[JENKINS-73911] Un-inline JavaScript in trend-chart.jelly

[yaroslavafenkin]

https://issues.jenkins.io/browse/JENKINS-73911

Testing done

Tested with warnings-ng and forensics-api being API consumers. Below are the scenarios I've had in mind.

https://www.loom.com/share/2b4acc3c16b34477b337f829077e550b?sid=9a6559cc-a3e9-4edd-a0c4-04957e5df077

https://www.loom.com/share/5a48e07ae13740fdaf00837d2154ec0d?sid=9a32b2c2-f848-4c55-9293-321dfde05c8b

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 51.42%. Comparing base (52e861b) to head (d542ca5).
Report is 83 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##               main     #357   +/-   ##
=========================================
  Coverage     51.42%   51.42%           
  Complexity       17       17           
=========================================
  Files             7        7           
  Lines           105      105           
  Branches          3        3           
=========================================
  Hits             54       54           
  Misses           51       51           

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[uhafner]

I deployed it locally and all existing trend charts still work.

[uhafner]

Can you explain what the window[...] does? It works but I do not understand the semantics.

[yaroslavafenkin]

It's a way of accessing a global variable.
The variable is declared by the internals of <st:bind value="${it}" var="trendProxy${generatedId}" /> and it's in the global scope. I do not know upfront what the name of the variable will be because generatedId is generated in runtime. I'm passing the generatedId as a data attribute to the script so that I can access the object the name of which I can only know in runtime.

I could alternatively pass the name of the variable to the script instead of generatedId as I did in jenkinsci/warnings-ng-plugin#1862. Though the window[...] syntax still stays.

If the name was static we would simply access the variable by its name (like e.g. echartsJenkinsApi is accessed on this exact line).

Let me know if it's more clear now.

[uhafner]

I see thanks! So this trick is to get the actual value while using the key trendProxy${generatedId}.