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Data Transforms

Purpose

A data transform defines how to convert data that is in one format and class (the source) into data of another format and class (the target). The supported formats are clipboard and JSON. Using a data transform instead of an activity to set property values speeds up development and makes application maintenance easier.

Data transforms are useful:

When using data pages to manage application data (see the Where referenced section 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.

You can create a data transform for either a clipboard or JSON model format. You select the type of data transform in the Additional configuration options section on the Create Data Transform form. The options are different depending on which model format you choose.

For the JSON model format, you can choose whether to automatically map all data in the JSON string, or you can map individual properties. Mapping individual properties is useful when you have a large JSON string and you only care about a couple of properties, when you want to change the JSON structure, and when the fields in the JSON have different names than the clipboard properties to which you are mapping. In addition, you can select classes to exclude.

Where referenced

The following data transforms that are used for data management use data pages:

Optional data mapping on the property form – On the Edit Property form, the Optional Data Mapping field appears when you select Copy data from a data page. Use this data transform to copy a subset of the data from the data page to the property. If you do not specify a data transform, the system copies all of 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 Pega Platform data to the fields that the connector needs to communicate with the data service. Select the data transform to use in the Request Data Transform field on the Data Page rule form on the Definition tab, in the Data sources section.
Response data transform – Response data transforms normalize data provided by the data sources into the common application data model. 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). Select the data transform to use in the Response Data Transform field on the Data Page rule form on the Definition tab, in the Data sources section. For more information, see the PDN article Data virtualization in PRPC.

Other parts of Pega Platform 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 by using the Flow form, 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:

Action restrictions

The following property types have limited support in data transforms and have no support in JSON data format transforms:

Page groups
Value Lists
Value Groups

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.