Document minimal gettext version for ES6 template strings support

[Cédric Eberhardt]

Hello,

Before I start, it's different than the #29175 issue.

The template strings are parsed, but partially.
For instance, in this code, "Home" is never discovered.

function create_fragment$4(ctx) {
	return {
		c() {
			div2.textContent = `${window.gettext("Customized Champagne")}`;
			attr(a0, "aria-label", a0_aria_label_value = window.gettext("Home"));

If I remove the textContent line, then "Home" is found.

I've also found other examples where when I remove a previous template string line, the next gettext (not necessarily within a template string) is discovered again.

Thanks.

[Simon Charette]

I wonder if it's because ​our current JS lexer gets confused by that string.

[Cédric Eberhardt]

The output from prepare_js_for_gettext is the same as the code above.

Does it means that it's a problem from xgettext? (found ​on makemessages.py)

[Simon Charette]

Based on c3437f734d03d93f798151f712064394652cabed which ​links to the gettext bug tracker I'm fairly confident this is a duplicate of #29175 .

From ​this comment.

So a template string inside any code block, {}, seems to cause xgettext to skip the rest of the file during parsing without warning or error.

That's exactly what you are experiencing here since removing the textContent line allows following parsing to take place.

​Looks like it was fixed in 2.0+ though so maybe we should re-purpose this ticket as a documentation adjustment? Could you try downloading the latest gettext and see if it helps anyhow?

From ​the changelog of 2.0 released May 2019

• JavaScript:

xgettext now parses template literals correctly.

[Cédric Eberhardt]

Thanks for the info. You're right. I tried with xgettext 0.20.1 (from Homebrew on macOS) and, as expected (and documented :P ), it doesn't work properly. Apparently there is a bug fix for xgettext from last summer, I'll try it.

[Claude Paroz]

​PR

[Mariusz Felisiak <felisiak.mariusz@…>]

In 2f53d324:

Fixed #31341 -- Doc'd minimal gettext version with ES6 template strings support.

[Mariusz Felisiak <felisiak.mariusz@…>]

In e3069f66:

[3.0.x] Fixed #31341 -- Doc'd minimal gettext version with ES6 template strings support.

Backport of 2f53d324debee680658aed7f22f1aaf81385b1f2 from master