Angus Blog

Fixing the XPath problem in Firefox 3.6

2010-02-05T10:19:00.009+08:00

In Greasemonkey development, it is a common practice to use GM_xmlhttpRequest + DOM Document Wrapper + XPath to process cross-origin content. However in Firefox 3.6, the XPath query stop working. Here is the fix:

Firefox 3.5 code


var doc = document.implementation.createDocument("", "", null);
div.innerHTML = html;
doc.appendChild(div);
var res = doc.evaluate("//p[@class='content']/span", div, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
// res is null

Firefox 3.6 code


var isFF36up = false;
if (navigator.userAgent) {
  var ffver = navigator.userAgent.match(/Firefox\/3\.(\d+)/);
  isFF36up = ffver && parseInt(ffver[1], 10) >= 6;
}

var nsResolver = {
  lookupNamespaceURI:function (prefix) {
    if (isFF36up && prefix == "ns") {
      return "http://www.w3.org/1999/xhtml";
    }
    else {
      return "";
    }
  }
};

var doc = document.implementation.createDocument("", "", null);
div.innerHTML = html;
doc.appendChild(div);
var res = doc.evaluate("//ns:p[@class='content']/ns:span", div, nsResolver, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;

Better Mobile Twitter version 5

2009-03-19T19:54:00.005+08:00

Just released the version 5 of Better Mobile Twitter greasemonkey script. You can install in http://userscripts.org/scripts/show/35396. There version adds image preview and auto expand short URL.

I prefer to use the mobile web version of Twitter because it is faster. Better Mobile Twitter is to enhance the user experience in Twitter's mobile version, with the following features:

Automatically load next page when scrolling to bottom of the page (continues browsing similar to Google Reader)
Display replies and direct messages in sidebar (New)
Images and Youtube thumbnail preview (supports twitpic, flickr, YouTube, hellotxt, ping.fm, TwinkleShots) (New)
Auto expand short URL (supports Tinyurl, bit.ly, Friendfeed, hellotxt, is.gd, Ping.fm, short.to, SnipURL, Tweetburner, tr.im) (New)
Add reply button like standard version (New)
Count the characters remaining as you typing
Check for new tweets in background and display number of new tweets in title bar
Wider input box
Add a user filter
An on/off button so you can turn off the auto-next-page function to access the links in the bottom of the page

Firefox users can first install the Greasemonkey add-on, install the script from http://userscripts.org/scripts/show/35396, then point your browser to http://m.twitter.com/home.

Chrome users please read this document to enable user scripts.

You can take a look on my other greasemonkey scripts in my user page in userscripts.org.

Better Mobile Twitter version 4

2009-03-03T10:37:00.006+08:00

Just released the version 4 of Better Mobile Twitter greasemonkey script. You can install in http://userscripts.org/scripts/show/35396. There version adds image preview and auto expand short URL.

Better Mobile Twitter is to enhance the user experience in Twitter's mobile version, with the following features:

Automatically load the next page when scrolling to bottom of the page (similar to Google Reader)
Images and Youtube thumbnail preview (supports twitpic, flickr, YouTube and TwinkleShots) (New, Firefox only)
Auto expand short URL (supports Tinyurl, bit.ly, Friendfeed, hellotxt, is.gd, Ping.fm and SnipURL) (New, Firefox only)
Count the characters remaining as you typing
Check for new tweets in background and display number of new tweets in title bar (New)
Wider input box
Add a user filter (New)
An on/off button so you can turn off the auto-next-page function to access the links in the bottom of the page

ESPN FBA Player Rater userscript

2008-12-18T14:36:00.012+08:00

For Fantasy Basketball lover! A small Greasemonkey script that show more information in ESPN FBA Player Rater page:

Positional ranking (PRK)
% owned
Average draft position (ADP)

Not very useful, but is funny for you to locate the sleepers and dusts. Watch Nene jump from ADP 96 to rank 21, Duhon from ADP 122 to 29 and Millsap from undrafted to 31.

Down to the table, you will feel sorry for the owners of Marion (11.5 to 72), Iverson (11.3 to 85) and Brand (17.2 to 111).

Install and download from http://userscripts.org/scripts/show/38843. It supports Firefox and Chrome (Chrome users please read this post).

Chrome 1.0 (not Chromium) supports Greasemonkey now

2008-12-16T13:17:00.010+08:00

Google Chrome 1.0 supports Greasemonkey. You can use Google Reader Unread Count and Better Mobile Twitter in Chrome now.

To enable Greasemonkey in Chrome, download and install the latest Chrome. Right click your Chrome shortcut, add "--enable-greasemonkey" to the end of the "Target" box (see below). Finally, you have to put the scripts in the folder "C:\scripts\" and the script files' extension must be ".user.js".

Google Reader has new look

2008-12-05T09:49:00.002+08:00

Google Reader has new look. I like the collapsible section so I can free more space for the feed list. And I'm please to tell you that my Google Reader Unread Count greasemonkey script still works for new look. Enjoy it.

