Adding Tweet Streaming Feature in World Mood Tracker loklak App

The World Mood Tracker was added to loklak apps with the feature to display aggregated data from the emotion classifier of loklak server. The next step in the app was adding the feature to display the stream of Tweets from a country as they are discovered by loklak. With the addition of stream servlet in loklak, it was possible to utilise it in this app.

In this blog post, I will be discussing the steps taken while adding to introduce this feature in World Mood Tracker app.

Props for WorldMap component

The WorldMap component holds the view for the map displayed in the app. This is where API calls to classifier endpoint are made and results are displayed on the map. In order to display tweets on clicking a country, we need to define react props so that methods from higher level components can be called.

In order to enable props, we need to change the constructor for the component –

export default class WorldMap extends React.Component {
    constructor(props) {


We can now pass the method from parent component to enable streaming and other components can close the stream by using props in them –

export default class WorldMoodTracker extends React.Component {
    showStream(countryName, countryCode) {
        /* Do something to enable streaming component */
    render() {
        return (
                <WorldMap showStream={this.showStream}/>


Defining Actions on Clicking Country Map

As mentioned in an earlier blog post, World Mood Tracker uses Datamaps to visualize data on a map. In order to trigger a piece of code on clicking a country, we can use the “done” method of the Datamaps instance. This is where we use the props passed earlier –

done: function(datamap) {
    datamap.svg.selectAll('.datamaps-subunit').on('click', function (geography) {
        props.showStream(, reverseCountryCode(;


The name and ID for the country will be used to display name and make API call to stream endpoint respectively.

The StreamOverlay Component

The StreamOverlay components hold all the utilities to display the stream of Tweets from loklak. This component is used from its parent components whose state holds info about displaying this component –

export default class WorldMoodTracker extends React.Component {
    getStreamOverlay() {
        if (this.state.enabled) {
            return (<StreamOverlay
                show={true} channel={}
                country={} onClose={this.onOverlayClose}/>);

    render() {
        return (


The corresponding props passed are used to render the component and connect to the stream from loklak server.

Creating Overlay Modal

On clicking the map, an overlay is shown. To display this overlay, react-overlays is used. The Modal component offered by the packages provides a very simple interface to define the design and interface of the component, including style, onclose hook, etc.

import {Modal} from 'react-overlays';

<Modal aria-labelledby='modal-label'
    <div style={dialogStyle()}>


It must be noted that modalStyle and backdropStyle are React style objects.

Dialog Style

The dialog style is defined to provide some space at the top, clicking where, the overlay is closed. To do this, vertical height units are used –

const dialogStyle = function () {
    return {
        position: 'absolute',
        width: '100%',
        top: '5vh',
        height: '95vh',
        padding: 20


Connecting to loklak Tweet Stream

loklak sends Server Sent Events to clients connected to it. To utilise this stream, we can use the natively supported EventSource object. Event stream is started with the render method of the StreamOverlay component –

render () {


This channel is used to connect to twitter/country/<country-ID> channel on the stream and then this can be passed to EventStream constructor. On receiving a message, a list of Tweets is appended and later rendered in the view –

startEventSource(country) {
    let channel = 'twitter%2Fcountry%2F' + country;
    if (this.eventSource) {
    this.eventSource = new EventSource(host + '/api/stream.json?channel=' + channel);
    this.eventSource.onmessage = (event) => {
        let json = JSON.parse(;
        if (this.state.tweets.length > 250) {


The size of the list is restricted to 250 here, so when a newer Tweet comes in, the oldest one is chopped off. And thanks to fast DOM actions in React, the rendering doesn’t take much time.

