searchQuick Apprise: SEVEN #GoogleSummerOfCode #FOSSASIA


The intended searchQuick” (sQuick) is an application to enable a user to search a set of books or texts, like an encyclopedia, or some other topical book collection offline built in the open source platform Pharo 4.0.


After the chief tasks of search functionality and automated build were done with, the next undertaking included working on finer details and embellishments.

  • Embedding Jenkins automated build status icon in GitHub markdown file
  • Relative widget re-sizing by using ‘World extent x‘ and ‘World extent y‘ co-ordinates instead of hard coded co-ordinates
  • Modifying the Accordion Widget by addition of ‘Search Bar‘ at the top
  • Checking for duplicates in the ‘Browse Files‘ menu, thus reducing the CPU consumption
  • Equalizing the sizes of all the windows to bring uniformity
  • Addition of ‘Scroll Pane‘ in accordion search result display list
  • Multi-line search result display by extending the Expander Title Morph and use of new line character in labels (otherwise not supported by default)
  • Truncating file content to first n characters for neater look in Expander Title

Latest Screenshot of Accordion Widget:
Screenshot from 2015-08-18 18:38:06

  • Removal of OK & CANCEL buttons (present by default in Pluggable Dialog Window) from Accordion Widget
  • Implementing of Search via the result window as well
  • Relative re-sizing of background images (Image Morphs)

Continue Reading searchQuick Apprise: SEVEN #GoogleSummerOfCode #FOSSASIA

Knitapps at the 7th Central American Free Software Congress ECSL 2015

On August, 9th, in San Pedro Sula, Honduras, I presented at the seventh Central American Free Software Congress a talk on Knitting Machines, Knitapps, Free Software and Free Manufacture.


I had the opportunity to present on the main auditorium of Unitec, a private, technical university. The audience of the congress was compromised mostly of professionals and students from Central America. Local and National media also covered the event.

Continue Reading Knitapps at the 7th Central American Free Software Congress ECSL 2015

Exception handler in KnitLib

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An exception is an error that happens during the execution of a program. It is important to have exception handler in KnitLib to handle and deal with errors automatically. Many standard libraries define their own exceptions to report errors that may occur in functions they define.  Depending on the kind of error in knitlib (“communication error”, “pattern not found error”, etc.. ). The exception handler module in the knitlib can handle the exception and the knitlib can be continued afterwards with the previously saved data.

Define exceptions as classes

Exception can be defined as classes which do any other class can do, but are usually kept simple, often only offering a number of attributes that allow information about the error to be extracted by handlers for the exception. When creating a library like KnitLib which can raise several distinct errors, a common practice is to create a base class for exceptions and subclass that to create specific exception classes for different error conditions.

Part of the Exception Handler Module, catch exceptions raise from the library
Continue Reading Exception handler in KnitLib

searchQuick Apprise: SIX #GoogleSummerOfCode #FOSSASIA


The intended searchQuick” (sQuick) is an application to enable a user to search a set of books or texts, like an encyclopedia, or some other topical book collection offline built in the open source platform Pharo 4.0.


The main task achieved was putting up the application up on Continuous Integration, Inria for automated build. It was indeed a beneficial idea as it helped me keep a check on the builds and work on issues.
Being a newbie, this work was cumbersome initially but with the help of my mentors and the #pharo community, I was able to accomplish it. To assist fellow Pharo-ers, I have compiled all the information regarding CI Automated Build for yout Pharo Application and published the same on my blog-spot. Kindly go through it for a complete understanding 🙂

Other tasks completed as of now include:

  • Putting up the project for automated build on
  • Successful ‘stable’ and ‘development’ version builds
  • Accessing resource folder via MCGitHubRepository, Removal of manual download option
  • By default full screen system window open
  • Removing redundant code by creating open argument methods
  • Abolishment of hard-coded font family and font point size
  • Categorization of methods & classes
  • GUI Embellishment with background colors, borders etc.


  • Dynamic widget re-sizing
  • Multi-line search result title
  • Putting up Help and About sections
  • Removal of old configurations

Continue Reading searchQuick Apprise: SIX #GoogleSummerOfCode #FOSSASIA

Importance of the test cases for the KnitLib

Having test cases is very important especially for a library like KnitLib because using test cases; we can clearly test particular fields.  In KnitLib, test cases show the information of how the KnitLib should be checked. Also test cases help for new contributors to understand about the KnitLib.

There are several test cases for the current KnitLib implementation such as tests on ayab communication, tests on ayab image, tests on command line interface, tests on KnitPat module and tests on knitting plugin.

