***Note from Migration:***
Original Title was: Create a warning/error within/at transformers to indicate deleted parameter references (similar to missing attribute references)
Whenever using attribute values in a transformer, FME provides users a clear error indication when an attribute is being referenced that doesn't exist anymore.
However, when using a parameter value in a transformer, FME doesn't provide an error indication when a parameter is being referenced that doesn't exist anymore. Instead, when a parameter is being deleted that was still being referenced in the workspace, the parameter reference is replaced with the previously known (default) value of that parameter (at all of the locations where the parameter was being referenced).
I believe it would be a great enhancement when the functionality for indicating missing/deleted attribute references, could also be implemented for missing/deleted parameter references.
----- some considerations -----
I believe that the current behaviour of replacing an active parameter reference with the parameter value, on the moment this parameter is deleted, is a bit tricky. This is because in case a user deletes a parameter while overlooking that it still has an active parameter reference, he/she might still expect certain settings/values to be handled dynamically, while in fact settings/values now rely on the fixed previously held value of the parameter.
I know that one can check at which locations a parameter is being referenced from within the Navigator window (a functionality I'm really happy with), and may also use this in combination with the workspace search functionality from the navigator window to alter/correct all parameter references before removing an existing parameter. However, when one is in the developing/testing fase of a workspace/custom transformer, changes are made quite quickly and forgetting about a specific parameter reference is an easy mistake to make.
----- example 1, FeatureReader -----
A1) (See zipfile) Correct Dataset configuration using attribute 'fileurl'
A2) Current result when attribute 'fileurl' no longer exists (Incorrect Dataset configuration)
(Note that within the AttributeCreator the attribute name was (deliberately) changed to 'fileurl_2')
Note that the cogwheel of the FeatureReader turns red, and that the 'Dataset Field' turns red, while still showing the old invalid attribute reference, (indicating it no longer exists).
B1) (See zipfile) Correct Dataset configuration using parameter 'fileurl'
B2) (See zipfile) Current result when parameter 'fileurl' is deleted (Incorrect Dataset configuration)
(Note that by deleting the parameter 'fileurl' the reference is replaced with the previously held value of the parameter 'fileurl', which in this case was not set, resulting in an empty dataset field).
Note that the cogwheel of the Featurereader does not turn red in this case, while the dataset field does turn red in this case.
B3) Desired result when parameter 'fileurl' is deleted (Incorrect Dataset configuration)
Note that I changed the image to match the current 'attribute error formatting' as shown by A2). In particular I would like to see the cogwheel of the FeatureReader to also turn red in this analogous parameter case. Furthermore I would like to see that the 'Dataset Field' is red (which it currently already is), while still showing the old invalid parameter reference, (indicating it no longer exists, which is currently not the case).
----- example 2, AttributeCreator -----
C1) (See zipfile) Correct value configuration (c.q. evaluation) for attribute 'numberAttribute_times_2'
C2) Current result when attribute 'numberAttribute' no longer exists (i.e. invalid configuration (c.q. evaluation) for attribute 'numberAttribute_times_2')
(Note that within at AttributeCreator_2, the attribute name was (deliberately) changed to 'numberAttribute_2')
Note that the cogwheel of the AttributeCreator turns red, and that the 'Attribute Value Field' turns red, while still showing the old invalid attribute reference (c.q. expression). Also note that within the Arithmetic editor the name of the no longer existing attribute is colored red (indicating it no longer exists).
D1) (See zipfile) Correct value configuration (c.q. evaluation) for attribute 'numberParameter_times_2'
D2) (See zipfile) Current result when parameter 'numberParameter' no longer exists (i.e. invalid configuration (c.q. evaluation) for attribute 'numberParameter_times_2')
(Note that by deleting the parameter 'numberParameter' the reference is replaced with the previously held value of the parameter 'numberParameter', which in this case was not set, resulting in an invalid arithmatic expression for the value of the attribute 'numberParameter_times_2').
Note that the cogwheel of the AttributeCreator does not turn red in this case, nor that that the 'Attribute Value Field' turns red (the invalid arithmic expression will only show when running the workspace, warning the user that due to the invalid expression the value will be set to 'Null'). At last, also in the Arithmetic editor, there is no indication that the expression is invalid.
D3) Desired result when parameter 'numberParameter' no longer exists (i.e. invalid configuration (c.q. evaluation) for attribute 'numberParameter_times_2')
Note that I changed the image to match the current 'attribute error formatting' as shown by C2). In particular I would like to see the cogwheel of the AttributeCreator to also turn red in this analogous parameter case. Furthermore I would like to see that the 'Attribute Value Field' turns red, while still showing the old invalid parameter reference (c.q. expression). At last it would be nice that the invalid parameter reference would also be shown in the Arithmetic editor by coloring the name of the no longer existing parameter red.
