Hello, reader!

My name is Eugene Lazutkin.

I'm a software developer based in the Dallas-Fort Worth metroplex. Lazutkin.com is my professional blog, which contains short writeups and presentations regarding modern web applications. All articles here are written by myself, unless stated otherwise.

tag: Dojo

Using Dojo Rich Editor with Django's Admin

Many years ago I decided to replace plain text areas in Django’s Admin with rich text editor, so I can edit HTML on my blog using WYSIWYG. Six (yes, 6) years ago I looked around and selected TinyMCE. Over time it turned out that I was forced to upgrade TinyMCE and the link script I had because new browsers continue breaking my rich editor editing. Finally it stopped working again in all modern browsers, and I decided that enough is enough.

Exciting JavaScript Part II

4 Mar, 2010 - 1 minutes
This month I continued my presentation at ClubAJAX. Last time I did a survey of what is available in JavaScript, and concentrated on object-oriented (OOP) and aspect-oriented (AOP) techniques. This time I continued the survey, and talked about functional programming (FP), and domain-specific languages (DSL). And as promised I touched the code generation facilities too. I suggest to read the first part before. Enjoy! Direct link: Exciting JavaScript - Part II.


10 Feb, 2010 - 1 minutes
Today at dojo.connect I did a presentation “RAD CRUD”: rapid development of form-based applications. It continues my other presentation “CRUD with Dojo”, but it is more in depth, targets Dojo developers, and contains some advanced material. Direct link: RAD CRUD. View more presentations from Eugene Lazutkin.

Exciting JavaScript Part I

5 Feb, 2010 - 1 minutes
I was asked to talk about advanced JavaScript techniques at the last monthly meeting of ClubAJAX — monthly get-together of Dallas-area JavaScript programmers. Instead I ended up talking about leveraging cool JavaScript features to implement well-known programming techniques and paradigms: OOP, AOP, FP, and so on. Unfortunately I couldn’t finish in time, so I did a tour of some language features, and talked about OOP and AOP. The rest (I plan to do FP, code generation, and DSL) will be covered later.

Dojo Charting demo: tribute to Highcharts

8 Dec, 2009 - 1 minutes
Wolfram Kriesing asked: Somehow I have the feeling that you can bend dojox’s charting module to look and feel like http://highcharts.com/ — will be for free. Yes, it is relatively simple. To prove a point I wrote a quick-and-dirty demo available here: Tribute to Highcharts. Obviously not everything matches 100%. Go and judge for yourself. Update: related post on dojo-dev mailing list, which explains some details of the demo.

CRUD with Dojo

2 Dec, 2009 - 1 minutes
My presentation at ClubAJAX got off to a rocky start: I was let in the building 40 minutes after I was supposed to start the presentation. Everybody waited patiently. Thank you guys! As promised I publish slides along with relevant links (I had to skip most of planned demos). Here is my presentation on SlideShare: CRUD with Dojo. The original presentation can be seen on Google Docs: CRUD with Dojo.

JavaScript explained

1 Mar, 2009 - 5 minutes
Explaining some dark corners of JavaScript, browsers, or Dojo for the 100th time I realized that I already did it on numerous occasions, and some of my answers are published on public web sites. So I decided to round up the most general ones I posted on StackOverflow and publish links to them here for a future reference. JavaScript This section is for language-specific topics. They can be equally applied in any environment.

Using recursion combinators in JavaScript

In the previous post we explored “array extras” and how they can help us to write concise yet performant and clean code. In this post we take a look at generalizing recursive algorithms with recursion combinators — high-level functions that encapsulate all boilerplate code needed to set up the recursion. These functions were added to dojox.lang.functional and will be officially released with Dojo 1.2. In general the recursion is a form of iterative problem solving in the same category as loops.

AOP aspect of JavaScript with Dojo

Finally: my open source JavaScript project DCL is built on ideas described in this article. Available for node.js and modern browsers, it implements OOP with mixins and AOP at "class" and object level. Read documentation and background articles on www.dcljs.org, clone its code on github.com/uhop/dcl, and follow @dcl_js. If we look at the history of computer programming languages, we can see that practically all new programming methodologies were about one thing: taming complexity.

Dojo 1.1 is out

30 Mar, 2008 - 2 minutes
As you all know by now Dojo 1.1 was released in the wild. You can get a lot of useful links and info from James Burke’s post on Dojo 1.1, but let me tell you why you should be excited: Dojo 1.1 is the first official release, which contains dojox.lang.functional. It was available in the trunk for awhile, but now you can use it without deploying Dojo courtesy of AOL CDN.