Rendering Tweets

The Tweets are displayed as simple cards on which user can click to open it on Twitter in a new tab. It contains basic information about the Tweet – screen name and Tweet text. Images are not rendered as it would make no sense to load them when Tweets are coming at a high rate.

function getTweetHtml(json) {
    return (
        <div style={{padding: '5px', borderRadius: '3px', border: '1px solid black', margin: '10px'}}>
            <a href={} target="_blank">
            <div style={{marginBottom: '5px'}}>
            <div style={{overflowX: 'hidden'}}>{json['text']}</div>


They are rendered using a simple map in the render method of StreamOverlay component –

<div className={styles.container} style={{'height': '100%', 'overflowY': 'auto',
    'overflowX': 'hidden', maxWidth: '100%'}}>


Closing Overlay

With the previous setup in place, we can now see Tweets from the loklak backend as they arrive. But the problem is that we will still be connected to the stream when we click-close the modal. Also, we would need to close the overlay from the parent component in order to stop rendering it.

We can use the onclose method for the Modal here –

close() {
    if (this.eventSource) {
        this.eventSource = null;


Here, props.onClose() disables rendering of StreamOverlay in the parent component.


In this blog post, I explained how the flow of props are used in the World Mood Tracker app to turn on and off the streaming in the overlay defined using react-overlays. This feature shows a basic setup for using the newly introduced stream API in loklak.

The motivation of such application was taken from emojitracker by mroth as mentioned in fossasia/ The changes were proposed in fossasia/ by @singhpratyush (me).

The app can be accessed live at


Adding Tweet Streaming Feature in World Mood Tracker loklak App

Snackbar for Error Handling in Twitter Followers Insight loklak App

In this blog post am going to explain how the Twitter Followers Insight app handles error which occurs when when no query is passed to the “Search” function i.e., when the search is proceeded with an empty query.

How to handle the Exception

In such cases, I have used SNACKBAR / TOAST. Snackbar / Toast is used to popup an error notification on the screen when an exception occurs.

Script for Snackbar / Toast:

In the below script, initially the error is set to null i.e., no error. The “showError” function is which is being called when there occurs a situation of no query or an empty query. The function below helps to show an error popup which only shows till a time limit.

    $scope.error = null;

    $scope.showError = function() {
        setTimeout(function(){ $(".snackbar").removeClass("show") }, 3000);


In this script, it checks whether the query passed is undefined or empty. If yes, then the error message which was null earlier is changed and that error is showed up on the screen to the end user. Snackbars animate upwards from the edge of the screen.

        if ($scope.query === '' || $scope.query === undefined) {
            $scope.spinner = false;
            $scope.error = "Please enter a valid Username";



Snackbar for Error Handling in Twitter Followers Insight loklak App

Know the Usage of all Emoji’s on Twitter with loklak Emoji Heatmap

Loklak apps page now has a new app in its store, Emoji Heatmap. This app can be used to see the usage of all the emoji’s in the tweets all over the world in the form of heatmap. So, the major difference between the emoji heatmap and emoji heatmapper apps are heatmapper shows the tweets related to specific search query whereas this heatmapper app, it displays all the tweets which contains emojis.

How do the App fetches and stores the locations

The emoji heatmap uses the loklak search API . The search API needs a query in order to search and output the JSON data. But this app takes no input from the user end to search any query. To make the search dynamic, we are using an existing JSON file from emojiHeatmapper app and loklak-fetcher-client javascript file. From the emoji.json file, we collect the each query item and search it using loklak-fetcher-client. The output json file which we get from loklak-fetcher-client is retrieved into the emojiHeatmap and we extract the location parameter. The location parameter is then stored into the “feature” option of open layers 3 maps.

So, here in the emoji Heatmap app, we iterate over the emoji.json, get different search query each time when we search for it using loklak search API.

