule doesn't preserve the network topology during its execution. For example, if schematic nodes are configured for removal, the rule will not try to reconnect their connected links to any target node like the reduction rules do; any node removal will cause its connected links to also be removed from the resulting diagram.

You can choose to remove either all the schematic features implemented by the specified schematic feature class or only some of them that have been filtered out according to the following:

• A SQL filter that works on the real feature class/object table associated with that schematic feature class
• Any particular schematic attribute on the schematic features that connect to the schematic features candidate for removal, or any particular field on the real feature classes/object tables associated with the schematic feature classes that implement the schematic features that connect to the schematic features candidate for removal
• Custom extended criteria that have been specifically developed to determine which schematic features are going to be removed

The steps below focus on the configuration of the Feature Removal Rule Properties tab that is displayed when clicking the Rule Properties button on the Rules tab toolbar while such a Feature Removal rule has already been added to that tab. To learn about how to add any new rule on the Rules tab and display the Rule Properties dialog box, read the Specifying a schematic rule on a schematic diagram template topic.

For a Feature Removal rule that has just been added on the Rules tab, clicking the Rule Properties button on the Rules tab toolbar opens the Rule Properties dialog box as follows:

1. Type a description for the rule in the Description text box.

   This description string will be displayed on the Rules tab for the related rule item and will also be displayed during the schematic diagram's generation and update to inform users that the rule is being executed.

2. Choose the name of the schematic feature class to be removed from the Select the schematic feature class to remove drop-down list.

   All schematic feature classes that are associated with the schematic diagram template are available from this list.

   At this step of the rule configuration, all the schematic features implemented by that selected schematic feature class are configured for removal.

3. Check Remove orphan nodes caused by a link being removed if you want the nodes that will become orphans after link removals to also be automatically removed from the resulting diagram.
4. If you want to designate a SQL filter on the specified schematic feature class so that only certain nodes are removed, do the following,
   1. Click the Edit button at the right of the SQL Filter on associated feature/object class area.

      The SQL Query dialog box opens.

   2. Build the SQL expression you want.

      The filtering operates on the fields stored on the feature class or object class that is associated with the specified schematic feature class.

   3. Click OK.

      The SQL Query dialog box closes, and the SQL filter you have just specified automatically appears in the SQL Filter on associated feature/object class area.

   The specified SQL filter will then be used to determine the subset of the schematic features candidate for removal. Those that don't verify the SQL filter will not be removed during the rule execution.

5. If you want the schematic features candidate for removal to depend on a schematic attribute on the schematic features connecting them or on a field stored on the GIS feature classes associated with the schematic feature classes that implement the schematic features connecting them, do the following:
   1. Check the Connected features attribute check box.
   2. Type the name of the schematic attribute or field that will be used.
      • When the selected schematic feature class to remove implements nodes, the rule works on the links connected to the nodes candidate for removal.

        For each schematic link that connects to a node candidate for removal, the rule first searches for a schematic attribute with this name on the schematic link. If no schematic attribute with this name is detected, the rule searches for a field with the same name on the GIS feature associated with the schematic link.

      • When the selected schematic feature class to remove implements links, the rule works on the origin and end nodes of the link candidate for removal.

        For each schematic node that connects to a link candidate for removal, the rule first searches for a schematic attribute with this name on the schematic node. If no schematic attribute with this name is detected, the rule searches for a field with the same name on the GIS feature associated with the schematic node.

   3. Choose Not equal or Equal if this attribute/field value must be equal or not for all the connected schematic features so the schematic feature candidate for removal is finally removed.
      • When the selected schematic feature class to remove implements nodes, choosing Not equal causes the schematic node candidate for removal to be thus removed only if the specified schematic attribute/field doesn't exist for some connected links, or if it exists for all the connected links but with different field values. Choosing Equal causes the schematic node candidate for removal to be removed only if the specified schematic attribute/field exists with the same value for all its connected links.
      • When the selected schematic feature class to remove implements links, choosing Not equal causes the schematic link candidate for removal to be removed only if the specified schematic attribute/field doesn't exist for one of the origin or extremity nodes, or if it exists for both origin and extremity nodes but with different field values. Choosing Equal causes the schematic link candidate for removal to be removed only if the specified schematic attribute/field exists with the same value for both its origin and extremity nodes.
6. A specific extended criteria can also be specified to filter out the nodes candidate for removal. To use such a criteria, you must do the following:
   1. Check the Use extended criteria check box.
   2. Choose the desired extended criteria from the drop-down list.

   A custom extended criteria for the Feature Removal rule is a component that implements the esriSchematic.ISchematicFeatureRemovalExtended interface.

   Note:

   The Use extended criteria drop-down list and the Use extended criteria check box on the Feature Removal Rule Properties page are unavailable when no custom feature removal extended criteria is registered on the computer in the ESRI Schematic Rules Extended Criteria category.

   The extended criteria component works on the schematic features candidate for removal according to all the other specified removal options. It determines whether or not each node will be removed after the rule execution.

7. Click OK to close the Rule Properties dialog box.

• Feature Removal rule sample results