Dojo docs: gfx and dnd

15 Mar, 2008 - 1 minutes
I just finished the first cut of the dojo.dnd 1.1 technical documentation. Let me use this post to remind you about the dojox.gfx 1.1 documentation. I hope I satisfied the curiosity of many developers, but the ultimate proof will be the number of simple questions on Dojo Forum. Let’s hope it will go down. And don’t forget that the Dojo Book has a DnD chapter too. Both documents are hosted on Google Docs, and are “live” documents — as soon as I update the document it is updated for you too.

Functional fun in JavaScript with Dojo

Everybody knows that JavaScript is a multi-paradigm language, and it can be used to program functionally. Practically all functional idioms can be used directly: higher-order functions, recursion, closures, and so on. The recent resurgence of Functional Programming (FP) brings functional methodologies in the mainstream. FP fundamentals gave us a lot of powerful idioms: iterative functions, which can replace loops, list processing in general, function manipulations, and many other things, which helps us to keep our code small yet concise, more powerful, and more fun.

Improving performance of Dojo-based web applications

Introduction Web 2.0 brought on us an onslaught of new server-side web frameworks, and made it OK to put some code on the client side as well. Yes, I am talking about Ajax. While elements of Ajax were available (and used) for a long time now, 2005 was the crucial year for this relatively old technology fueled by proliferation of modern browsers with proper support of JavaScript and HTML DOM, which, in turn, gave a rise to numerous Ajax toolkits.

Setting up tools 2

This is the 2nd part of Setting up tools on Windows — notes mostly for myself. (No, I don’t run Django with MSSQL under IronPython. Yet.) In this installment I add more stuff to Eclipse, and set up my apps under FastCGI on Linux-based shared host (I use DreamHost). Eclipse This section was updated on 9/30/2006. I already set it up with PyDev and Subclipse. Now I want to add HTML/CSS editing.

Google Summer of Code 2006

2 May, 2006 - 2 minutes
Yes, another Google SoC is upon us. I signed up as a mentor with Dojo and Django. Both projects are on the leading edge of new wave of web-based applications doing extremely cool stuff. I anticipate that some smart students will bridge both projects, but individual projects are fine too. What is Google SoC? Read the FAQ. Who can apply? Any student anywhere in the world can apply. You don’t have to be Comp.

OpenWrt GUI: new release

15 Feb, 2006 - 1 minutes
It looks like this is the last update before upcoming beta release. Besides some minor bug fixes, it sports improved firewall configuration widget: Compact representation of port ranges. Example: tcp 9000-9100 ⇒ mycomp Port redirection. Example: tcp 8080 ⇒ mycomp:80 While the former improves on existing functionality, the latter implements totally new feature. It allows mapping external ports to different ports of internal computers.

Packaging web apps

2 Feb, 2006 - 4 minutes
Have you been frustrated lately by speed of web applications? Typically they have a lot of art, and structured into a nice set of JavaScript and CSS files. They look beautiful, aren’t they? But do you have the patience to wait them load? And proceed from step to step? Of course, it is possible to prepare a web application to high-demand life: merge all stylesheets, and JavaScript files, and compress the result, structure your GUI in such a way that it is possible to combine all small images in one, and so on.

Django Dojo

28 Jan, 2006 - 2 minutes
Django-Dojo alliance was finally announced to the world by our very own Jacob Kaplan-Moss: Starting with version 0.92 (which should be out in a few weeks, Murphy willing), Django is going to bundle Dojo with the toolkit. Specifically as part of Django’s admin interface (but available to user apps as well). Read all about it in Jacob’s post. I am overjoyed to see such cool high quality open source projects are working together.

OpenWrt QoS

27 Jan, 2006 - 1 minutes
It looks like nbd was able to find the problem, which plagued many people (including me) with QoS. You can find details in this thread on OpenWrt forum. Instructions on how to install QoS package can be found in this FAQ entry. Give it a whirl and don’t forget to thank Felix Fietkau (nbd). QoS was the biggest feature on my "wanted" list. It means now I can produce an OpenWrt GUI (webui) module to deal with it.

Live Filtering

Update on 11/25/2007: today this article presents mostly historical interest. Since Dojo 0.2 a lot of versions were published and many things were changed. At the time of this writing Dojo is at ripe 1.0. I had to disable all Ajax action in examples because I don’t use Dojo 0.2 anymore. What is Filtering? It is a selection of items using some criteria (filter). In this tutorial I am going to filter documents of my blog (made with Django, of course) matching titles against user-specified substring.

DIY and NIH syndromes

16 Dec, 2005 - 3 minutes
Many programmers have DIY attitude. It is understandable: they want to do new exciting stuff themselves. In some cases it is perfectly reasonable: exotic functionality, special requirements, performance enhancements, and so on. Sometimes incorporating 3rd-party library makes overall API inconsistent, which is bad especially for programming tools, or big projects. There is a fine line between DIY and NIH, when DIY part is used without rational explanations. Of course, in some cases NIH is reasonable too, e.