Code which adds the location retrieved into feature

  $.getJSON("../emojiHeatmapper/emoji.json", function(json) {
    for (var i = 0; i <; i++){
      var query =[i][1];
      // Fetch loklak API data, and fill the vector
      loklakFetcher.getTweets(query, function(tweets) {
        for(var i = 0; i < tweets.statuses.length; i++) {
          if(tweets.statuses[i].location_point !== undefined){
          // Creation of the point with the tweet's coordinates
          //  Coords system swap is required: OpenLayers uses by default
          //  EPSG:3857, while loklak's output is EPSG:4326
            var point = new ol.geom.Point(ol.proj.transform(tweets.statuses[i].location_point, 'EPSG:4326', 'EPSG:3857'));
            vector.addFeature(new ol.Feature({  // Add the point to the data vector
              geometry: point,
              weight: 20


The above function gets has two variables query and point. The query variable stores the data that is being retrieved from the emoji.json file each time it iterates and that query is being sent into the loklak-fetcher-client. Then the point variable is in which the location tracked using the loklak search API is converted into the co-ordinates system followed by the Open Layers 3. Then the point is added as a feature to the map vector. The map vector is the place where all the features are stored and then appended onto the map as a heatmap.


Know the Usage of all Emoji’s on Twitter with loklak Emoji Heatmap

Adding React based World Mood Tracker to loklak Apps

loklak apps is a website that hosts various apps that are built by using loklak API. It uses static pages and angular.js to make API calls and show results from users. As a part of my GSoC project, I had to introduce the World Mood Tracker app using loklak’s mood API. But since I had planned to work on React, I had to go off from the track of typical app development in loklak apps and integrate a React app in

In this blog post, I will be discussing how I introduced a React based app to and solved the problem of country-wise visualisation of mood related data on a World map.

Setting up development environment inside

After following the steps to create a new app in, I needed to add proper tools and libraries for smooth development of the World Mood Tracker app. In this section, I’ll be explaining the basic configuration that made it possible for a React app to be functional in the angular environment.


The most obvious prerequisite for the project was Node.js. I used node v8.0.0 while development of the app. Instead of npm, I decided to go with yarn because of offline caching and Internet speed issues in India.

Webpack and Babel

To begin with, I initiated yarn in the app directory inside project and added basic dependencies –

$ yarn init
$ yarn add webpack webpack-dev-server path
$ yarn add babel-loader babel-core babel-preset-es2015 babel-preset-react --dev


Next, I configured webpack to set an entry point and output path for the node project in webpack.config.js

module.exports = {
    entry: './js/index.js',
    output: {
        path: path.resolve('.'),
        filename: 'index_bundle.js'

This would signal to look for ./js/index.js as an entry point while bundling. Similarly, I configured babel for es2015 and React presets –

    "es2015", "react"


After this, I was in a state to define loaders for module in webpack.config.js. The loaders would check for /\.js$/ and /\.jsx$/ and assign them to babel-loader (with an exclusion of node_modules).


After configuring the basic presets and loaders, I added React to dependencies of the project –

$ yarn add react react-dom


The React related files needed to be in ./js/ directory so that the webpack can bundle it. I used the file to create a simple React app –

import React from 'react';
import ReactDOM from 'react-dom';

    <div>World Mood Tracker</div>,


After this, I was in a stage where it was possible to use this app as a part of app. But to do this, I first needed to compile these files and bundle them so that the external app can use it.

Configuring the build target for webpack

In, we need to have a file by the name of index.html in the app’s root directory. Here, we also needed to place the bundled js properly so it could be included in index.html at app’s root.

HTML Webpack Plugin

Using html-webpack-plugin, I enabled auto building of project in the app’s root directory by using the following configuration in webpack.config.js

const HtmlWebpackPlugin = require('html-webpack-plugin');
const HtmlWebpackPluginConfig = new HtmlWebpackPlugin({
    template: './js/index.html',
    filename: 'index.html',
    inject: 'body'
module.exports = {
    plugins: [HtmlWebpackPluginConfig]


This would build index.html at app’s root that would be discoverable externally.

To enable bundling of the project using simple yarn build command, the following lines were added to package.json

  "scripts": {
    "build": "webpack -p"

After a simple yarn build command, we can see the bundled js and html being created at the app root.

