chrispittman/lti1-php

This package is abandoned and no longer maintained. No replacement package was suggested.

Utility tools for LTI 1.x interactions

Maintainers

Details

github.com/chrispittman/lti1_php

Source

Issues

Installs: 43

Dependents: 0

Suggesters: 0

Security: 0

Stars: 0

Watchers: 1

Forks: 1

Open Issues: 0

1.1.1 2019-09-06 08:57 UTC

Requires

MIT 9eac0187d817feee036469ea2b468ac9116151f6

LTI

This package is not auto-updated.

Last update: 2020-09-22 14:50:24 UTC

README

Composer package for LTI 1.x interactions in PHP

Usage example

Here's a sample Laravel controller which uses this to launch an LTI app.

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use Chrispittman\Lti1\LTIUtils;
use App;
use Cache;
use Redirect;
use Session;

class LTIController extends Controller
{
    // assumes these routes are present:
    // Route::post('/lti_launch', 'LTIController@postLaunch');
    // Route::get('/lti_redirect', 'LTIController@getRedirect');
    // Route::get('/lti_tool', 'LTIController@getTool');

    public function postLaunch(Request $request) {
        $lti_utils = new LTIUtils();
        if (!$lti_utils->is_basic_lti_request()) {
            App::abort(403,"Not a basic LTI request.");
        }
        $consumer_key = $request->get('oauth_consumer_key');
        $shared_secret = STORED_SHARED_SECRET_HERE;
        if (!$lti_utils->is_valid_oauth_signature($consumer_key, $shared_secret, $request->url())) {
            App::abort(403,"Invalid OAuth signature.");
        }

        $request->session()->put('lti_launch_data', $_POST);

        $uuid = self::gen_uuid();
        Cache::put('lti_launch_data_' . $uuid, $_POST, 5);

        $launch_url = "/lti_redirect?uuid=".$uuid;
        return Redirect::to($launch_url);
    }

    public function getRedirect(Request $request) {
        // * What is this?
        // * Why not just use the data in the session?
        // * Why not just redirect straight to the tool?
        // Sessions are tricky with iframes, which many LMSes put tools inside of:
        // http://www.dr-chuck.com/csev-blog/2013/03/lti-frames-and-cookies-oh-my/
        // ...so we use the cache as a temporary holding area until we have a working session,
        // popping open a new window if needed.
        $uuid = $_REQUEST['uuid'];
        $tool_start_page = "/lti_tool";
        if (Session::has('lti_launch_data')) {
            return Redirect::to('/lti_tool');
        }
        if ($request->has('newwin')) {
            Session::put('lti_launch_data', Cache::get('lti_launch_data_' . $uuid));
            return Redirect::to('/lti_tool');

        }
        return "<html><body><br><br><br><div style='text-align:center;font-family:sans-serif;font-size:200%;'><a href='".$request->fullUrl()."&newwin=true' target='_blank'>Click here to load this page.</a></div></body></html>";
    }

    public function getTool(Request $request) {
        return "Here's the first page of the tool. <br><br> ".json_encode(Session::get('lti_launch_data'));
    }

    protected static function gen_uuid() {
        return sprintf( '%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
            // 32 bits for "time_low"
            mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ),
            // 16 bits for "time_mid"
            mt_rand( 0, 0xffff ),
            // 16 bits for "time_hi_and_version",
            // four most significant bits holds version number 4
            mt_rand( 0, 0x0fff ) | 0x4000,
            // 16 bits, 8 bits for "clk_seq_hi_res",
            // 8 bits for "clk_seq_low",
            // two most significant bits holds zero and one for variant DCE1.1
            mt_rand( 0, 0x3fff ) | 0x8000,
            // 48 bits for "node"
            mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff )
        );
    }
}