Installing Gentoo Linux across all Pentium 4 machines for DataMill was an easy process. I copied an existing installation across hard drives. While installing Gentoo on the source machine, I had -march=pentium4 in make.conf while I would recommend i686 or x86_64 for a generic install that can be copied over a large number of machines. I follow the same steps as http://www.gentoo-wiki.info/HOWTO_Clone_a_Gentoo_Server_or_Workstation, with slight modifications.

On the source machine, I boot up the System Rescue CD and resize the last partition of the install to fit the hard drive size. I also have netcat compiled and uploaded to my site. I run

to find out its ip address. Before I start the cloning process, I also change the hostname.

On the destination machine, I boot the Gentoo Live CD, download netcat, and listen to port 5000.

Replace the IP address with the one you obtained from the source machine.

I made this video in the summer and Python Fiddle back in 2010. It is still the best Python IDE on the web running in a browser. So here is a demo if you’re new to Python:

First up on the list is the bad news: the old share bar is permanently gone as Google has shut it down. That’s right! Google has shut down a competitor’s service after buying it. At least the meebo team is honest and left us a message:

Meebo was acquired by Google on June 4, 2012.

Our team is now working just a few miles down the road with the Google+ team, where we continue to focus on creating delightful experiences for our users, developers, and publishers.

Meebo’s products are no longer available, but you can find all the latest and greatest things that we’re working on at https://developers.google.com/+/.

Thanks,
The Meebo Team

Elsewhere on the internet, you can find news reports about the shutdown. That gives credence to the “Google is Evil” motto.

On the course explorer side, there has recently been a change to Amazon’s Ecommerce API, breaking code for getting book titles and URLs that I wrote several years ago. Basically, most of the responses returned changed from single item ones to

to multiple item ones

As with many of these bugs, they are easy to fix once cause of the problem is found. If you know XML, an exercise for you is to spot the difference between the top one and the bottom one.

Finally with help and support from my hosting service setting up a newer version of Django to run with a newer version of Python, Building UIs with Wijmo’s official site has been launched. It is just in time for the lucky winners of free copies of the book to join in the party. I spent the last Saturday writing the site and the ideas over the last month just came together.

After launching the a new tips panel on Fiddle Salad that shows on top of other dialog windows whenever a fiddle is opened, I found a decline in traffic. Specifically, page views decreased. Does that mean the tips were poorly done? To investigate, I compared the views in the past 30 days to the previous period and looked at the traffic for different pages. The top pages ranked by page view saw an increase in ratio compared to the rest. My hypothesis is that when opening a saved fiddle, users were deterred by the tip panel that opened. I found the data to back up the hypothesis.

The analysis is that there were 0 visitors to the pages in the past 30 days because they just didn’t bother to check off “Show tips on startup”. This made sense, as the tips panel often blocked pieces of code. My plan is to just show the tips panel once a day so that opening saved fiddles wouldn’t show it.

Update:
I found out that the new tab page in Chrome stable was changed, removing the apps. This would explain the decline in traffic on the CoffeeScript IDE page. This change has been there for 4 months on the Chrome beta channel that I use on Windows.

Right after I finished my classes at Waterloo, I started writing my book on Wijmo. Wijmo is an advanced widget library based on jQuery UI, which is the most popular UI toolkit in the community. The preface to my book explains what the book is about:

Wijmo is a new JavaScript library focusing on user interface widgets. It builds on jQuery UI, enhancing existing widgets, and adding new ones. In this book we examine the Wijmo widgets essential for web development. The useful configuration options for 15 widgets are covered along with their usage scenarios. Most of the chapters take a code recipe approach for tasks that occur often in web development. Whenever you come across a widget or user interface component that you’ve implemented before, chances are that Wijmo widgets have you covered. The chapters in this book are designed to get you started using the widgets in no time. On the other hand, Chapter 6, Dashboard with Wijmo Grid, takes a different approach in building an application and explaining how it works.

I would recommend buying this book if you’ve already purchased a license for Wijmo or you plan to be using Wijmo for development. On my project at work and while writing this book, I have used Wijmo in combination with Knockout to put together UIs.

