dev/civicrm-setup#1 CRM_Core_I18n - Don't require immediate bootstrap

[totten]

Overview

For civicrm/civicrm-setup#1, the general goal is to allow installing the
database schema without needing to run GenCode.

The current draft is crashing because the SQL does translation using ts().
But if you try to use ts() in a pre-boot environment, it will attempt to
boot automatically so that it can read $config->customTranslateFunction.

This is a chicken-egg situation. We haven't yet reached the phase where the
installer can boot up Civi... because we don't have the SQL... but the SQL
can't be generated (translated) because Civi hasn't been booted.

The aim of this patch is to loosen the coupling between ts()
and CRM_Core_Config so that ts() can be used on its own.

Aside: You might ask how this works today -- basically, GenCode does a
database-less-boot, which placates ts(). However, the civicrm-setup
will eventually need to do full-boot, and AFAIK we don't have any
situations where one transitions from database-less-boot to full-boot; I
have a gut fear that such a transition would be its own slipper slope.

Before

• On first invocation, ts() calls CRM_Core_Config::singleton() to probe for customTranslateFunction.
• Thereafter, it uses a short test on a static variable to avoid extra lookups.

After

• During the first 1..n invocations (pre-boot), ts() calls getBootService() to see if we're ready. On the first successful result, it calls CRM_Core_Config::singleton() to probe for customTranslateFunction.
• Thereafter, it uses a short test on a static variable to avoid extra lookups.

Comments

For r-run testing, I've done a few things:

• Go to "Administer => Localization => Language". Change from en_US to fr_FR and observe UI displays the new language.
• Go to "Administer => Localization => Language". Enable multi-lingual (en_US and fr_FR) and enable CMS-language inheritance. In Drupal, setup user preferences. Observe that the active language in Civi tracks the user preference.
• Run bin/setup.sh -g. Spot-check sql/civicrm_data.fr_FR.mysql to ensure that it contains translated strings.
• In civicrm.settings.php, create a function swedishchef($string). Go to "Administer => Localization => Language" and use swedishchef as the translation function. Observe that translations use this.

function swedishchef($string) {
  return "Bork, $string, bork";
}

(Note: UI elements in the dashboard are cached and require an explicit refresh to reflect changes in the language settings. The nav-menu gets translated most of the time, but it never seems to use custom-translation-function. However, that's not a new regression -- the same problem occurs without this patch.)

[JoeMurray]

I have reviewed from perspective of performance and am satisfied it is no worse than current implementation for the vast majority of calls, and have no concerns in other cases of first page load and pre-installed calls.

[eileenmcnaughton]

I read through the code & could make sense of the changes. Relying on @JoeMurray testing. Merging