@Sybren A. Stüvel (sybren) would be nice to get green light (or not) on this one ;)

• Removed newline
• Replaced conditional block with conditional expression

In D15615#444202, @Damien Picard (pioverfour) wrote:

I’ll make the requested change to printf formatting, but one strong argument in favor of the format() method, is that if the placeholders are named or numbered, word order can be changed. This is sometimes needed to get grammatical sentences in localization.

That's a good point. I wouldn't mind switching to that (either directly after this patch or when it actually becomes necessary), but then I feel it should be consistently done throughout the add-on, and not just for these few strings.

I'd like to hear from @Bastien Montagne (mont29) on this: is pgettext_tip() the correct function for translating strings passed to operator.report({'LEVEL'}, message)? From the docs, it seems that pgettext_iface() would be a better choice here, but in other places I can see translated text for the report() function it's indeed using pgettext_tip().

As a confusing counter-example, bl_operators/wm.py seems to use pgettext_iface() for tooltips, and pgettext_tip() for reports.

That’s a fair question, and one that’s tripped me and basically everyone else a lot. I found from T76101#980282 about this comment by @Bastien Montagne (mont29) in rB23df1a774b5b:

Cheap tip: anything that is not "Camel Case" and/or that is more than a few words long should use TIP_ translation, not IFACE_ one.

This is not explicitly stated anywhere in the docs as far as I know, but that’s the current behaviour of report(). If you want to test that yourself, the following script prints the translated version of “Shader AOV” only if the Tooltips translation is enabled, and it uses report() in the operator.

import bpy

class SimpleOperator(bpy.types.Operator):
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"

    def execute(self, context):
        self.report({"INFO"},"Shader AOV")
        return {'FINISHED'}

def register():
    bpy.utils.register_class(SimpleOperator)

if __name__ == "__main__":
    register()
    bpy.ops.object.simple_operator()

By the way, I learned that Python’s printf-style formatting actually does provide a way to use named placeholders:

print('%(language)s has %(number)03d quote types.' %
      {'language': "Python", "number": 2})

I’ve never seen it used and think it looks a bit weird, but with it there is no need to switch to format() for i18n.

Re tip vs iface, main point has already been said, will update the official docs asap with detailed reasoning.

Re format, please do not use any fancy feature like named or positional parameter for now, this would require rather complex updates in i18n scripts. We have to ensure translated messages do not butcher the expected format parts (which happens very often already with the basic ones we currently support, and can easily lead Blender to crash when in C strings).
If we want to go that way, we first need to invest some dev time in our i18n tooling.

In D15615#445878, @Bastien Montagne (mont29) wrote:

Re format, please do not use any fancy feature like named or positional parameter for now

Duly noted, thanks! I wasn’t planning to do that any time soon, just noting that it is possible. If the need ever arises, I’ll make sure to consult and test before using such features. :)

I messed up the merging from the v3.4 branch to master and instead cherry-picked, but it will merge fine if someone makes a new commit and merges again to master.