Data Sources

Data Sources are elements that data columns can be based on. An Attribute column based on the Database View (DBVW) Data Source displays the value of the attribute from the elements selected by the view definition. An attribute column based on a Source Element (SRCELE) Data Source displays the value of the attribute associated with the element defined by that data source. Select the Data Sources tab to display the Data Sources for the Database View.

For the purposes of this user guide, an example Data Sources hierarchy is described:

• If a Database View is created that has the Element Types (ELEL) attribute set to UDA then the node at the top of the Data Sources tree represents the collection of UDA elements.

• If a SRCELEMENT node is created below this with its Expression set to OWNER, then the Source Element represents UGROs, the OWNER elements of the selected UDAs

• Since SRCELEMENTs are allowed to contain SRCELEMENTs navigation steps are incremental. Another node with its Expression set to OWNER represents UWRLs, the OWNERs of the OWNERs of the selected UDAs.

• The NAME attribute is present on UDAs, UGRO and UWRLs. Creating an Attribute column for the NAME attribute and selecting different Data Sources changes the element the NAME attribute is being displayed/edited on.

The user can create a new Data Source, delete, navigate to, cut, copy or paste a Data Source from the right-click menu.

Properties

The Properties part of the Data Sources tab displays the significant properties of the selected Data Source. If a DBVW is selected then only its description can be modified on the Data Sources tab. The Expression field must be filled out with a valid expression for SRCELE Data Sources to define the element navigation.

Allow row creation

To create new rows for the Database View or to enable the creation of the Data Source element in the event that it doesn't exist and a column value requires setting.

Note:
Dependent upon which element is selected as the Current Element CE determines if new rows or Data Sources element can be created.

Click to select the Allow element creation to enable the Creation Rules part of the Data Sources tab. The rules defined in the Creation Rules part of Data Sources tab are used for the element creation. If insufficient information is defined for the element creation then a prompt is displayed stating, this can include information such as OWNER and TYPE.

Allow row deletion

Deletes rows or data source elements from the Database View. Dependent upon which element is selected as the CE determines if rows or Data Sources element can be deleted.

Creation Rules

The creation rules define the information to create an element when requested and set up the initial state of the element created by setting attribute values and assigning status. The user must populate the Creation Rules part of the Data Sources tab to make sure additional information is not required during the element creation.

Auto assign or create owner - To create the new element in the first available owner or an ownership hierarchy if one isn't present, click to select the Auto assign or create owner check box.

Note:
As ownership is usually significant for an element, this must be used with caution.

Owner Expression - In the Owner Expression field, input the OWNER for the element being created, if left unset then the user is prompted for the OWNER. The expression can be that returns either the element such as ‘id /Equipment’ or a string expression that returns the name or identity of the element such as ‘/SITE_' + $!Param2.

Type Expression - In the Type Expression field, input a string expression returning the type of the element to create such as ';MyUdet'. If this isn't set then the user is prompted for the type of element to create.

Note:
A prompt is displayed t if the type can be derived.

Additional rules can be used to request information from the user (Parameters), set attribute values at the time of creation and assign status to the newly created element.