FOSSASIA Summit 2017 Singapore – Call for Speakers

The FOSSASIA OpenTechSummit is Asia’s leading Open Technology conference for developers, startups, and IT professionals. In 2017 the event will take place from March 17th – 19th at the Science Centre Singapore.

During three days, thousands of developers, technologists, scientists, entrepreneurs and artists get together to showcase latest technologies, communicate, exchange ideas, learn from each other, and collaborate. Topics range from information technology and Open Source software development to hardware and maker projects, open design tools, machine learning, DevOps, knowledge tools, and citizen science.

For our 2017 feature event we are looking for speaker submissions for the following tracks:

* Open Source Software
* Design, Art & Culture,
* Internet, Society & Politics,
* Hardware & Making,
* Health and Technology
* Science
* Kernel Track and
* Startup and Business Development

Apart from the conference program, the FOSSASIA Summit offers an exhibition space for company and project stands and areas for community assemblies, and developer meetings.

Submission Guidelines

Please propose your session as early as possible and include a description of your session proposal that is as complete as possible. The description is of particular importance for the selection. Once accepted, speakers will receive a code for a speakers ticket. Please indicate on the submissions form if you would like to apply for a sponsored community ticket.

Submission Link:

Dates & deadlines

Please send us your proposal as soon as possible via the FOSSASIA Summit speaker registration.

December 20th, 2016: Deadline for submissions
January 18th, 2017: Notification of acceptance
March 17th – 19th, 2017: FOSSASIA OpenTechSummit

Sessions and Tracks

Talks and Workshops
Talk slots are 20 minutes long plus 5-10 minutes for questions and answers. You can also sign up for either a 1-hour long or a 2-hours workshop. Longer sessions are possible in principle. Please tell us the proposed length of your session at the time of submission.

Lightning talks
You have some interesting ideas but do not want to submit a full talk? We suggest you go for a lightning talk which is a 5 minutes slot to present your idea or project. You are welcome to continue the discussion in break out areas. There are tables and chairs to serve your get-togethers.

Stands and assemblies
We offer spaces in our exhibition area for companies, community projects, installations, workshops, team gatherings and other fun activities. We are curious to know what you would like to make, bring or show. Please add details in the submission form.

Developer Rooms/Track Hosts
Get in touch early if you plan to organize a developer room at the event. FOSSASIA is also looking for team members who are interested to co-host and moderate tracks. Please sign up to become a host here.


Audio and video recordings of the lectures will be published in various formats under the Creative Commons Attribution 4.0 International (CC BY 4.0) license. This license allows commercial use by media institutions as part of their reporting. If you do not wish for material from your lecture to be published or streamed, please let us know in your submission.

Sponsorship & Contact

If you would like to sponsor FOSSASIA or have any questions, please contact us via [email protected]


FOSSASIA Summit 2017:

FOSSASIA Summit 2016 Event: Wrap-Up



FOSSASIA on Twitter:

FOSSASIA Coding Contest:

Adding swap space to your DigitalOcean droplet, if you run out of RAM

The Open Event Android App generator runs on a DigitalOcean. The deployment runs on a USD 10 box, that has 1 GB of RAM, but for testing I often use a USD 5 box, that has only 512mb of RAM.

When trying to build an android app using gradle and Java 8, there could be an issue where you run out of RAM (especially if it’s 512 only).

What we can do to remedy this problem is creating a swapfile. On an SSD based system, Swap spaces work almost as fast as RAM, because SSDs have very high R/W speeds.

Check hard disk space availability using

df -h

There should be an output like this

Filesystem      Size  Used Avail Use% Mounted on
udev            238M     0  238M   0% /dev
tmpfs            49M  624K   49M   2% /run
/dev/vda1        20G  1.1G   18G   6% /
tmpfs           245M     0  245M   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           245M     0  245M   0% /sys/fs/cgroup
tmpfs            49M     0   49M   0% /run/user/1001

The steps to create a swap file and allocating it as swap are

sudo fallocate -l 1G /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile

We can verify using

sudo swapon --show
/swapfile file 1024M   0B   -1

And now if we see RAM usage using free -h , we’ll see

              total        used        free      shared  buff/cache   available
Mem:           488M         37M         96M        652K        354M        425M
Swap:          1.0G          0B        1.0G

Do not use this as a permanent measure for any SSD based filesystem. It can corrupt your SSD if used as swap for long. We use this only for short periods of time to help us build android apks on low ram systems.