Building UIs With Wijmo was just published last month. I was originally contacted by the publisher to write the book because I had used Wijmo on one of my Github projects. The best thing is one favourite pet project leads to another. I will save that for another post, but for now there is a contest running on Fiddle Salad if you want a free copy.

On one of the computers I was using, I started noticing a high pitched noise after I moved into a quieter room. At first, I thought I heard it after I turned off the computer. It must have been one of those ghosts. I haven’t bothered with it until today because I rarely turn off my computer. Also, it didn’t have support for suspend compiled into the kernel, which often requires a lot of modules to be built. I am using a minimal kernel seed from http://kernel-seeds.org/, so I didn’t bother adding those modules.
You can tell the high pitched noise is coming from your CPU if running a computationally intensive process suddenly silences it. First, I tried adding more CPU power management and adjusting fan speeds in the BIOS. They are related. If the CPU is using less power and running cooler, the fan also spins slower with less noise. I didn’t expect Intel’s market dominating CPU to be producing the noise. However, just like Windows or any market leader, there’s not enough competition for such things to be a threat. Next, typing a simple search query for “linux kernel config high pitch” lead me to http://www.thinkwiki.org/wiki/Problem_with_high_pitch_noises, and I tried the first solution by recompiling my kernel. I had a similar problem with my old Dell laptop when it went to sleep. I ended up never using sleep so that I could sleep at night.
The solution is to set CONFIG_ACPI_PROCESSOR=n under ACPI options. If you’re new to compiling a kernel, a good guide is Linux Sea.

Angular JS is a popular MVC framework by Google, and I received a bug report that Fiddle Salad wouldn’t reload the preview as it does in all other cases. This problem was noticed before, but it wasn’t a priority since pressing the refresh button as required in all other web development methods solves the problem. However, this was because I was attempting to solve it at the wrong level by modifying a method. As I’ve learned, there are dependencies between the execute, reset, and initiation of the class involved.

Fiddle Salad’s CodeRunner class has just 5 public methods. They are

• execute()
• add_file()
• remove_css()
• reset()
• debug()

as in the class diagram on the wiki at https://github.com/yuguang/fiddlesalad/wiki/2.-Classes. Therefore, any implementation of a CodeRunner just needs to support these 5 methods. The debug method could be refactored into a super class because it would generate the template for the new execute() method.

If I just change the last line, the debug method turns into a reset method.

The rest of the class still needs to be completed, but they are as obvious as appending to an array when adding JS/CSS files.

After installing e17 on Gentoo and a few applications, I noticed that some of the applications in the menu had icons while others did not. The same icons were missing in the IBar and other places. At first, I checked the wiki page on e17, it suggested to install evas_generic_loaders with SVG support. Contrary to what it suggests, evas_generic_loaders does not affect menu icon display it is used for tooltip previews in the file browser.
The way to set is to navigate to Settings -> All -> Look -> Application Theme and open the Icons tab. Once I selected Gnome, all the icons appeared. “Enable icon theme for applications” was already checked by default. If you do not see Gnome icons in the Icons tab, make sure you have installed x11-themes/gnome-icon-theme if you’re using Gentoo.

Fiddle Salad has accumulated many features, but where are they? In keeping with one of its principles, features are hidden until the situation calls for them. One example is the JavaScript errors that are shown on hover over the results window. Recently, I’ve decided showing an unobtrusive tips window is as good as hiding features to reduce UI clutter. So, let’s start with 4 lines of Knockout code.

I start by setting startup to a storage value using store.js. It uses HTML5 local storage with cookies for fallback. Since I want to show the tips panel by default and hideTipsOnStartup would not be set, startup is set to the opposite hideTipsOnStartup. JavaScript’s ! and CoffeeScript’s not casts an expression to a boolean, as required by Knockout’s checked binding.
Next, I add a manual subscription to the observable so that its value is stored each time the checkbox is checked or unchecked.
Finally, the checkbox is bound to tips.startup where tips is a TipsPanel instance.