Change detection (diff/delta)
  • 19 Jul 2021
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Change detection (diff/delta)

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Article Summary

Change detection is a feature of that can be used to determine when specific values of robot execution results change. Change detection can also be seen as diffing or delta functionality.

Output values from the robot that you choose are compared from the current execution with the previous execution; in effect, providing a sliding window of changes.

Enable change detection

Contact us if you would like this feature enabled on your account.

  1. Search for change detection in Apps.
  2. Select Contact Dexi.

Screenshot 2021-03-25 at 11.05.57.png

Configure change detection

Once the app is enabled, the feature is enabled for a configuration of a robot by checking the Track changes? checkbox:

Screenshot 2020-02-06 at 13.33.01.png

The Key fields define the fields that are used to determine the uniqueness of a row (i.e., when the values of the key fields match across the previous and the current execution). The values from the Value fields are then compared:

  • If values are new, the row is marked as Created.
  • If values are unchanged, the row is marked as Existed.
  • If values have changed, the row is marked as Changed.
  • If values were deleted, the row is marked as Deleted.

A field cannot be selected as both a key and value field and currently, only non-file, non-object, and non-array/list fields (i.e., simple fields), are supported for both key and value fields.

Results with change detection

The change status is added to the results as a separate field, Change — called @change when results are exported or when using change detection from triggers.

Example showing only Changed rows:
Screenshot 2020-02-06 at 13.46.30.png

If any rows were deleted, they are shown on the Deleted results tab.

The Old value prefix controls the name of the old fields, i.e., the fields of the rows of the previous execution. In the example below, the prefix previous- has been entered:

Screenshot 2020-02-06 at 13.50.31.png

If left blank, the prefix old- is used.


This part of Dexi doesn't have auto-save. Remember to save when you are changing any part of the change detection configuration (or any other part of the robot configuration for that matter).

Change detection with triggers

The old value fields and the @change field are available from triggers and can be mapped just like the normal fields from the result rows:

Screenshot 2020-02-06 at 13.58.14.png

See also:

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