forme 3.0.0-beta+1

a powerful flutter form widget ,easy to use and extend. provide rich api to simplify form control and sync|async validation

Forme3

Forme3 is not an upgrade version but a simple version of Forme2

differences:

1. Forme3 removed model which used to provide render data in Forme2 and moved model properties into field's constructor
2. Forme3 removed listener from field's constructor and moved listener properties into field's constructor
3. Forme3 removed CommonField and renamed ValueField to FormeField
4. Forme3 has big api breaks