Change Data Capture Developer Guide

Change Data Capture
Keep Your External Data Current with Change Data Capture
Change Event Message Structure
Merged Change Events
Other Types of Change Events: Gap and Overflow Events
Subscribe to Change Events
Monitor Change Event Publishing and Delivery Usage
Security Considerations
Change Event Considerations
Standard Object Notes
Change Events for Fields
Sending Data Differences for Fields of Updated Records
Data Differences in Event Fields
How to Reconstruct a Field from Its Diff Value
Considerations for Newline Characters and Computing the SHA-256 Hash
Change Events for Custom Field Type Conversions
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Note: This release is in preview. Features described here don’t become generally available until the latest general availability date that Salesforce announces for this release. Before then, and where features are noted as beta, pilot, or developer preview, we can’t guarantee general availability within any particular time frame or at all. Make your purchase decisions only on the basis of generally available products and features.

Considerations for Newline Characters and Computing the SHA-256 Hash

The content that Salesforce uses to generate the SHA-256 hash might have newline characters transformed by the browser. Many browsers transform newline characters to \r\n in record field values before records are stored in Salesforce. Also, Salesforce trims leading and trailing white spaces in field values.

Before you generate the SHA-256 hash value, ensure that the reconstructed content from the diff contains the same newline characters as the original content and that no new leading or trailing white spaces are added. For example, when you save the content in a file, the operating system can add a trailing white space character.

If you used the API to create or update field values, the newline characters supplied by the application are honored and stored in Salesforce without further transformations.

Windows systems represent the newline character as a carriage return and line-feed character sequence (\r\n). UNIX and UNIX-based systems, like macOS and Linux, represent the newline character as a line-feed character (\n).

Note