Better Mobile Twitter version 3

2008-11-20T01:15:00.003+08:00

Just finish the version 3 of Better Mobile Twitter greasemonkey script. You can install in http://userscripts.org/scripts/show/35396.

Better Mobile Twitter is to enhance the user experience in Twitter's mobile version, with the following features:

Automatically load the next page when scrolling to bottom of the page (similar to Google Reader)
Count the characters remaining as you typing
Check for new tweets in background
Wider input box
An on/off button so you can turn off the auto-next-page function to access the links in the bottom of the page

You can see how it works in the video below.

Firefox users can first install the Greasemonkey add-on, install the script from http://userscripts.org/scripts/show/35396, then point your browser to http://m.twitter.com/home.

Chrome users need to download the nightly build of Chromium, put the script in c:\scripts and run Chrome with command-line "chrome.exe --enable-greasemonkey", or create a shortcut for it.

You can take a look on my other greasemonkey scripts in my user page in userscripts.org.

Google Reader Unread Count version 4 supports Chrome

2008-11-14T09:50:00.007+08:00

I rewrite the Google Reader Unread Count user script to support Chrome (i.e. Chromium nightly build). And fix the bug that cannot display the '+' sign if any one single feed has more than 1000 unread items.

Get the update from http://userscripts.org/scripts/show/12601.

There is a major difference of Greasemonkey support in Firefox and Chrome. In Firefox, your user script is put in a separated context. That's why you should use unsafeWindow to refer to the webpage's context. In Chrome, otherwise, is put in same context of the webpage. This introduce name conflicts in the script. For example, I added the famous $(id) function in my script which overrides the original $ function in Google Reader and makes it broken. To solve it I put everything in my own namespace to avoid the conflict.

Google Reader Unread Count version 3

2008-11-07T01:21:00.002+08:00

Someone reported that my Google Reader Unread Count user script doesn't work since 28-Oct (I'm busy keeping my unread items below 1000 so I didn't notice that it is broken). I made up a version 3 to fix this problem and another bug that didn't count the untagged feeds.

Get the update from http://userscripts.org/scripts/show/12601.

In addition, I include this script to my greasemonkey collections project (ellab-gm) in Google Code. Please check out my other scripts.

Better Mobile Twitter user script

2008-10-13T01:38:00.001+08:00

I always keep a tab in Firefox opening Twitter and I prefer the mobile version instead of the standard one for speed and simplicity.

Despite the simplicity, one thing I would like to have is automatically load next page when the mouse scroll to bottom (just like what Google Reader does). As a result I come up with the Better Mobile Twitter user script.

You can install in http://userscripts.org/scripts/show/35396.

Below is showing how it works, or you can watch in high quality.

Some stats from Firefox 3 Download Day

2008-06-14T09:28:00.000+08:00

Did you pledge in Firefox 3 Download Day 2008? For me, I'm very interest on the world map, where I know how many people pledge to download Firefox 3 on the first day in each country or region. To have a more detail view, I wrote an AppJet webapp to visualize the data.

Here is the URL:

http://ffpledge08.appjet.net/

We can see that besides US, Poland has the second most pledges, followed by Brazil, France and Italy.

If we count the population factor, among the regions which population greater than 1 million, Slovenia has the highest support rate - 0.25% of Slovenian promise to download Firefox 3 in the first day of release. Estonia and Poland are not far behind, has 0.23% and 0.22% respectively.

The data by some means reflecting the Internet penetrating rate in these countries. For example, Bangladesh and Nigeria, which population greater than 100 million, have only 500 and 200 pledges respectively. Most Africa countries fill up the bottoms. Ethiopia is the worst, only 70 out of 77,127,000 people pledged.

The best About Us I ever seen

2008-01-16T04:12:00.000+08:00

Zavity may not be a success web2.0 startup, but it's About Us is the best I ever seen.

See TechCrunch's article about Zavity.

My first AppJet and some thoughts on it

2007-12-19T16:46:00.000+08:00

I write my first AppJet application, which is migrate from a Google Gadget. The migration is smooth and the experience is very good. The app is called "Goal Chart" you can try it from the following URL.

http://goalchart.appjet.net/

AppJet is great for writing small-scale web application. If it provides a XML+HTML parser and support OpenID it will be our dream platform for writing mashup.

Howto install Firefox 3 co-exists with Firefox 2

2007-11-24T02:33:00.001+08:00

Mozilla just release Firefox 3 Beta 1. Review said it is much faster and consume less memory. It definitely worth a try but for the obvious reason you have to keep your Firefox 2. Here is the steps show you how to install Firefox 3 and make it co-exists with Firefox 2.

1. Right click the shortcut of the Firefox 2, click "Properties". Add "-profilemanager" at the end of the shortcut path. Click OK. Then run this shortcut to launch Firefox Profile Manager.

