I'm having an issue that is driving me crazy. I'm trying to modify the openid-selector to support facebook. I'm using RPXNow as my provider so it requires the form to be submitted to a different url than the standard.

For example. RpxNow requires me to setup my form like this:

<form action="https://wikipediamaze.rpxnow.com/openid/start?token_url=...">

This works for every provider except for facebook and myspace. Those require the form to be posted to a different url like this:

<form action="https://wikipediamaze.rpxnow.com/facebook/start?token_url=...">

and

<form action="https://wikipediamaze.rpxnow.com/myspace/start?token_url=...">

The open id selector has a bunch of buttons on the form each representing the openid providers. What I'm trying to do is detect when the facebook or myspace button is clicked and changed the action on the form before submitting. However it's not working. Here is my code.

I've tried several variations all with the same "not supported" exception

$("#openid_form").attr("action", form_url)
document.forms[0].action = form_url

Any suggestions?

Update

Here are more details on the code. I've ommitted some for brevity. The only thing i've done is added the facebook section to the "providers_large" object (which successfully adds the logo to the website), and instead of supply a url identifying the user, I'm creating a property called "form_url" which is what I want to set the action of my form to. If you look at the section title "Provider image click" you'll see where I'm checking for the presence of the property "form_url" and using jquery to change the action and submit the form. However when I step through the javascript in debug mode it tells me it's an ivalid operation.

var providers_large = {
    google: {
        name: 'Google',
        url: 'https://www.google.com/accounts/o8/id'
    },
    facebook: {
        name: 'Facebook',
        form_url: 'http://wikipediamaze.rpxnow.com/facebook/start?token_url=http://www.wikipediamaze.com/Accounts/Logon'
    },

};
var providers_small = {
    myopenid: {
        name: 'MyOpenID',
        label: 'Enter your MyOpenID username.',
        url: 'http://{username}.myopenid.com/'
    },
    livejournal: {
        name: 'LiveJournal',
        label: 'Enter your Livejournal username.',
        url: 'http://{username}.livejournal.com/'
    },
    flickr: {
        name: 'Flickr',        
        label: 'Enter your Flickr username.',
        url: 'http://flickr.com/{username}/'
    },
    technorati: {
        name: 'Technorati',
        label: 'Enter your Technorati username.',
        url: 'http://technorati.com/people/technorati/{username}/'
    },
    wordpress: {
        name: 'Wordpress',
        label: 'Enter your Wordpress.com username.',
        url: 'http://{username}.wordpress.com/'
    },
    blogger: {
        name: 'Blogger',
        label: 'Your Blogger account',
        url: 'http://{username}.blogspot.com/'
    },
    verisign: {
        name: 'Verisign',
        label: 'Your Verisign username',
        url: 'http://{username}.pip.verisignlabs.com/'
    },
    vidoop: {
        name: 'Vidoop',
        label: 'Your Vidoop username',
        url: 'http://{username}.myvidoop.com/'
    },
    verisign: {
        name: 'Verisign',
        label: 'Your Verisign username',
        url: 'http://{username}.pip.verisignlabs.com/'
    },
    claimid: {
        name: 'ClaimID',
        label: 'Your ClaimID username',
        url: 'http://claimid.com/{username}'
    }
};
var providers = $.extend({}, providers_large, providers_small);

var openid = {

        cookie_expires: 6*30,   // 6 months.
        cookie_name: 'openid_provider',
        cookie_path: '/',

        img_path: 'images/',

        input_id: null,
        provider_url: null,

    init: function(input_id) {

        var openid_btns = $('#openid_btns');

        this.input_id = input_id;

        $('#openid_choice').show();
        $('#openid_input_area').empty();

        // add box for each provider
        for (id in providers_large) {

                openid_btns.append(this.getBoxHTML(providers_large[id], 'large', '.gif'));
        }
        if (providers_small) {
                openid_btns.append('<br/>');

                for (id in providers_small) {

                        openid_btns.append(this.getBoxHTML(providers_small[id], 'small', '.ico'));
                }
        }

        $('#openid_form').submit(this.submit);

        var box_id = this.readCookie();
        if (box_id) {
                this.signin(box_id, true);
        }  
    },
    getBoxHTML: function(provider, box_size, image_ext) {

        var box_id = provider["name"].toLowerCase();
        return '<a title="'+provider["name"]+'" href="javascript: openid.signin(\''+ box_id +'\');"' +
                        ' style="background: #FFF url(' + this.img_path + box_id + image_ext+') no-repeat center center" ' + 
                        'class="' + box_id + ' openid_' + box_size + '_btn"></a>';    

    },
    /* Provider image click */
    signin: function(box_id, onload) {

        var provider = providers[box_id];
                if (! provider) {
                        return;
                }

                this.highlight(box_id);
                this.setCookie(box_id);

                // prompt user for input?
                if (provider['label']) {

                        this.useInputBox(provider);
                        this.provider_url = provider['url'];

                } 
                else if(provider['form_url']) {

                        $('#openid_form').attr("action", provider['form_url']);
                        $('#openid_form').submit();
                }
                else {

                        this.setOpenIdUrl(provider['url']);
                        if (! onload) {
                                $('#openid_form').submit();
                        }       
                }
    },
    /* Sign-in button click */
    submit: function() {

        var url = openid.provider_url; 
        if (url) {
                url = url.replace('{username}', $('#openid_username').val());
                openid.setOpenIdUrl(url);
        }
        return true;
    },
    setOpenIdUrl: function (url) {

        var hidden = $('#'+this.input_id);
        if (hidden.length > 0) {
                hidden.value = url;
        } else {
                $('#openid_form').append('<input type="hidden" id="' + this.input_id + '" name="' + this.input_id + '" value="'+url+'"/>');
        }
    },
    highlight: function (box_id) {

        // remove previous highlight.
        var highlight = $('#openid_highlight');
        if (highlight) {
                highlight.replaceWith($('#openid_highlight a')[0]);
        }
        // add new highlight.
        $('.'+box_id).wrap('<div id="openid_highlight"></div>');
    },
    setCookie: function (value) {

                var date = new Date();
                date.setTime(date.getTime()+(this.cookie_expires*24*60*60*1000));
                var expires = "; expires="+date.toGMTString();

                document.cookie = this.cookie_name+"="+value+expires+"; path=" + this.cookie_path;
    },
    readCookie: function () {
                var nameEQ = this.cookie_name + "=";
                var ca = document.cookie.split(';');
                for(var i=0;i < ca.length;i++) {
                        var c = ca[i];
                        while (c.charAt(0)==' ') c = c.substring(1,c.length);
                        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
                }
                return null;
    },
    useInputBox: function (provider) {

                var input_area = $('#openid_input_area');

                var html = '';
                var id = 'openid_username';
                var value = '';
                var label = provider['label'];
                var style = '';

                if (label) {
                        html = '<p>' + label + '</p>';
                }
                if (provider['name'] == 'OpenID') {
                        id = this.input_id;
                        value = 'http://';
                        style = 'background:#FFF url('+this.img_path+'openid-inputicon.gif) no-repeat scroll 0 50%; padding-left:18px;';
                }
                html += '<input id="'+id+'" type="text" style="'+style+'" name="'+id+'" value="'+value+'" />' + 
                                        '<input id="openid_submit" type="submit" value="Sign-In"/>';

                input_area.empty();
                input_area.append(html);

                $('#'+id).focus();
    }
};