IE8 and the Activities Feature for Developers

The IE8 Features for developers is pretty impressive. Heres is a bit on the "Activities" Feature.

Activities

This should probably have a better name for developers, something like "open service". (ed. Its actually called OpenService and there is a proposed extension on the MicroFormats Wiki. ) The IE8 feature allows a developer to embed a web service into the HTML page. If you're familiar with Open Search, this is a very similar protocol for embedding any service into a HTML page and follows the same technique.

Open Search is an XML format for mapping out query URLs for Search Engines. EG:

<?xml version="1.0" encoding="UTF-8"?>
 <OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/">
   <ShortName>Web Search</ShortName>
   <Description>Use Example.com to search the Web.</Description>
   <Tags>example web</Tags>
   <Contact>[email protected]</Contact>
   <Url type="application/rss+xml" 
        template="http://example.com/?q={searchTerms}&pw={startPage?}&format=rss"/>
 </OpenSearchDescription>

This then allows an Open Search Client such as the browser to make a Search Request based on the XML provided for a Search Engine Service. This is what is used each time you type a search into the little search bar on the top right in Firefox or IE.

IE8 feeds of a similar XML schema for its Activities - which maps out queries for web services, I'd guess RESTFUL webservices. EG:

<?xml version="1.0" encoding="UTF-8"?>
  <openServiceDescription xmlns=”http://www.microsoft.com/schemas/openservicedescription/1.0”>
  <homepageUrl>http://maps.live.com</homepageUrl>
  <display>
    <name>Map with Windows Live</name>
    <icon>http://www.live.com/favicon.ico</icon>
  </display>
  <activity category=”map”>
    <activityAction context=”selection”>
      <preview action= ”http://maps.live.com/geotager.aspx">
        <parameter name="b" value="{selection}"/>
        <parameter name="clean" value="true"/>
        <parameter name="w" value="320"/>
        <parameter name="h" value="240"/>
        </preview>
      <execute action="http://maps.live.com/default.aspx">
        <parameter name="where1" value="{selection}" type="text" />
      </execute>
    </activityAction>
  </activity>
</openServiceDescription>

Unfortunately following the namespace for the openServiceDescription XML document yields an equivalent of a 404 page. Wow Microsoft, nice documentation. Guess you'll have to Google it.

You may or may not be aware that this is a standardization of a number of existing data formats and widgets used to display exactly the same thing, links that enable you to add a piece of HTML directly to an external web service.

Generally, a developer develops a web service, they have to syndicate that service some how. They have choices such as JSON, RSS, ATOM, or AJAX widgets etc. The problems with these is that it does not allow an external service to make a dynamic request or query to their service in a standard way. Open Search was developed to standardize this for Search Engines. Now it looks like Microsoft has come up a similar standard for general web service.

The key difference between a standardized format for querying a web service and the web service description provided by the web service itself is simplicity. You can query any web service if you have the technical expertize to read the documentation, and implement a web service request and consume its response. However, you cannot implement the description of one web service directly to another unless you have a standard description for querying both - Open Service Description.

In other words, this is how IE8/Microsoft aims to have web services come to them, instead of having to go out and implement every web service description out there, developers of web services will be sending their Open Service Descriptions to IE8.

As a developer, this is good news. Now you can hitch a ride with IE8, consume any web service descriptions designed for IE8 and implement them into your own mashups, website, webapp or web service.

Open source, distributed, multi-platform, web browser screenshots!

If you're an XHTML and CSS designer you've had the problem where your beautiful design breaks in different browsers. Therefore, you have to recheck your designs in the major browsers. I normally go with IE6+ and Firefox 1.5+.

Due to the huge number of different browsers out there on different Operating Systems, it usually isn't possible to have access to each browser/OS configuration. That is why many designers use as services such as browsercam.com; which is a paid service that generates screenshots of web pages in different browsers running on different operating systems.

Today while looking for alternatives I stumbled upon http://browsershots.org/. This is an Open Source service that takes screenshots of web pages in different browsers and Operating Systems on distributed computers working together via XML-RPC. Contributers to the service register as Screenshot Factories which poll the Server's for screenshot requests in its queue.

The author of project, Johann C. Rocholl, came up with the idea in November 2004. The service has been around since Feb 2005.

Native (W3C) XMLHttpRequest for IE6 and earlier browsers

With IE7 implementing XMLHttpRequest as a native JavaScript Object, the need to fork JavaScript for XMLHttpRequest is now limited to IE6 and earlier major browsers.

Here is my wrapper for IE6 and lower browsers so you can use the XMLHttpRequest syntax in those browsers also.

/**
* Emulate window.XMLHttpRequest in IE6-
*/
if (!window.XMLHttpRequest) {
 var ms_xhr_ver = false;
 window.XMLHttpRequest = function() {
  if (ms_xhr_ver) return new ActiveXObject(ms_xhr_ver);
  var xhr = false;
  var versions = [
  "Msxml2.XMLHTTP.7.0", 
  "Msxml2.XMLHTTP.6.0", 
  "Msxml2.XMLHTTP.5.0", 
  "Msxml2.XMLHTTP.4.0", 
  "MSXML2.XMLHTTP.3.0", 
  "MSXML2.XMLHTTP",
  "Microsoft.XMLHTTP"];
  var n = versions.length;
  for (var i = 0; i <  n; i++) {
   try {
    if (xhr = new ActiveXObject(versions[i])) {
     ms_xhr_ver = versions[i];
     break;
    }
   } catch (e) { /* try next */ }
  }
  return xhr;
 };
}

Here is some example usage:

/**
* Example usage of native XHR in IE6
*/
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() { 
 if (xhr.readyState == 4) {
  if (xhr.status == 200) {
   alert(xhr.responseText);
  }
 }
};
xhr.open('get', '/2008/02/native-w3c-xmlhttprequest-for-ie6-and.html');
xhr.send('');

Try It

You'll notice that you can use the same syntax in all major browsers, Firefox, IE6, IE7, Safari etc. There is not branching of code once you have emulated native XMLHttpRequest for IE6 and earlier browsers. This can be a good base to either make XMLHttpRequest requests directly, or to build your XMLHttpRequest library.

While I'm on the topic, I'd like to point out a major flaw in some popular XMLHttpRequest libraries. They wrap the ActiveX based XHR of IE6 and earlier before wrapping the native XMLHttpRequest. This will make IE7 use the older version of XMLHttpRequest.

Next I think I'll blog about cross-domain XMLHttpRequest.