nolimits4web/Framework7 — pull request #84 by gregkeys (2014-06-18 01:50:10+00:00)
Title: Added callback to preprocess 

This adds the ability to hold up page rendering until content is fully prepared making for a smoother experience vs switching to a blank page with a loading icon.

example usage as follows

```
var $$=Framework7.$,
myApp= new Framework7({
preprocess: function (content, url, callback) {
var xhr, template;
if(url == 'login.html') {
myApp.hideIndicator();
callback( content );
}
xhr = $$.ajax('someurl.html');
template = Handlebars.compile(content);

$$.when(xhr).then(function (data) {
if (data.code === 200) {
myApp.hideIndicator();
callback( template(data) );
}else if(data.code === 204){
myApp.hideIndicator();
myApp.allowPageChange = true;
mainView.loadPage('login.html');
}
});
}
});
```