For an example in ayab communication there are several important functions have been tested. Test on closing serial port communication, test on opening serial port with a baud rate of 115200 which ayab fits, tests on sending start message to the controller, tests on sending line of data via serial port and tests on reading line from serial communication.  Most of these tests have been done using mock tests. Mock is a python library to test in python.  Using mocks we can replace parts of our system with mock objects and have assertions about how they have been used. We can easily represent some complex objects without having to manually set up stubs as mock objects during a test.

It is very important to improve further test cases on the KnitLib because with the help of good test cases we can guarantee that the KnitLib’s features and functionalities should be working great.



Continue Reading Importance of the test cases for the KnitLib

searchQuick Apprise: FIVE #GoogleSummerOfCode #FOSSASIA


The intended searchQuick” (sQuick) is an application to enable a user to search a set of books or texts, like an encyclopedia, or some other topical book collection offline built in the open source platform Pharo 4.0.


As the rudimentary structure of the application is sewn up, embellishment of GUI and rigorous testing are the major part of course of action.
On eMBee’s ( +Martin Bähr ) suggestion to build up an accordion widget to display the search results, various trials were conducted to design a similar one in Pharo.

The task of developing the accordion widget in Pharo was achieved using Expander Morphs. Looping through the search results array, a #newExpander: was added in each #newRow: of the modal built.

A challenging chore was to add a scroll-able content on the click of the desired search result expander. Sundry experiments with #newLabel: and #newText: in #newScrollPaneFor: {i.e. adding text model and labels in scroll pane} had no effect. Eventually, #newTextEditorFor: did the trick and the desired look was created.
Next on the cards is putting up sQuick for automated build on the CI Server, as suggested by +Sean DeNigris for its various advantages which include:
  • Improvement of product quality
  • Acceleration of compile and link processing
  • Elimination of redundant tasks
  • Minimization of ‘bad builds’
  • Have history of builds and releases in order to investigate issues
  • Save time and money – because of above listed reasons.
For simplicity, Build automation is the act of scripting or automating a wide variety of tasks that software developers do in their day-to-day activities including things like:
  • compiling computer source code into binary code
  • packaging binary code
  • running automated tests
  • deploying to production systems
  • creating documentation and/or release notes
To achieve Build Automation for sQuick, I have already registered on CI and configured sQuick.
Next endeavor is to look into the red signal in the build evaluation.

Stay tuned for more….Post any queries, will be happy to help 🙂
Continue Reading searchQuick Apprise: FIVE #GoogleSummerOfCode #FOSSASIA

More about sTeam’s command line interface

This post will take you through some interesting work that I have been doing for my project under FOSSASIA. This project is being done under the google summer of code platform. I have been working on various code scripts as my project is all about improving the tools of the sTeam collaboration platform. But this particular script is a command line interface that I am thrilled to work on.

If you are not familiar with what sTeam is, you can look it up here, sTeam

Let me start with how sTeam originally works for any user. This picture will give you a clear view about it.


If you are new to the sTeam platform, this script will take you through the sTeam commands and the interface, also making sure, you have fun in the process. It lets the user play with sTeam and get to know more about how it works. One other interesting concept that we have tried to integrate here is that of MUDs(Multi user dungeons/dimensions). Some of you may already be familiar with the concept of MUDs( others, please look it up here MUD). We have tried to bring the MUD kind of experience to this sTeam interface (like I said, thrilling!).

I have seen people go through a lot of tutorials on git, and the commands(sometimes complex) through which it operates, and yet, people have difficulty learning it. What if it had a MUD type of interaction, which would just let you type “create file” “commit file” “get commit content” “upload file” “rename file” “goto repo”, etc. Wouldnt it be much easier that way? Well, sTeam is going through all the extensive tool development so that it can make a user-friendly interaction. Here are some screenshots of this interface,






This interface is under heavy development and plans to make sTeam more and more interesting for its users. If you have any questions on sTeam, please feel free to contact me, or join us on our daily scrum meetings on IRC (#steam-devel) or join #fossasia and ping us with a question.

If you are looking for a open source project and want to contribute to FOSSASIA, Please have a look at FOSSASIA labs.

Continue Reading More about sTeam’s command line interface

Dockerizing sTeam

I am currently working with sTeam collaboration platform as a GSoC dev under FOSSASIA umbrella.

sTeam has a lot of depencencies. A lot! One major issue faced by developers was version conflict between dependencies. Docker seemed to solve this issue. Docker is a great image distribution model for server templates. It uses btrfs (a copy-on-write filesystem) to keep track of filesystem diff’s which can be committed and collaborated on with other users (like git). It also has a central repository of disk images that allow you to easily run different operating systems and shares the host kernel.

In this post, I will explain the workflow of containerizing sTeam with Docker.