Working with ButterKnife in Android


The following tutorial will help you understand Butter Knife implementation in Android

Why to use Butter Knife for Android?

Butter Knife in short is used in case for method binding of Android Views. Butter Knife is mainly used to make coding clean and simple especially in cases where where you deal with complex layout. Usually if you aren’t using Butter Knife you’ll have to eventually use findViewById() method for each view that you create in your layout, in cases where your application deals with many TextView’s, EditText’s, Button’s , ImageView’s the lines of code you write extends. In such cases Butter Knife comes in handy, using which you can reduce many lines of code and simply avoid methods such as findViewById().

Does Butter Knife make your App to slow down ?

No. Butter Knife doesn’t slow down your App, it gives the same result as when you declare your views using findViewById. The reason behind it is ButterKnife automatically generates findViewById calls at compile time itself thus, making use of “Annotation Processing”.

Butter Knife in Action :

Usage in xml :


android:hint="First Name"

Usage in Java class.
LinearLayout linearLayout;
EditText edittext;
//Just use the below code for setting a OnclickListener. That’s it. you don’t need to use findViewById multiple times
void OnLayoutClicked(View view) {
//Do Your Stuff here

Learn more about butterknife at :

Motion in android

So earlier this year I attended a talk where the speaker wanted to introduce us to meaningful motion in android apps and he convinced us to use this in our apps as well. Motion came in with Material design, actually not really came but became popular with Material design and since google has added the same kind of motions to their apps as well, developers have started using it.

I love motion, not only does it boost engagement but it’s instantly noticeable. Think of the apps you use that feature motion design and how pleasing, satisfying, fluent and natural they feel to experience. Eg. Zomato, Play music etc.

Now think of some apps that don’t use any kind of motions and you’ll realise they look a bit boring and you as users will always prefer apps with some kind of motion.


So firstly let’s discover the feedback on touch. It helps to communicate to the user in a visual form that some interaction has been made. But also keep in mind that this animation should be enough for them to gain clarity and encourage further explorations and not distract them.

For adding backgrounds you can use the following :

  • ?android:attr/selectableItemBackground — Show a ripple effect within the bounds of the view.
  • ?android:attr/selectableItemBackgroundBorderless — Show a ripple effect extending the bounds of the view.

View Property Animator

Introduced in API 12, this allows us to perform animated operations (in parallel) on a number of view properties using a single Animator instance

Some of the parameters that can be added to a view are as follows :

  • alpha() -Set the alpha value to be animated to
  • scaleX() & scaleY()— Scales the view on it’s X and / or Y axis
  • translationZ() — Translates the view on its Z axis
  • setDuration()— Sets the duration of the animation
  • setStartDelay() — Sets the delay on the animation
  • setInterpolator() — Sets the animation interpolator
  • setListener() — Set a listener for when the animation starts, ends, repeats or is cancelled.

Now let’s write some code on how to do this on a button for example:

.setInterpolator(new FastOutSlowInInterpolator())        .setStartDelay(200)        
.setListener(new Animator.AnimatorListener() {            
public void onAnimationStart(Animator animation) { }             
public void onAnimationEnd(Animator animation) { }             
public void onAnimationCancel(Animator animation) { }             
public void onAnimationRepeat(Animator animation) { }        

Note : Use ViewCompat class to implement the ViewPropertyAnimator from Android API version 4 and up

Object Animator

Similar to the ViewPropertyAnimator, the ObjectAnimator allows us to perform animations on various properties of the target view (both in code and XML resource files). However, there a couple of differences:

  • The ObjectAnimator only allows animations on a single property per instance e.g.Scale X followed by Scale Y.
  • However, it allows animations on a custom Property e.g. A view’s foreground colour.