Django Ajax Redux

10 Dec, 2005 - 9 minutes
Three weeks ago we had a discussion about Ajax support in Django, which resulted in "Ajax and Django" wiki page. A short recap: it lists a vague goal, some general considerations, and possible strategies; it scratches the surface of existing implementations (mostly RoR), existing third-party toolkits (Mochikit/Dojo), and related RPC-style and REST-style services. No code was produced, no consensus was reached, but now it is a part of Django’s Version One roadmap.

OpenWrt GUI: alpha released!

27 Nov, 2005 - 1 minutes
Finally I released WebUI 0.1 (Homunculus) alpha — AJAX-based web interface for OpenWrt made with Dojo! Highlights of this release: 5 more applets including firewall configurator and more network settings. Now proceed to install the package and to read release notes. The package is here: webui-0.1-alpha.ipk. You can install it using following command in OpenWrt shell: ipkg install http://lazutkin.com/download/webui-0.1-alpha.ipk Release notes: WebUI can be installed side-by side with webif (comes standard with OpenWrt White Russian RC4).

OpenWrt GUI: hosts editor

30 Oct, 2005 - 1 minutes
I didn’t have a lot of time this weekend. So I decided to implement the simplest part of upcoming OpenWrt GUI (webui) — hosts editor. It is a perfect candidate to write something in 15 minutes or less — it has almost no "business" logic in it: read/edit/verify/write cycle. The hardest part was to learn how to upload dynamically generated files without writing them to disk first. It turned out to be very simple.

OpenWrt GUI: preview is released

26 Oct, 2005 - 2 minutes
Update: this document is officially obsolete — alpha is released! Finally I released a preview: /webui-0.1-pre-alpha.ipk! I included two information applets and a simple network configuration applet. I think it would be enough for a proof of concept. I borrowed heavily from nbd’s webif. So if it works for you, it is due to his OpenWrt expertise. If it doesn’t, it is my fault. Both webif and webui can be installed side by side:

OpenWrt GUI: preview is ready, packaging

24 Oct, 2005 - 1 minutes
Finally I found time to finish it up. It is pre-alpha quality now, but shows the direction. The only problem is a packaging. I didn’t mean OpenWrt’s IPKG. I am talking about creating a custom build of Dojo to reduce the foot print. Dojo has a special provision for that but so far I was not able to do it getting some strange errors. I hope I’ll get some help from developers.

OpenWrt GUI: development

30 Sep, 2005 - 1 minutes
I was able to spend several hours this week to work on upcoming OpenWrt GUI. I use Dojo as a foundation. At this point I coded a skeleton, which works as a proof of concept. As soon as I finish putting in AJAX guts, I’ll switch to meaty functionality. Add some nice skin to it and we have our homunculus up and running. Huh? AJAX? No, it’s not Ajax the detergent.

OpenWrt GUI

23 Sep, 2005 - 1 minutes
Finally I bit the bullet and decided to implement OpenWrt web-based user interface using Felix Fietkau’s code. Well, MIPS processors used by OpenWrt units are not race horses and GUI is slow to my taste. Yes, I know that stock firmware is not faster. "Slow" is absolute category for me. How do we combat latencies and slow network speed? Exactly. We can apply the same for OpenWrt, where "slow network speed" is replaced with "slow processor on local network".

Opera and Dojo

5 Sep, 2005 - 1 minutes
I decided to try how well Opera works with my site. It mostly works. You can go and see stuff but all Dojo-related code doesn’t work. Interesting that Google Maps works properly. When I switched to admin mode to edit this article, it turned out that TinyMCE doesn’t work either. But good news is Dojo and TinyMCE failed gracefully.

Dojo: 1st impression

3 Sep, 2005 - 2 minutes
The best thing about Dojo 0.1: it’s quite easy to create portable widgets. Such widgets work similar to Microsoft IE’s behaviors but they are even more self-contained. Dojo widgets can work with fragments of HTML and CSS, which will be inserted during the object creation. The event system is very elaborate. Of course Dojo is more than a simple widget factory. For example I didn’t try the I/O facility yet.

New Design 0.1 is here!

New design is here. Well, some elements of it. I had bigger ideas, but CSS didn’t work reliably, and JavaScript option was in debugging mode. So I decided to update this site now and add other planned stuff later. One reason I postponed JavaScript thingy is I want to try Dojo. It looks like a good foundation for widgets. I am going to create a couple of them at least. If it works okay, I’ll be using it in other projects as well.