Accessing Soap Services from Google Gadgets

The earlier gadget projects I developed have utilized third-party web services from a variety of sources:

• Google Maps for geographic data
• Google Docs spreadsheet as XML datasource
  
• IP-Geolocation (IP address->Country) service from HostIP.Info
• User profile and gaming statistics as XML feeds from Xfire.

Given the constraints of a space-restricted, remotely-hosted, javascript-only application, gadgets primarily rely on web services to provide richer data content without the attendant complexity. However, javascript is beset by cross-domain restrictions that even impact xmlHttpRequest, the very underpinnings of Ajax. Since Google gadgets are javascript apps, the same-origin security policy prevents it from making requests outside the domain it is running on.

Although Google addressed this problem by providing the _IG_FetchXMLContent function, it lacks support for https, SOAP and POST. It looks like the newer gadget.io.makeRequest function is intended to address these deficiencies. However, the availability of the gadget.io.* functions in Google's production servers is yet forthcoming.

I decided not to hold my breath..

KT-Gadget is a widget front-end to KnowledgeTree - an open-source document management system. To access KnowledgeTree's SOAP services, I had to deploy another application to receive the requests from Google's _IG_FetchXMLContent calls, make the corresponding SOAP requests, and generate the appropriate XML output. Two basic functions are implemented: login and get_folder_contents. The functions are based on PHP, the same language that was used to develop KnowlegeTree.

After pushing the login button, the gadget will indicate the progress of the subsequent operations:

• Logging in
• Fetching Documents
• Sorting Documents

In its current state, the gadget is useful as a watcher of some sort of inbox for workflow-enabled documents like incoming faxes needing disposition or requisitions requiring approval. Sit around and watch your work pile up...

I plan to implement two more functions: download_document and perform_document_workflow_transition. We don't want work to pile up, do we? Other nice-to-have features: watch all accessible folders and sub-folders; show number of documents per folder; folder and document colors based on certain thresholds like document count, age, metadata contents (priority, etc); automatic refresh.

But don't hold your breath...

OpenID login for Knowledgetree

I have replaced (not integrated) KnowledgeTree authentication with OpenID. Supporting both default and OpenID authentication requires more work and that can come later.

This is by no means final since only limited testing has been performed so far. I've decided to post this in its raw form so I can solicit comments and suggestions from the community. And besides, my blog has not been updated for awhile now..

I'll detail the procedures here. I took notes but I may have missed something. Diligence is not one of my virtues..

• Copy login.php to login-orig.php (save original, let's modify login.php)
• Change template ktcore/login -> ktcore/openid
• Copy ./templates/ktcore/login.smarty to openid.smarty
  - change invocation of stylesheet kt-login.css -> kt-openid.css
  - change the Username prompt label to OpenID
  - add class="openid" to input tag for username
  - change name="username" to name="openid_url"
  - remove the password input field


• Download the OpenID logo
  
• Upload logo as openid-bg.png to ./resources/graphics
• Copy ./resources/css/kt-login.css to kt-openid.css
• Add input.openid to kt-openid.css, as follows:
  

  input.openid {
      border: 1px solid #666;
      width: 232px;
      background: url(../graphics/openid-bg.png) no-repeat;
      padding-left: 18px;
  }

Note the OpenID logo in the input field. This is implemented by the input.openid section of the stylesheet. I also changed the input field name to openid_url in conformance to OpenID specifications. I'm using Verisign PIP as OpenID Identity Provider and the Seatbelt browser plug-in kicks in only when openid_url is used as identifier.

I installed version 2.x.x of the PHP OpenID Library, as follows:

• Create the directory ./thirdparty/OpenID
• Copy the file common.php found in the examples directory. Also copy the Auth directory from the library.
• Add the following functions to common.php
  

  function fixslashes($s) {
      return get_magic_quotes_gpc() ? stripslashes($s) : $s;
  }
  
  function normOpenIDUrl($oid_url) {
      $claimed_id = strtolower (fixslashes($oid_url));
      $has_scheme = preg_match ('#^https\://#', $claimed_id) === 1;
      $has_scheme = $has_scheme || preg_match ('#^http\://#', $claimed_id) === 1;
      $has_tslash = preg_match ('#/$#', $claimed_id) === 1;
      return (($has_scheme?'':'http://') . $claimed_id . ($has_tslash?'':'/'));
  }

• Overwrite the original functions in common.php with these

  function getReturnTo() {
  return sprintf("%s://%s:%s/login.php",
                 getScheme(), $_SERVER['SERVER_NAME'],
                 $_SERVER['SERVER_PORT']);
  }
  
  function getTrustRoot() {
  return sprintf("%s://%s:%s/",
                 getScheme(), $_SERVER['SERVER_NAME'],
                 $_SERVER['SERVER_PORT']);
  }

• Change config/dmsDefaults.php to include the library in the path..

  $KTInit->prependPath(KT_DIR . '/thirdparty/OpenID');

The rest of the changes are in login.php, the source of which can be found here.

I've disabled automatic sign-up so make sure to create an OpenID account with Administrator privileges before you apply the changes. To prevent duplicate accounts, the usernames are OpenID URLs in normalized form (with leading http:// and trailing /). Thus, the username http://pipoltek.blogspot.com/ applies to any of the following acceptable OpenID identity URLs:

• pipoltek.blogspot.com
• http://pipoltek.blogspot.com
• http://pipoltek.blogspot.com/

I've successfully authenticated using my OpenID accounts from Blogspot, Technorati and Verisign PIP. However, I had login failures using my Yahoo OpenID and a delegate identity URL.

My testbed:

• VMWare Server version 1.0.4.56528
• KnowledgeTree OSS 3.4.2 VM Appliance from rPath
• Microsoft Windows XP Home Service Pack 2
• Mozilla Firefox 2.0.0.14