I am new to Sencha Touch, and wonder how page navigation works.
so far, the best i found was something like:
var redirect = 'page2.html';
window.location = redirect;
and to prevent unnecessary fetching, cache all .js and style using app.manifest.
Any recommendation? Is there a way similar to page navigation in JQuery mobile?
As far as I'm aware, Sencha Touch does not support page navigation the way jQuery mobile does.
If you really have to redirect (and make a page refresh), then I believe the only way of doing it is the way you have described (window.location).
However, in Sencha Touch, there is often no need to do redirects. You could easy create a fullscreen Panel, and then change the content of this panel dynamically (i.e. navigate to a page). Have a look at one of the examples, to get the idea:
http://dev.sencha.com/deploy/touch/examples/oreilly/