• 实时语言切换
    • 问题:
    • 解法:

    实时语言切换

    问题:

    如何实现实时语言切换？

    解法:

    • 首先你必须阅读 模板语言中的i18n支持, 然后尝试下面的代码。文件: code.py
    1. import os
    2. import sys
    3. import gettext
    4. import web
    6. # File location directory.
    7. rootdir = os.path.abspath(os.path.dirname(__file__))
    9. # i18n directory.
    10. localedir = rootdir + '/i18n'
    12. # Object used to store all translations.
    13. allTranslations = web.storage()
    15. def get_translations(lang='en_US'):
    16.     # Init translation.
    17.     if allTranslations.has_key(lang):
    18.         translation = allTranslations[lang]
    19.     elif lang is None:
    20.         translation = gettext.NullTranslations()
    21.     else:
    22.         try:
    23.             translation = gettext.translation(
    24.                     'messages',
    25.                     localedir,
    26.                     languages=[lang],
    27.                     )
    28.         except IOError:
    29.             translation = gettext.NullTranslations()
    30.     return translation
    32. def load_translations(lang):
    33.     """Return the translations for the locale."""
    34.     lang = str(lang)
    35.     translation  = allTranslations.get(lang)
    36.     if translation is None:
    37.         translation = get_translations(lang)
    38.         allTranslations[lang] = translation
    40.         # Delete unused translations.
    41.         for lk in allTranslations.keys():
    42.             if lk != lang:
    43.                 del allTranslations[lk]
    44.     return translation
    46. def custom_gettext(string):
    47.     """Translate a given string to the language of the application."""
    48.     translation = load_translations(session.get('lang'))
    49.     if translation is None:
    50.         return unicode(string)
    51.     return translation.ugettext(string)
    53. urls = (
    54.     '/', 'index'
    55. )
    57. render = web.template.render('templates/',
    58.         globals={
    59.             '_': custom_gettext,
    60.             }
    61.         )
    63. app = web.application(urls, globals())
    65. # Init session.
    66. session = web.session.Session(app,
    67.         web.session.DiskStore('sessions'),
    68.         initializer={
    69.             'lang': 'en_US',
    70.             }
    71.         )
    73. class index:
    74.     def GET(self):
    75.         i = web.input()
    76.         lang = i.get('lang', 'en_US')
    78.         # Debug.
    79.         print >> sys.stderr, 'Language:', lang
    81.         session['lang'] = lang
    82.         return render.index()
    84. if __name__ == "__main__": app.run()

    模板文件: templates/index.html.

    1. $_('Hello')

    不要忘记生成必要的po&mo语言文件。参考: 模板语言中的i18n支持

    现在运行code.py:

    1. $ python code.py
    2. http://0.0.0.0:8080/

    然后用你喜欢的浏览器访问下面的地址，检查语言是否改变:

    1. http://your_server:8080/
    2. http://your_server:8080/?lang=en_US
    3. http://your_server:8080/?lang=zh_CN

    你必须:

    • 确保语言文件(en_US、zh_CN等)可以动态改变。

    • 确保custom_gettext()调用越省资源越好。参考:

    • 这里有使用app.app_processor()的 另一个方案。