Using datamaps for visualization

Datamaps is a JS library which allows plotting of data on map using D3 as backend. It provides a simple interface for creating visualizations and comes with a handy npm installation –

$ yarn add datamaps

Map declaration and usage as state

A map from datamaps was used a state for React component which allowed fast rendering of changes in the map as the state of React component changes –

export default class WorldMap extends React.Component {
    constructor() {
        this.state = {
            map: null
    render() {
        return (<div className={styles.container}>
                <div id="map-container"></div></div>)
    componentDidMount() {
        this.setState({map: new Datamap({...})});


The declaration of map goes in componentDidMount method because it would not be possible to start the map until we have the div with id=”map-container” in the DOM. It was necessary to draw the map only after the component has mounted otherwise it would fail due to no id=”map-container” in the DOM.

Defining data for countries

Data for every country had two components –

data = {
    positiveScore: someValue,
    negativeScore: someValue


This data is used to generate popup for the counties –

    map: new Datamap({
        geographyConfig: {
            popupTemplate: function (geo, data) {
                // Configure variables pScore so that it gives “No Data” when data.positiveScore is not set (similar for negative)
                return [
                    // Use pScore and nScore to generate results here
                    // would give current country name

The result for countries with unknown data values look something like this –


In this blog post, I explained about introducing a React based app in’s angular based environment. I discussed the setup and bundling process of the project so it becomes available from the project’s external HTTP server.

I also discussed using datamaps as a visualisation tool for data about Tweets. The app was first introduced in pull request fossasia/ and was improved step by step in subsequent patches.


Adding React based World Mood Tracker to loklak Apps

CSS Styling Tips Used for loklak Apps

Cascading Style Sheets (CSS) is one of the main factors which is valuable to create beautiful and dynamic websites. So we use CSS for styling our apps in

In this blog post am going to tell you about few rules and tips for using CSS when you style your App:

1.Always try something new – The loklak apps website is very flexible according to the user whomsoever creates an app. The user is always allowed to use any new CSS frameworks to create an app.

2.Strive for Simplicity – As the app grows, we’ll start developing a lot more than we imagine like many CSS rules and elements etc. Some of the rules may also override each other without we noticing it. It’s good practice to always check before adding a new style rule—maybe an existing one could apply.

3.Proper Structured file –

  • Maintain uniform spacing.
  • Always use semantic or “familiar” class/id names.
  • Follow DRY (Don’t Repeat Yourself) Principle.

CSS file of Compare Twitter Profiles App:

#searchBar {

table {
  border-collapse: collapse;
  width: 70%;

th, td {
  padding: 8px;
  text-align: center;
  border-bottom: 1px solid#ddd;


The output screen of the app:

Do’s and Don’ts while using CSS:

  • Pages must continue to work when style sheets are disabled. In this case this means that the apps which are written in should run in any and every case. Let’s say for instance, when a user uses a old browsers or bugs or either because of style conflicts.
  • Do not use the !important attribute to override the user’s settings. Using the !important declaration is often considered bad practice because it has side effects that mess with one of CSS’s core mechanisms: specificity. In many cases, using it could indicate poor CSS architecture.
  • If you have multiple style sheets, then make sure to use the same CLASS names for the same concept in all of the style sheets.
    Do not use more than two fonts. Using a lot of fonts simply because you can will result in a messy look.
  • A firm rule for home page design is more is less : the more buttons and options you put on the home page, the less users are capable of quickly finding the information they need.


CSS Styling Tips Used for loklak Apps

Welcoming Wiki GeoData to Loklak !

Loklak has grown vast with due course of time and it’s capabilities have extended manifold especially by the inclusion of sundry website scraper services and data provider services.


The recent addition includes a special service which would provide the user with a list of Wikipedia articles tagged with the location when supplied with a specific name of the place.

Thanks to the Media Wiki GeoData API, this service was smoothly integrated in the Loklak Server and SUSI (our very own cute and quirky personal digital assistant)

When the name of the place is sent in the query , firstly the home-grown API was utilized to get the location co-ordinates i.e. Latitude and Longitude.

