ngVars cause duplicate thumbnail bitstream requests

[bram-atmire]

Describe the bug
On pages where thumbnails are requested, Angular sends 2 requests to retrieve the bitstream instead of one.

Cause & solution approach

This is likely caused by the use of ngVars here and here

One path to address this would be to replace the occurences with their values.

To Reproduce
Steps to reproduce the behavior:

1. Open up inspect element
2. Go to https://demo.dspace.org/search?spc.page=1&query=%22A%20Strength-Based%20Approach%20to%20Indigeneity,%20Equity,%20Diversity,%20and%20Inclusion%20Program%20Evaluation%20in%20Higher%20Education%22 this is a search that should return two items with thumbnails
3. Check how many "content" requests there are

Expected behavior
There should be 2 content requests, one per file

Observed behavior
There are 2 requests per file

Related work
Link to any related tickets or PRs here.

[bram-atmire]

This is affecting both 7.6.x maintenance, as well as DSpace 8

[alanorth]

Good catch, @bram-atmire! I see it on our DSpace 7.6.1 instance too, though in Firefox at least each of the second requests are cached and take 0ms.

[bram-atmire]

you're right Alan, I can also see that in Chrome, if you have "Disable Cache" DISABLED (so if caching is ON) the duplicate requests are not visible.

Nevertheless, we likely still better clean up the use of ngVars anyway.

[ybnd]

We'd like to claim this one