Fix django auth login redirection

The django authentication decorator login_required, redirects to
settings.LOGIN_URL. If it is missing, it redirects to /accounts/login.

We did not have the setting enable, not a proper page where to
redirect. This cause users not logged in to see a 404 error when
accessing courseware directly, by using a link or a bookmark.

[#41499213]

common/djangoapps/student/views.py

@@ -333,6 +333,18 @@ def change_enrollment(request):
     return {'success': False, 'error': 'We weren\'t able to unenroll you. Please try again.'}
 
 
+@ensure_csrf_cookie
+def accounts_login(request, error=""):
+
+    return_to = ''
+
+    return render_to_response('accounts_login.html', {
+        'error': error,
+        'return_to': return_to
+    })
+
+
+
 # Need different levels of logging
 @ensure_csrf_cookie
 def login_user(request, error=""):

lms/envs/common.py

@@ -187,6 +187,9 @@ DEBUG_TRACK_LOG = False
 
 MITX_ROOT_URL = ''
 
+LOGIN_REDIRECT_URL = MITX_ROOT_URL + '/accounts/login'
+LOGIN_URL = MITX_ROOT_URL + '/accounts/login'
+
 COURSE_NAME = "6.002_Spring_2012"
 COURSE_NUMBER = "6.002x"
 COURSE_TITLE = "Circuits and Electronics"

lms/templates/accounts_login.html

+<%! from django.core.urlresolvers import reverse %>
+<%inherit file="main.html" />
+<%namespace name='static' file='static_content.html'/>
+
+<%block name="headextra">
+<style type="text/css">
+.login-box {
+    display: block;
+    position: relative;
+    left: 0;
+    margin: 100px auto;
+    top: 0;
+    z-index: 200;
+}
+
+.login-box input[type=submit] {
+    white-space: normal;
+    height: auto !important;
+}
+
+#lean_overlay {
+  display: block;
+  position: fixed;
+  left: 0px;
+  top: 0px;
+  z-index: 100;
+  width:100%;
+  height:100%;
+}
+</style>
+</%block>
+
+<section id="login-modal" class="modal login-modal login-box">
+  <div class="inner-wrapper">
+    <header>
+      <h2>Log In</h2>
+      <hr>
+    </header>
+
+    <form id="login_form" class="login_form" method="post" data-remote="true" action="/login">
+      <label>E-mail</label>
+      <input name="email" type="email">
+      <label>Password</label>
+      <input name="password" type="password">
+      <label class="remember-me">
+        <input name="remember" type="checkbox" value="true">
+        Remember me
+      </label>
+      <div class="submit">
+        <input name="submit" type="submit" value="Access My Courses">
+      </div>
+    </form>
+
+    <section class="login-extra">
+      <p>
+        <span>Not enrolled? <a href="#signup-modal" class="close-login" rel="leanModal">Sign up.</a></span>
+        <a href="#forgot-password-modal" rel="leanModal" class="pwd-reset">Forgot password?</a>
+      </p>
+% if settings.MITX_FEATURES.get('AUTH_USE_OPENID'):
+      <p>
+      <a href="${MITX_ROOT_URL}/openid/login/">login via openid</a>
+      </p>
+% endif
+    </section>
+
+    <div class="close-modal">
+      <div class="inner">
+        <p>&#10005;</p>
+      </div>
+    </div>
+  </div>
+</section>
+
+<script type="text/javascript">
+(function() {
+   $(document).delegate('#login_form', 'ajax:success', function(data, json, xhr) {
+     if(json.success) {
+        next = getParameterByName('next');
+        if(next) {
+           location.href = next;
+       } else {
+           location.href = "${reverse('dashboard')}";
+       }
+     } else {
+       if($('#login_error').length == 0) {
+         $('#login_form').prepend('<div id="login_error" class="modal-form-error"></div>');
+       }
+       $('#login_error').html(json.value).stop().css("display", "block");
+     }
+   });
+})(this)
+</script>

lms/urls.py

@@ -37,6 +37,8 @@ urlpatterns = ('',
     url(r'^event$', 'track.views.user_track'),
     url(r'^t/(?P<template>[^/]*)$', 'static_template_view.views.index'), # TODO: Is this used anymore? What is STATIC_GRAB?
 
+    url(r'^accounts/login$', 'student.views.accounts_login', name="accounts_login"),
+
     url(r'^login$', 'student.views.login_user', name="login"),
     url(r'^login/(?P<error>[^/]*)$', 'student.views.login_user'),
     url(r'^logout$', 'student.views.logout_user', name='logout'),