In fact, not every function is callable via Ur/Web JS FFI. Same is true for the C FFI as well. Ur/Web may not always have correct representations for specific types of arguments anr/or return values of a JS function. To address this, you may write your own JavaSript file containing wrapper functions which you know are 100% callable, which would translate Ur/Web data into data required by your target library. Urweb-persona library may be a nice example of the approach. This lib contains code which not only calls third-party Persona JS functions, but also passes Ur/Web callbacks there.
Regards, Sergey 2015-08-02 4:45 GMT+03:00 Stefan Scott Alexander <[email protected]>: > I understand that it is necessary to use Ur/Web's JavaScript FFI in order to > call an existing JavaScript library, and I have to declare the functions in > a URS file. > > The difficulty I have is that when I look at certain JavaScript libraries, I > have difficulty determining what functions are at "top-level" in the JS > file, to declare in the URS file. > > For example, here are two JavaScript libraries which implement a DatePicker: > > https://github.com/eternicode/bootstrap-datepicker/blob/master/js/bootstrap-datepicker.js > > https://github.com/dbushell/Pikaday/blob/master/pikaday.js > > They both appear to have a single top-level "factory" function (?), > apparently anonymous (?), enclosed in parentheses. > > Then they both return a bunch of things in { ... } - var declarations and > function declarations etc. But these things aren't at "top-level" so I doubt > it would make much sense to refer to such function declarations from a URS > file. > > Are these kind of JavaScript libraries (involving a single, anonymous > top-level function) even callable via Ur/Web's FFI? > > _______________________________________________ > Ur mailing list > [email protected] > http://www.impredicative.com/cgi-bin/mailman/listinfo/ur > _______________________________________________ Ur mailing list [email protected] http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
