About Data Transforms

Purpose

Use a data transform to define how to take source data values — data that is in one format and class — and turn them into data of another format and class (the "destination" or "target").

In general, data transformation involves both mapping data from a source to a target, and performing any conversions or other transformations on that data that might be required to achieve the intended mapped results.

Some examples of situations in which to use a data transform are:

• When using data pages to manage application data (see under "Where referenced", below.
• In activities, when:
  • Copying a clipboard page to make a new page.
  • Mapping properties (and their values) on one page to another, existing page.
  • Mapping properties (and their values) on one page to a new page.
  • On a given clipboard page, defining one or more initial properties on that page and setting their values. A data transform can set many property values on a page in one processing step.

See the help for the Definition tab and the individual help topics that describe the specific data transforms actions for further details and examples. See also PDN article Introduction to Data Transform rules.

Even though an activity could be used to set many property values on a page, using a data transform speeds development, because the data transform form is easier to understand than the Activity form.

Where referenced

There are three main data transforms involved in data management using data pages:

• Optional data mapping on the property form: The field "Optional Data Mapping" appears when you select "Copy data from a data page" as the data access method on the property's General tab. Select an available data transform or create a new one: the data transform copies a subset of the data from the data page to the property. If you do not select a data transform, the system copies all the data from the data page to the property.
• Request data transform: When a data source for a data page is a connector (an integration with an external data service), the request data transform lets you map PRPC data to the fields the connector requires to communicate with the data service.
• Response data transform: A field for this data transform appears next to each data source on the Definition tab of a data page. A response data transform is required when the data source class is incompatible with the data page class (the recommended pattern to achieve true data virtualization). Response data transforms normalize data provided by the data sources into the common application data model. For more on this topic, see the PDN article Data virtualization in PRPC.

Other parts of PRPC that reference data transforms include:

• Several activity methods that operate on pages can use a data transform, such as the Apply-DataTransform, Apply-Model (deprecated), Page-New, Page-Copy, and Page-Change-Class methods.
• Starter flows — flows that create work items — can specify a data transform (on the flow's Process tab) for a Work- class to set initial properties for the work item.
• Optionally, the Action tab for a flow action can specify that the system apply a data transform before or after displaying the flow action user interface to the user.
• Optionally, for flows that have been edited using Process Modeler, data transforms can be specified on the Set Properties tab of the Connector Properties panel.
• In various user interface elements, which include the Client Event Editor's:
  • Refresh This Section action
  • Refresh When conditions
  • On-click control rule actions Refresh Section, Show Harness, and Open URL In Window

Data transform rules can be referenced by other data transforms.

Rule types that create clipboard pages (such as Connector rules, Service rules, and other rule types) can use data transforms.

Actions

Use these topics to learn about a specific data transform action:

Access

Use the Application Explorer to access data transforms that apply to the work types in your application. Use the Records Explorer to list all data transforms available to you.

Category

Data transform rules are part of the Data Model category. A data transform is an instance of the Rule-Obj-Model class.

	How to unit test a data transform Apply-DataTransform method
	Standard data transforms

Data Model category

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