DoC Computing Support Group


What is a TextCHA?

It is a pure text alternative to CAPTCHAs. MoinMoin uses it to prevent wiki spamming.

Features:

  • for page save, ask a random question
  • match the given answer against a regular expression
  • q and a can be configured in the wiki config
  • multi language support: a user gets a textcha in his language or in language_default or in English (depending on availability of questions/answers for the language)

Tips for answering:

  • you need to answer the textcha for e.g.:
    • page save
    • attachment upload
    • user profile creation
  • you do not need to answer the textcha for e.g.:
    • page preview (if you do, it will remember what you entered, though)
    • user profile changes
  • it is usually a simple/short answer
  • it compares case-insensitive
  • sometimes you can find the right answer by reading some important pages of the wiki

Configuration

Tips for configuration:

  • have 1 word / 1 number answers
  • ask questions that normal users of your site are likely to be able to answer
  • do not ask too hard questions
  • do not ask "computable" questions, like "1+1" or "2*3"
  • do not ask too common questions
  • do not share your questions with other sites / copy questions from other sites (or spammers might try to adapt to this)
  • you should at least give textchas for 'en' (or for your language_default, if that is not 'en') as this will be used as fallback if MoinMoin does not find a textcha in the user's language

In your wiki config, do something like this:

    textchas_disabled_group = u"TrustedEditorGroup" # members of this don't get textchas
    textchas = {
        'en': { # silly english example textchas (do not use them!)
            u"Enter the first 9 digits of Pi.": ur"3\.14159265",
            u"What is the opposite of 'day'?": ur"(night|nite)",
            # ...
        },
        'de': { # some german textchas
            u"Gib die ersten 9 Stellen von Pi ein.": ur"3\.14159265",
            u"Was ist das Gegenteil von 'Tag'?": ur"nacht",
            # ...
        },
        # you can add more languages if you like
    }