js2prop.py

#  -*- coding: utf-8 -*-
# js2prop.py: App Inventor 2 (AI2) translation helper
# Split _messages.js into a preamble, a properties file (usable with po2prop) and a postamble
# 
# The properties are represented as assignments in the .js file:
#     Blockly.Msg.LANG_LISTS_LOOKUP_IN_PAIRS_INPUT = "parvis uppslagning  nyckel %1 par %2 hittadesInte %3"
#
# In the .properties file this corresponds to
#     Blockly.Msg.LANG_LISTS_LOOKUP_IN_PAIRS_INPUT = parvis uppslagning  nyckel %1 par %2 hittadesInte %3
#
# See https://github.com/mit-cml/appinventor-sources/blob/master/appinventor/blocklyeditor/src/msg/sv/_messages.js
# Thanks to https://jis.qyv.name/ for helping out

import re
from sys import argv

def quote_leading_space(s):
   if len(s) == 0 or s[0] != ' ':
       return s
   return '\\' + s

def main():
    script, filename = argv
    files = ['1-pre-' + filename, '2-' + filename + '.properties', '3-post-' + filename]
    preamble, properties, postamble = 0, 1, 2
    fileCount = preamble

    target = open(files[fileCount], 'w')
    target.truncate()
    p = re.compile(r'(Blockly[^\s=]+)\s=\s\"(.*)"$', re.IGNORECASE)

    with open(filename, encoding='utf-8') as inf:
        for line in inf:
            if fileCount == preamble:
                m = p.search(line)
                if m:
                    target.close()
                    fileCount = properties
                    target = open(files[fileCount], 'w', encoding='utf-8')
                    target.truncate()
                else:
                    target.write(line)
            if fileCount == properties:
                m = p.search(line)
                if m:
                    target.write(''.join([m.group(1), ' = ', quote_leading_space(m.group(2)), '\n']))
                else:           
                    target.close()
                    fileCount = postamble
                    target = open(files[fileCount], 'w')
                    target.truncate()
            if fileCount == postamble:
                target.write(line)

if __name__ == "__main__":
    main()