Her we need to set the evaluator, set the delay and call start().

private void animateForegroundColor(@ColorInt final int targetColor) {   
    ObjectAnimator animator = ObjectAnimator.ofInt(YOUR_VIEW, FOREGROUND_COLOR, Color.TRANSPARENT, targetColor);                    animator.setEvaluator(new ArgbEvaluator()); animator.setStartDelay(DELAY_COLOR_CHANGE); animator.start();}


An Interpolator can be used to define the rate of change for an animation, meaning the speed, acceleration and behaviour during animating can be altered. Some of them are :

These are some of the basics. there are a lot of other things like

  • Window transitions(Explode, fade, slide etc.)
  • Shared element Transitions
  • Other custom transitions
  • Animated Vector drawables

you can play around with these for a better understanding but be sure to actually try everything on a device/emulator since you’ll get to actually see the changes in the UI and in turn understand better.

Using Partial in Handlebars and Reusing Code

Open Event Webapp uses handlebar partials for optimizing code. We can reuse a template using Handlebars partial.

How to use Handlebars partial ?

To use Handlebars partial, we have to follow some easy steps:

Step 1: In the .hbs file containing code, register your partial by using function Handlebars.registerPartial 

Handlebars.registerPartial('myPartial', '{{name}}')

Step 2: Calling the partial

{{> myPartial }}

In Open-Event Webapp we have made partials for common templates like navbar and footer.

1. // Navbar template (navbar.hbs)

 <!-- Fixed navbar -->
 <nav class="navbar navbar-default navbar-fixed-top">
  <div class="container">
   <div class="navbar-header navbar-left pull-left">
    <a class="navbar-brand" href="{{ eventurls.main_page_url }}">
    {{#if eventurls.logo_url}}
    <img alt="{{}}" class="logo logo-dark" src="{{  eventurls.logo_url }}">
    {{ }}
 <div class="navbar-header navbar-right pull-right">
   <ul style="margin-left:20px" class="nav navbar-nav pull-left">
   {{#if show}}
    <li class="pull-left"><a href="{{link}}" style="padding-right:0; padding-left:0;margin-left:15px"><i class="fa fa-lg fa-{{icon}}" aria-hidden="true" title="{{{icon}}}"></i></a></li>
 <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse" style="margin-left:1em;margin-top:1em;">
   <span class="sr-only">Toggle navigation</span>
   <span class="icon-bar"></span>
   <span class="icon-bar"></span>
   <span class="icon-bar"></span>

 <div class="hidden-lg hidden-md hidden-sm clearfix"></div>
   <div class="collapse navbar-collapse">
    <ul class="nav navbar-nav navbar-right">
     <li class="navlink"><a id="homelink" href="index.html">Home</a>
     {{#if timeList}}
     <li class="navlink">
     <a id="schedulelink"href="schedule.html">
     {{#if tracks}}
     <li class="navlink">
      <a id="trackslink" href="tracks.html">Tracks</a>
     {{#if roomsinfo}}
     <li class="navlink">
      <a id="roomslink" href="rooms.html">Rooms</a>   
    {{#if speakerslist}}
    <li class="navlink">
      <a id="speakerslink" href="speakers.html">Speakers</a>
//Compiling Template by providing path

2. const navbar = handlebars.compile(fs.readFileSync(__dirname + '/templates/partials/navbar.hbs').toString('utf-8'));
// Register Partial

3. handlebars.registerPartial('navbar', navbar);

sTeam GSoC 2016 Windup

(ˢᵒᶜⁱᵉᵗʸserver) aims to be a platform for developing collaborative applications.
sTeam server project repository: sTeam.
sTeam-REST API repository: sTeam-REST

An overview of the work done by ajinkya007 during Google Summer of code 2016 with FOSSASIA on its project sTeam.

The community bonding period saw the creation of a docker image and a debian package for the sTeam server. The integration of the sTeam shell into vi, improvements in the export and import to git scripts, user and group manipulation commands, sending mails through the commandline, viewing logs and the edit script modifications were done subsequently. The later part of GSOC saw that the sTeam-rest repository was restructured, unit and api-end point tests were performed. The new web interface developed was tested.
The code written during this period by me and siddhant was merged and the conflicts were resolved. The merged code was tested thoroughly as no automated test integration tool supports pike programming language. Documentation was generated using Doxygen and deployed in the gh-pages of the sTeam server repository.

A trello board was maintained throughout the course of GSOC 2016.

