How to export a to-do list?

My iPhone app, a goal-setting workshop, helps users build their own goal list.

I'd like to give my users an ability to export their goals as todo lists, so they can import them in 2do, Toodleo, Outlook, etc开发者_JAVA技巧.

Anybody got experience in this? I'm thinking of exporting into the Outlook format, or into iCal, or into Google Calendar, but I cannot find good libraries for that.

So - into what it is the best to export a to-do list, and what are some good iOS libraries for that?

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most natural to export a todo list, would be to consider first the vtodo component for icalendar files. You may however want to check compatibility with the targeted end-user client as a few years ago google calendar did not support vtodo. alternatively you can create them as simple vevent to secure it gets imported in end client application.