2. Create a new profile, name it "firefox3". And uncheck the "Don't ask at startup"

3. Go to Properties of the Firefox 2 shortcut again, remove the "-profilemanager" and add "-p default" at the end of the path. This forces Firefox 2 to open the original profile.

4. Start install Firefox 3. Choose "Custom" when you are asked.

5. The default Destination Folder is "Mozilla Firefox 3 Beta 1", which is stupid when you later update to Beta 2, Beta 3 or even 3.0.1. So change it to Mozilla Firefox 3

6. Same in Start Menu Folder name.

7. When installation completed, uncheck the "Launch Firefox now". You still have something to do before you can run it.

8. Go to the Properties of the Firefox 3 shortcut. Append "-no-remote -p firefox3" to the Target. The "-no-remote" will let Firefox run a separate instance. The "-p firefox3" will force yoru Firefox 3 to run the newly clean profile.

9. Run the Firefox 3, and you will be prompted that your Firefox is not the default browser. DON'T click Yes. Firefox 3 is not stable and you won't like to use it as your default browser. Simple uncheck the "Always perform this check when starting Firefox" and click No.

10. Now you can run Firefox 2 and Firefox 3 at the same time. Enjoy it.

The most overrated Firefox addons

2007-11-10T02:37:00.000+08:00

I like Firefox, and addons is the biggest reason. But some of highly rated addons doesn't seems to be that useful and you shouldn't install them. Here is my brief review of the top 10 Firefox addons (as of 9-Nov-2007).

3. NoScript by Giorgio Maone

"Winner of the "2006 PC World World Class Award", this tool makes Firefox the safest browser around."

If you want the safest browser, get lynx. Without javascript you have problem visiting all of your favorite website, including Gmail, Facebook and Meebo. Once installed it, you find yourself just keep allowing javascript for each site you visit, which is very annoying

Firefox is safe, period.

6. PDF Download by Denis Remondini

"Allows to choose if you want to view a PDF file inside the browser (as PDF or HTML), if you want to view it outside Firefox with your default or custom PDF reader, or if you want to download it!"

If you want to view PDF outside Firefox, use Foxit Reader.

9. Forecastfox by richwklein, Jon Stritar

"Get international weather forecasts from AccuWeather.com, and display it in any toolbar or statusbar with this highly customizable and unobtrusive.."

Believe me, you don't need to know the weather every second. When you want to know, just click the bookmark.

10. FoxyTunes by Alex Sirota

"Do you listen to Music while surfing the Web? FoxyTunes lets you control almost any media player and find lyrics, covers, videos, bios and much more with a click right from your browser."

Just because I like to control my player directly instead of clicking the tiny buttons in my browser.

Greasemonkey script to show actual unread count in Google Reader

2007-09-29T03:15:00.001+08:00

I subscribed over 200 feeds in Google Reader. And for some reason I did not login for a week, guess what? I have thousands of unread items. At the old days, Google Reader displayed "100+" unread items which is absolutely not enough for most users. After upgrading, it improved. Now it displays "1000+" as unread items count. It is enough for most cases, but not this one.

I start clearing the articles. After a few hours I loss the motivation. The unread count is always "1000+" and I don't know when can I finish. I don't know the target. I need to know the exact unread items count. So I wrote a Greasemonkey script to calculate the actual unread count.

Install the script in userscripts.org

After installed the script, you can see a button (the Google Reader icon) besides the unread count, click on it will do the calculation and update the unread count with the actual number. Note that it will ignore any duplicated entries.

This is not the best solution. It doesn't auto-update, you have to click it every time. But at least you can get the count and you shouldn't use it every day.

7-Nov-2008 update:
Version 3 released to fix the layout changed from Google. Details here.

13-Nov-2008 update:

Version 4 released to support Chrome. Details here.

Preserve directory when change drive in cygwin

2007-02-07T03:58:00.000+08:00

In cygwin, you can use "cd c:" or "cd d:" to change to different drives. However, it always change to the root directory of the drive. In Windows command prompt you have a nice feature that the c: or d: will change to the directory that you previous stayed in that drive. For example:

C:\Program Files\Mozilla Firefox\extensions>d:
D:\>c:
C:\Program Files\Mozilla Firefox\extensions>

However, in bash, you just can't do this

extensions>cd d:
d>cd c:
c>

Here I add some aliases to implement this feature in bash. Add the following lines in $HOME/.bashrc:

export PWD_c=c:/
export PWD_d=d:/
export PWD_e=e:/
alias c:='export PWD_`expr substr "$PWD" 11 1`="$PWD";cd "$PWD_c"'
alias d:='export PWD_`expr substr "$PWD" 11 1`="$PWD";cd "$PWD_d"'
alias e:='export PWD_`expr substr "$PWD" 11 1`="$PWD";cd "$PWD_e"'

You may need to add more PWD_x environment variables and alias in case you have more drive. Make sure you have the quotes (") because of the spaces in long file name.