Show sensible error message for failed login

- Issue #576 - Use of twisted templating
author: Folker Bernitt <fbernitt@thoughtworks.com> 2016-01-22 17:42:35 +0100
committer: Folker Bernitt <fbernitt@thoughtworks.com> 2016-01-22 17:43:21 +0100
commit: 18123f6745beaba99b40a4db6d9aad1dbcdf6925 (patch)
tree: 037465bfdcd0825a3142d23339ed383b1bc23633 /service
parent: dacc69ea5cc3a35faf05a95e8976cd9a1fdec621 (diff)
2 files changed, 55 insertions, 34 deletions
diff --git a/service/pixelated/assets/login.html b/service/pixelated/assets/login.html
index 734fffd0..d59ac4cd 100644
--- a/service/pixelated/assets/login.html
+++ b/service/pixelated/assets/login.html
@@ -1,25 +1,29 @@
 <!DOCTYPE html>
-<html>
+<html xmlns:t="http://twistedmatrix.com/ns/twisted.web.template/0.1">
 <head>
     <title>Pixelated - Login</title>
-    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
-    <link rel="icon" type="image/png" href="/startup-assets/favicon.png">
-    <link rel="stylesheet" type="text/css" href="/startup-assets/normalize.min.css">
-    <link rel="stylesheet" type="text/css" href="/startup-assets/pixelated.css">
-    <link rel="stylesheet" type="text/css" href="/startup-assets/opensans.css">
+    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+    <link rel="icon" type="image/png" href="/startup-assets/favicon.png" />
+    <link rel="stylesheet" type="text/css" href="/startup-assets/normalize.min.css" />
+    <link rel="stylesheet" type="text/css" href="/startup-assets/pixelated.css" />
+    <link rel="stylesheet" type="text/css" href="/startup-assets/opensans.css" />
 </head>
 <body>
 <div class="content">
     <div class="login">
 
-        <img class="logo" src="/startup-assets/pixelated-logo-orange.svg" alt="Pixelated logo" />
+        <img class="logo" src="/startup-assets/pixelated-logo-orange.svg" alt="Pixelated logo"/>
+
+        <p t:render="error_msg" class="error" ></p>
 
 
         <form class="standard" id="login_form" action="/login" method="post">
-            <input type="text" name="username" id="email" class="text-field" placeholder="  username" tabindex="1" autofocus>
-            <input type="password" name="password" id="password" class="text-field" placeholder="  password" tabindex="2" autocomplete="off">
+            <input type="text" name="username" id="email" class="text-field" placeholder="  username" tabindex="1"
+                   autofocus="" />
+            <input type="password" name="password" id="password" class="text-field" placeholder="  password"
+                   tabindex="2" autocomplete="off" />
 
-            <input type="submit" name="login" value="Login" class="button" tabindex="3">
+            <input type="submit" name="login" value="Login" class="button" tabindex="3" />
 
         </form>
     </div>
diff --git a/service/pixelated/resources/login_resource.py b/service/pixelated/resources/login_resource.py
index b249a67e..e7586bf6 100644
--- a/service/pixelated/resources/login_resource.py
+++ b/service/pixelated/resources/login_resource.py
@@ -16,26 +16,58 @@
 
 import logging
 import os
-from string import Template
 
 from twisted.cred import credentials
 from twisted.internet import defer
 from twisted.web.resource import IResource
 from twisted.web.server import NOT_DONE_YET
 from twisted.web.static import File
+from twisted.web.template import Element, XMLFile, renderElement, renderer, tags
+from twisted.python.filepath import FilePath
 
 from pixelated.resources import BaseResource, UnAuthorizedResource
 
 log = logging.getLogger(__name__)
 
 
+def _get_startup_folder():
+    path = os.path.dirname(os.path.abspath(__file__))
+    return os.path.join(path, '..', 'assets')
+
+
+def _get_static_folder():
+    static_folder = os.path.abspath(os.path.join(os.path.abspath(__file__), "..", "..", "..", "web-ui", "app"))
+    # this is a workaround for packaging
+    if not os.path.exists(static_folder):
+        static_folder = os.path.abspath(
+            os.path.join(os.path.abspath(__file__), "..", "..", "..", "..", "web-ui", "app"))
+    if not os.path.exists(static_folder):
+        static_folder = os.path.join('/', 'usr', 'share', 'pixelated-user-agent')
+    return static_folder
+
+
+class LoginWebSite(Element):
+    loader = XMLFile(FilePath(os.path.join(_get_startup_folder(), 'login.html')))
+
+    def __init__(self, error_msg=None):
+        super(LoginWebSite, self).__init__()
+        self._error_msg = error_msg
+
+    @renderer
+    def error_msg(self, request, tag):
+        if self._error_msg is not None:
+            return tag(self._error_msg)
+        else:
+            return tag('')
+
+
 class LoginResource(BaseResource):
     BASE_URL = 'login'
 
     def __init__(self, services_factory, portal=None):
         BaseResource.__init__(self, services_factory)
-        self._static_folder = self._get_static_folder()
-        self._startup_folder = self._get_startup_folder()
+        self._static_folder = _get_static_folder()
+        self._startup_folder = _get_startup_folder()
         self._html_template = open(os.path.join(self._startup_folder, 'login.html')).read()
         self._portal = portal
         self.putChild('startup-assets', File(self._startup_folder))
@@ -51,8 +83,11 @@ class LoginResource(BaseResource):
         return UnAuthorizedResource()
 
     def render_GET(self, request):
-        response = Template(self._html_template).safe_substitute()
-        return str(response)
+        return self._render_template(request)
+
+    def _render_template(self, request, error_msg=None):
+        site = LoginWebSite(error_msg=error_msg)
+        return renderElement(request, site)
 
     def render_POST(self, request):
 
@@ -61,12 +96,8 @@ class LoginResource(BaseResource):
             request.finish()
 
         def render_error(error):
-            login_form = self.render_GET(request)
             request.status = 500
-            request.write('We got an error:\n')
-            request.write(str(error))
-            request.write(login_form)
-            request.finish()
+            return self._render_template(request, 'Invalid credentials')
 
         d = self._handle_login(request)
         d.addCallbacks(render_response, render_error)
@@ -90,17 +121,3 @@ class LoginResource(BaseResource):
         leap_user.init_http_session(request)
 
         log.info('about to redirect to home page')
-
-    def _get_startup_folder(self):
-        path = os.path.dirname(os.path.abspath(__file__))
-        return os.path.join(path, '..', 'assets')
-
-    def _get_static_folder(self):
-        static_folder = os.path.abspath(os.path.join(os.path.abspath(__file__), "..", "..", "..", "web-ui", "app"))
-        # this is a workaround for packaging
-        if not os.path.exists(static_folder):
-            static_folder = os.path.abspath(
-                os.path.join(os.path.abspath(__file__), "..", "..", "..", "..", "web-ui", "app"))
-        if not os.path.exists(static_folder):
-            static_folder = os.path.join('/', 'usr', 'share', 'pixelated-user-agent')
-        return static_folder
author	Folker Bernitt <fbernitt@thoughtworks.com>	2016-01-22 17:42:35 +0100
committer	Folker Bernitt <fbernitt@thoughtworks.com>	2016-01-22 17:43:21 +0100
commit	18123f6745beaba99b40a4db6d9aad1dbcdf6925 (patch)
tree	037465bfdcd0825a3142d23339ed383b1bc23633 /service
parent	dacc69ea5cc3a35faf05a95e8976cd9a1fdec621 (diff)