The directive doens't work with "data-" prefix

[TomasRup]

It works this way: <div date-picker></div>

But doesn't work like this (which is supposed to be more valid): <div data-date-picker></div>

[DanTalash]

Looks like the library is functional when used with data-date-picker, but the styles are not being applied because they are being targeted at a date-picker attribute instead of a class. See plunkr.