Saturday, August 16, 2008

Productive keyboard shortcuts for Eclipse Editors

I've seen very few developers using true power of Eclipse editors, so I thought of listing few very handy shortcuts that can significantly improve your source editing and navigation speed with Eclipse.

1. Ctrl + J / Ctrl + Shift + J : Inline search, meaning you can type on the fly to search text in current editor. You can use Up/Down arrow keys to navigate between matching text fragment in forward/reverse direction. This is one of the most powerful features you will find in advanced editors like Vim or Emacs.

2. Ctrl + K/ Ctrl + Shift + K : Search text in forward or reverse direction.

3. Ctrl + L : Go to line.

4. Ctrl + Alt + Up/Down : Duplicate current line above/below. Very useful in repeatative assignment statements (Java code, eh?).

5. Alt + Up/Down : Move current line up or down. Also, very handy to select current line.

6. Ctrl + . OR , : This is contextual and may be specific to Java editors: if you have error or warnings in current file in editor it will navigate to them.

All of these except for no. 6 are generic text editor features which are inherited by all eclipse text editors. You will realize that you will work much faster than average user if you start using these key bindings.

Wednesday, August 06, 2008

Synchronizing client requests using Ajax

Before few months I was dealing with a problem where I needed to synchronize the server call sequence on browser. The problem was something like this: Client code will open new window navigating to a different page, but that should happen only after post on current page. The link that new window was opening needed to be server synchronized because of database updates etc. on server.

Being ignorant java-script developer I went ahead and put '' in onsubmit event of submit button, hoping it will be executed before form is submitted; Apparently, it failed. The event handling/dispatching/capturing in java-script is in sad state - it's specific to browser and I must make it work for IE so the pain is obvious. To reveal some more ignorance, I thought of putting '' in onmousedown event assuming form will not be submitted till the code in onmousedown is executed
fully, that too failed. Then, it was clear that '' was essentially a thread fork and will execute in parallel so this event capturing is not going to work here.

Since there was no obvious fix to my problem, I thought of using XMLHTTP for asynchronous wait to synchronize the request. I created new page which will open in a new window with javascript that handles form post in parent window, looks like following:

<body onload="postParentWindow()">
out.print("Loading Print Preview, Please wait...");

getFormValues is a function which concatenates all the input's selected values and makes a request string. More interesting things are done in makePOSTRequest method:
var http_request = false;
function makePOSTRequest(url, parameters) {
http_request = false;
try {
http_request = newActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
http_request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {}
http_request.onreadystatechange = navigateToOtherPage;'POST', url, true);
http_request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
http_request.setRequestHeader("Content-length", parameters.length);
http_request.setRequestHeader("Connection", "close");

function navigateToOtherPage() {
if (http_request.readyState == 4) {
if (http_request.status == 200) {
} else {
alert('There was a problem with the request.');


(Note: This code completely disregards browser compatibility and good error handling etc.) The important thing here is, we can assign a function to XMLHTTP object that will be executed after server response is received so that serves my purpose of synchronizing the request. I find this use of AJAX pretty useful in building stateful web-applications. The code might look very crude but powerful abstractions can be built over it to make a nice utility framework for such use-cases.

Tuesday, August 05, 2008

What's wrong with HP Quality Center?

This entry is rant so you might just want to skip it.

HP Quality Center (formerly Mercury) is a, how so amusingly called, web-based test management tool. You will find a lot of marketing information if you ask Google, most of which is irrelevant and may only have 1-800 number for support; because they know when you are looking for it on web, you are in trouble and no one can help you. Unfortunately, I've to spend a good amount of time on this tool these days and it inspired me a great deal to write my inexpressible ovation for this tool here.

As a programmer, HP Quality center is one of the worst and most annoying tools you may have to work with (some may compare it with Lotus notes though).

This tool is implemented as a giant Active X; Apparently, they didn't want to make it web-based but when sales team threatened their developers, they some how adjusted their extra-thick client to web by (evil) means of Active-X(TM) technology. It only takes one or two more minutes to load than my Eclipse instance does, in Intra-net i.e.. It works only on lame Internet Explorer, in a sense that makes it 70% less web based. To add to the insult of using this tool, you have no option but use god-forsaken IE6 (or 7 if you are slightly lucky).

HP Quality center crashes at will, each crash is designed scientifically so that you waste a few hours to get back to normal work before it crashes again. For example, I add attachment to a defect; next, I go and try to add comment on it and it crashes - right on time. I open new IE window; browse it and wait for it to load, log-in again (this special web based tool doesn't have feature to remember your password in an enterprise-wide SSO environment). After recalling what I was doing last, I go to the defect where it crashed and try to add comment again; only to discover that it still thinks I'm working on it. 'The object is locked by user: [my userid]'. You will praise arcane brilliance imbued in this tool because these problems disappears randomly once it pisses you off - it knows when.

Some more praise on it's resource utilization, so one can't wonder why it is rightfully web-based. HP Quality Center uses ~120mb of your core if you have no defects in your view. This amazing tool can make your wish to see memory usage on crack come true, have 50-40 defects in your view and see the difference.

This is only the tip of the iceberg but gives you bigger picture and idea why companies make more money in support, there's always room for new version, patch, hotfix etc. Why in the world people pay for such crap? there are ton of free alternatives which are hundred times better and are totally free. And the other day someone was complaining about open-source tool usability...