Element ''DataRequest''

Element ''zpro > DataRequest''

(Since version 5.0)

DataRequest elements are used to invoke the data sources explicitly by means of causing to create <dataRequest> definitions in the page configuration.

As a matter of fact <dataRequest> definitions are also created by Application Studio when related definitions made in "Page Data Requests" properties of pages or when the name of the data sources are mentioned anywhere in the page.

Differently this element ("DataRequest") gives the possibility to call the data sources with parameters to acquire different results.

DataRequest

Properties

Data Source Name (Accepts MScript)

The name of the data source that will populate the required data.

Nr. of Extra Items At The Top (Accepts MScript) (Since version 5.2)

The number of the items (records) to be inserted at the top of the populated items.

Nr. of Extra Items At The Bottom (Accepts MScript) (Since version 5.2)

The number of the items (records) to be appended at the bottom of the populated items.

Add One Item If Empty (Accepts MScript) (Since version 5.2)

If true specified, an empty item (record) is added in case of no item is populated by the data source.

Sequence

Unless otherwise specified the data requests are processed in the runtime in the order of their usage in the page. The one used at the top most, is processed in the first place, and the one used at the bottom most is at the last place. In case of a data source depends on another one, this order can be important.

The processing order of the data requests can be specified explicitly by using this property. If, for argument, we want that a particular data request is processed at the last place we can specify 99 in this property.

Data Source Parameters (Accepts MScript)

As it is shown in the example below, the values for the parameter variables (prefixed with "c:") can be specified in XML format in this property.

select * from products where PCAT_ID = @vof(c:CAT_ID)

Other than <param> definitions, this property also allows <node> definitions which you usually specify in "Page Data Requests" properties of the pages.

Example: