Back-Referencing
When using the interactive CLI, a common scenario will be using an id from a previous result as the input to the next command. Back-referencing provides a shortcut for referencing a result from the previous command via a positional reference.
#> registry list-buckets help
Lists the buckets that the current user has access to.
PRODUCES BACK-REFERENCES
A common scenario for utilizing back-references would be the following:
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User starts by exploring the available buckets in a registry instance
#> registry list-buckets # Name Id Description - ------------ ------------------------------------ ----------- 1 My Bucket 3c7b7467-0012-4d8f-a918-6aa42b6b9d39 (empty) 2 Other Bucket 175fb557-43a2-4abb-871f-81a354f47bc2 (empty) -
User then views the flows in one of the buckets using a back-reference to the bucket id from the previous result in position 1
#> registry list-flows -b &1 Using a positional back-reference for 'My Bucket' # Name Id Description - ------- ------------------------------------ ---------------- 1 My Flow 06acb207-d2f1-447f-85ed-9b8672fe6d30 This is my flow. -
User then views the version of the flow using a back-reference to the flow id from the previous result in position 1
#> registry list-flow-versions -f &1 Using a positional back-reference for 'My Flow' Ver Date Author Message --- -------------------------- ------------------------ ------------------------------------- 1 Tue, Jan 23 2018 09:48 EST anonymous This is the first version of my flow. -
User deploys version 1 of the flow using back-references to the bucket and flow id from step 2
#> nifi pg-import -b &1 -f &1 -fv 1 Using a positional back-reference for 'My Bucket' Using a positional back-reference for 'My Flow' 9bd157d4-0161-1000-b946-c1f9b1832efd
The reason step 4 was able to reference the results from step 2, is because the list-flow-versions command in step 3 does not produce back-references, so the results from step 2 are still available.
