dev/financial#120 - Fix CiviCRM base URL on Joomla frontend

[eileenmcnaughton]

Overview

This fixes loading of several JS+CSS assets for front-end pages (such as the contribution page) on CiviCRM-Joomla.

See also: https://lab.civicrm.org/dev/financial/issues/120

(This PR is a revision/alternative to #16760 for which Seamus did the primary analysis. This variant iterates on code style.)

Background

• Joomla splits CiviCRM between two "components" -- a backend administrator component and frontend/user component.
• Each component has a different civicrm.settings.php and a different CIVICRM_UF_BASEURL.
• CiviCRM's JS and CSS assets are physically stored under administrator/components/com_civicrm/. Regardless of whether the web-page is a frontend or backend screen, it should load JS/CSS assets from the administrator side.
• In Civi v5.23.alpha (1143a78), the URL construction for certain folders (esp civicrm/bower_components and civicrm/packages) changed subtly.

Before

CiviCRM JS and CSS assets do not load on Joomla front end forms.

The asset URLs incorrectly point to (nonexistent) JS/CSS files in the user component.

The URL variable [civicrm.root] (and therefore [civicrm.packages], [civicrm.bower]) does not truly point to the public URL of CiviCRM assets.

After

CiviCRM JS and CSS assets do load on front end forms.

The asset URLs correctly point to (existent) JS/CSS files in the administrator component.

The URL variable [civicrm.root] (and therefore [civicrm.packages], [civicrm.bower]) does point to the public URL of CiviCRM assets.

(Original description from seamus. Revised by totten.)

[civibot]

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[seamuslee001]

This looks good to me I think this will work

[eileenmcnaughton]

@seamuslee001 shall we merge through to 5.23 ready for @totten to drop when he is around?

[totten]

This is some really good analysis/fixing @seamuslee001.

I do think this variant of the patch is a bit nicer (r-code) as it includes a bit of cleanup on some old mess.

[totten]

• Note that there was more discussion/review on Mattermost (product-maintenance).
• r-run: I've run on Joomla 3.9 with/without the patch and confirmed that (a) before the patch, various URLs were malformed on the contribution page (b) after the patch, they worked.
• r-explain: The explanation was better on the original PR. I'll copy some bits + revise here then merge.