Prepend sudo

  • Install docker on host system, start & enable the docker.service
dnf install docker
systemctl start docker
systemctl enable docker
  • Pull a base image from docker hub

Note: It is upto you which image to use. I am using Ubuntu as base image.

docker pull ubuntu:latest
  • List the images to verify the pull
docker images

.. should display ubuntu latest xxxxxxxxxxxx x months ago x MB

  • Build your own image
docker build -t="dolftax/steam"
  • Lets run bash to install sTeam itself and its dependencies
docker run -t -i dolftax/steam /bin/bash
  • Install the packages and its dependencies.

In my case, sTeam server. Installation steps –

  • Grab latest container ID. The first one would be the recently closed container.
docker ps -a
docker commit [container-id] dolftax/steam:v1

You should get a long hash as the success message

Note: v1 is a tag Don’t use latest tag. Don’t be tempted by it.
  • Create a docker hub account and login
docker login

.. which is self explanatory.

  • Push the image to docker hub (Before that, create a docker hub account anddocker login)
docker push dolftax/steam


.. after containerizing with docker, sTeam installation is as easy as

docker pull dolftax/steam:v1

Try containerizing your project and you would love it.

Continue Reading Dockerizing sTeam

Intriguing Read (Bootstrapping Reflective Systems: The Case of Pharo)

Hiya Fellas 😀

So, while I was browsing through various developments in Pharo, I came across a very eye-catching paper on Bootstrapping Reflective Systems: The case of Pharo .

For beginners, Bootstrapping is basically the process of writing a compiler or an assembler in the source programming language in which it is intended to compile. Applying this technique leads to self-hosting compiler that proceeds without external input.

Though, I am still a newbie and in the process of grasping all this ingenious stuff.
But I am sure that this paper ( Poli12-BootstrappingSmalltalk-SCP ) by G. Polito , S. Ducasse , L. Fabresse , N. Bouraqadi , B. van Ryseghem would make for an interesting read.

Do scan through it and post below your ideas and queries !

Continue Reading Intriguing Read (Bootstrapping Reflective Systems: The Case of Pharo)

How to implement JSONP to download XML resource

According to the same-origin security policy, web page can freely share images, stylesheets, scripts… but web fonts and AJAX requests are only accessible from the same domain.

Sometimes this is not desired behaviour, such as when getting a json / xml file from a different domain, using AJAX. In such cases, it all comes down to two solutions :

1- The source sets its header to allow specific domain cross-origin resource sharing (CORS). In PHP, this is done with header function :

header('Access-Control-Allow-Origin: *');

2- Use JSONP.

JSONP is short for JSON padding, a well-known “workaround” to solve CORS. It only works with GET.

To send AJAX requests using JSONP, the server must first knows how to respond to JSONP requests. It usually detects JSONP requests using callback parameter.

// compute result

// output result

// json helper class - credits : @andibraeu
class JsonpHelper {
	private static function is_valid_callback($subject)
	      = '/^[$_\p{L}][$_\p{L}\p{Mn}\p{Mc}\p{Nd}\p{Pc}\x{200C}\x{200D}]*+$/u';
	    $reserved_words = array('break', 'do', 'instanceof', 'typeof', 'case',
	      'else', 'new', 'var', 'catch', 'finally', 'return', 'void', 'continue', 
	      'for', 'switch', 'while', 'debugger', 'function', 'this', 'with', 
	      'default', 'if', 'throw', 'delete', 'in', 'try', 'class', 'enum', 
	      'extends', 'super', 'const', 'export', 'import', 'implements', 'let', 
	      'private', 'public', 'yield', 'interface', 'package', 'protected', 
	      'static', 'null', 'true', 'false');
	    return preg_match($identifier_syntax, $subject)
	        && ! in_array(mb_strtolower($subject, 'UTF-8'), $reserved_words);

	public static function outputXML($string) {
		# JSON if no callback
		if( ! isset($_GET['callback']) )
		$string = str_replace("\n", " ", str_replace("'", '"', $string));
		# JSONP if valid callback
		# Otherwise, bad request
		header('status: 400 Bad Request', true, 400);

Line 29 is dedicated to replace all single-quote characters to double-quote, and new lines to simple space. This is to be able to pass xml document as valid javasript string parameter.

Then, the client can use jQuery to get the document from a different domain (it works on same domain as well, which is convenient for testing & development) :

	url : source_url,
	dataType : 'jsonp',  // if dataType is set to 'jsonp' 
			    // a 'callback' parameter will be appended to the request url
	success: function(data) {
		$data = $($.parseXML(data));
		items = $data.find('item');

Something worth noticing on the client side is on line 5 : the data needs to be converted to xml first, with $.parseXMLbefore converting to jQuery object. Converting the result string directly to jQuery won’t work : $data = $(data);.

That’s about it ! To know more about JSONP, please refer to its wiki

References :

Continue Reading How to implement JSONP to download XML resource