Trello Board: sTeam


Issues Reported and Resolved

A list of tasks covered and all the Pull requests related to each:

Tasks Issue PR
Make changes in the Makefile for installation of sTeam. Issue-25 Issue-27 PR-66 PR-67
Edit script modifications Issue-20 Issue-29 Issue-43 PR-44 PR-48
Indentation of output in steal-shell. Issue-24 PR-42
Integrate steam-shell into vim or emacs. Issue-37 Issue-43 Issue-49 PR-41 PR-48 PR-51
Improve the import and export from git scripts. Issue-9 Issue-14 Issue-16 Issue-18 Issue-19 Issue-46 PR-45 PR-54 PR-55 PR-76
Create, Delete and List the user through commandline Issue-58 Issue-69 Issue-72 PR-59 PR-70 PR-78
Sending Mails through commandline Issue-74 PR-85
Generate error logs and display them in CLI Issue-83 PR-86
Create a file of any mime type from command line. Issue-79 PR-82
Add more commands for group operations. Issue-80 PR-84
Add more utility to the steam-shell Issue-56 Issue-71 Issue-73 PR-57 PR-75 PR-81
Restructure the sTeam-rest repository List of Issue’s List of PR’s
Write test cases to test sTeam-rest api List of Issue’s List of PR’s
Create a debian package and a docker image for easy deployment Create docker image Docker Image
Document the work done Issue 149 sTeam Server Structure, sTeam Server Documentation
Test the web-interface

Commits Merged

During the course of GSOC 2016, work was done on the sTeam and sTeam-rest repositories.

1. The work done on the sTeam repository.

We have combined all the work into two branches for the ease of creating a debian package. The commits made by me in each branch can be seen here.

2. The work done on the sTeam-rest repository

The push request’s sent for the issue’s are yet to be merged in the main repository. The list of PR’s for the sTeam-rest repository.

sTeam-rest PR’s

The weekly blogs

The blogs summarizing the work done during the week were published on my personal website. These can be found on Weekly Blogs
All the blogs can also be found on the Fossasia blog.
The list in reverse chronological order is as follows.


Scrum reports were posted on the #steam-devel on and sTeam google group. The sTeam trello board also has everyday scrum reports.

Further Improvements

  1. sTeam command line lacks the functionality to read and set the object access permissions. sTeam function analogous to getfacl() to change the sTeam server object permisssions.
  2. sTeam debian package for easy installation of the sTeam server. The debian package is yet to be fully packaged.

Special Thanks

  • I would like to thank my mentors Mario Behling, Hong Phuc Dang, Martin Bahr, Trilok Tourani and my peers for being there to help me and guide me.
  • I would like to thank FOSSASIA, sTeam and Pike Community for giving me this opportunity and guiding me in this endeavour.
  • I would also like to thank Google Summer of Code for this experience.

Feel free to explore the repository. Suggestions for improvements are welcomed.

Checkout the FOSSASIA Idea’s page for more information on projects supported by FOSSASIA.

PIL to convert type and quality of image

Image upload is an important part of the server. The images can be in different formats and after applying certain javascript modifications, they can be changed to different formats. For example, when an image is uploaded after cropping in open event organizer server, it is saved in PNG format. But PNG is more than 5 times larger than JPEG image. So when we upload a 150KB image, the image finally reaching the server is around 1MB which is huge. So we need to decide in the server which image format to select in different cases and how to convert them.

Continue reading PIL to convert type and quality of image

Templating with Handlebars and Nodejs

There are many frameworks present today that does DOM manipulation. But, DOM manipulation is useful only with simpler Javascript apps. If we want to deal with huge amount of data, we will need to take the support of templating.

One of the templating libraries is Handlebar.js. Handlebars.js is the lightest and one of the fastest templating libraries I have worked with.

How to work with Handlebars ?

Handlebars can be said as the superset of Mustache templating language. In Open-event-web app, Handlebars is used along with Node.js.

1. To install Handlebars
npm install handlebars
2. To include handlebars
const handlebars = require('handlebars');
const fs         = require('fs-e'xtra);
3. To compile a file ( Extension .tpl or hbs)
const tpl = handlebars.compile(fs.readFileSync(__dirname +   '/templates/schedule.hbs').toString('utf-8'));
fs.writeFileSync(distHelper.distPath + '/' + appFolder + '/tracks.html', tpl(jsonData));

Here jsonData is the JSON Array of objects provided to the template.

