https://api.login.yahoo.com/oauth/v2/request_auth?oauth_token=....

var YahooWebView = Ti.UI.createWebView({
left : 0,
    top : 0,
    right : 0,
    bottom : 0,
    width : 320,
    height : 568,
    scalesPageToFit : true,
    url : "http://example.com"
});

var authPageURL = "https://api.login.yahoo.com/oauth/v2/request_auth?oauth_token=" + oauthToken;
var yahooMobileLoginUrl = "https://login.yahoo.com/m?&.src=oauth&.lang=en-us&.intl=us&.done=" + authPageURL;
YahooWebView.setUrl(yahooMobileLoginUrl);