An example of a .hbs templating file can be :

 <div class="track-names col-md-2">
 {{# tracks}}
 {{#if title}}
 <ul class="title-inline">
 <li style="background-color:{{{color}}}" class="titlecolor"></li>



KISS Datatable

Recenlty I’ve faced a problem with sorting columns in Datatable.

What is Datatable?

Datatable is a plug-in for Jquery library. It provides a lot of features like pagination, quick search or multi-column ordering. Besides, you can develop easily Bootstrap or Foundation ui css styles. There are also more other option but It doesn’t make sense to list it here, because you can visit their site and you can read clearly documentation. On Datatable website you can see a lot of examples. First of them shows how to improve your ordinary table to awesome and rich of features table. One function changes everything, It’s fantastic!  


Returning to my problem which I’ve faced, as I told it was problem related to sorting column in table.

I know sorting is a trivial thing. I hope that everyone knows it 🙂 Sorting by a date is also implemented in a datatable library. So everything is clear when we don’t change date format to human readable format. I mean something like this ‘3 hours ago’, ‘1 year ago’.

When Open Event team tested how datatable manages ordering columns in that format it didn’t work. It’s quite hard to sort by that format, So I’ve invented an idea. Surely you are wondering what i’ve invented. I’ve postponed my minds about sort by this values. It can direct to overwork. When I thought about it, weird ideas came to my mind, a lots of conditions, If statements… Therefore I’ve resigned from this. I’ve used KISS principle. KISS means ‘keep it simple stupid’. I like it!

Therefore that sorting is implemented on frontend side. I’ve decided not to display human readable date format at the beginning. I find  all dates which have format “YYYY-MM-DD HH:mm” then I replace that format to human readable format. So it’s very quick and comfortable, and doesn’t require a lot conditions to write. Of course I’ve tried to implement it in Datatable library. I suppose that it would  require more effort than it’s now.

Below You can see great function which changes a date in frontend side but does not change data in a datatable. So sorting process takes place in a datatable using format  “YYYY-MM-DD HH:mm” but user see human readable format. Isn’t it awesome?!

function change_column_time_to_humanize_format(datatable_name, column_id) {
  $(datatable_name).each(function( key, value ) {
    $(value).children().each(function( key1, value2 ) {
       if(key1 === column_id ){
          var current_value = $(value2).text().slice(0, 16);
          var changed_value = moment(current_value, "YYYY-MM-DD hh:mm").fromNow()
          var isValid = moment(current_value, "YYYY-MM-DD HH:mm", true).isValid()
          if (changed_value !== current_value && isValid === true){


sTeam Docker Image

(ˢᵒᶜⁱᵉᵗʸserver) aims to be a platform for developing collaborative applications.
sTeam server project repository: sTeam.
sTeam-REST API repository: sTeam-REST


What is Docker?

Docker is open source software to pack, ship and run any application as a lightweight container. Containers are completely hardware and platform independent so you don’t have to worry about whether what you are creating will run everywhere.

In order to facilitate development in all the environments and give the user the ease from the cumbersome installation steps a docker image was made for the sTeam project.
This docker image contains all the necessary dependencies to start the sTeam server.
It also includes the sTeam UI and the Rest API along with it’s dependencies. These have already been installed and developer can start collaborating to it.


The docker image can be found at :

It has all the necessary information for it’s usage and installation.

The dockerfile for the sTeam repository:

FROM ubuntu:latest
RUN apt-get update
RUN apt-get install -y wget git firefox nodejs nodejs-legacy npm
RUN apt-get install -y build-essential mysql-server libmysqld-dev bzip2 libjpeg$
RUN apt-get install -y pike7.8 pike7.8-bzip2 pike7.8-svg
RUN apt-get install -y libxml2-dev libxslt1-dev automake flex
RUN npm install -g npm bower gulp coffee-script jasmine-node frisby
RUN cd home
RUN wget -c$
RUN git clone
RUN cd sTeam
RUN git checkout societyserver-source
RUN ./build
RUN sudo ./install
RUN cd ..
RUN git clone
RUN cd sTeam-web-interface-gsoc-2015
RUN npm install
RUN cd ..
RUN git clone
RUN cd steam-rest
RUN npm install

Feel free to explore the repository. Suggestions for improvements are welcomed.

Checkout the FOSSASIA Idea’s page for more information on projects supported by FOSSASIA.