URL getCoordURL = null;

String path = "data={\"places\":[\"" + place + "\"]}";

try {
    getCoordURL = new URL("" + path);
} catch (MalformedURLException e) {

JSONTokener tokener = null;
try {
    tokener = new JSONTokener(getCoordURL.openStream());
} catch (Exception e1) {

JSONObject obj = new JSONObject(tokener);

String longitude = obj.getJSONObject("locations").getJSONObject(place).getJSONArray("location").get(0)
String lattitude = obj.getJSONObject("locations").getJSONObject(place).getJSONArray("location").get(1)

The resultant geographical co-ordinates were then passed on to the Media Wiki GeoData API with other parameters like the radius of the geographical bound to be considered and format of the resultant data along-with the co-ordinates to obtain a list of Page IDs of the corresponding Wikipedia Articles besides Title and Distance.

URL getWikiURL = null;

try {
    getWikiURL = new URL(
                      "" + latitude
			+ "|" + longitude + "&format=json");
} catch (MalformedURLException e) {

JSONTokener wikiTokener = null;

try {
    wikiTokener = new JSONTokener(getWikiURL.openStream());
} catch (Exception e1) {

JSONObject wikiGeoResult = new JSONObject(wikiTokener);

When implemented as a Console Service for Loklak, the servlet was registered as /api/wikigeodata.json?place={place-name} and the API endpoint for example goes like http://localhost:9000/api/console.json?q=SELECT * FROM wikigeodata WHERE place=’Singapore’;

Presto !!

We have a JSON Object as the result with a list of Wikipedia Articles as:


The Page-IDs thus obtained can now be utilized very easily to diaply the articles by using the placeholder{pageid} for the purpose.

And this way, another facility was included in our diversifying Loklak server.

Questions, feedback, suggestions appreciated 🙂

Welcoming Wiki GeoData to Loklak !

Loklak fuels Open Event

A general background building….

The FOSSASIA Open Event Project aims to make it easier for events, conferences, tech summits to easily create Web and Mobile (only Android currently) micro Apps. The project comprises of a data schema for easily storing event details, a server and web front-end that are used to view, modify, update this data easily by the event organizers, a mobile-friendly web-app client to show the event data to attendees, an Android app template which will be used to generate specific apps for each event.

And Eventbrite is the world’s largest self-service ticketing platform. It allows anyone to create, share and find events comprising music festivals, marathons, conferences, hackathons, air guitar contests, political rallies, fundraisers, gaming competitions etc.

Kaboom !

Loklak now has a dedicated Eventbrite scraper API which takes in the URL of the event listing on and outputs JSON Files as required by the Open Event Generator viz: events.json, organizer.json, user.json, microlocations.json, sessions.json, session_types.json, tracks.json, sponsors.json, speakers.json, social _links.json and custom_forms.json (details: Open Event Server : API Documentation)

What do we differently do than using the Eventbrite API  ? No authentication tokens required. This gels in perfectly with the Loklak missive.

To achieve this, I have simply parsed the HTML Pages using my favorite JSoup: The Java HTML parser library because it provides a very convenient API for extracting and manipulating data, scrape and parse all varieties of HTML from a URL.

The API call format is as:[event-name-and-id]

And in return we get all the details on the Eventbrite page as JSONObject and also it gets stored in differently named files in a zipped folder [userHome + “/Downloads/EventBriteInfo”]


Event URL:
Screenshot from 2016-07-04 07:04:38

API Call:

Output: JSON Object on screen andevents.json, organizer.json, user.json, microlocations.json, sessions.json, session_types.json, tracks.json, sponsors.json, speakers.json, social _links.json and custom_forms.json files written out in a zipped folder locally.

Screenshot from 2016-07-04 07:05:16
Screenshot from 2016-07-04 07:57:00

For reference, the code is as:

 * Crawler v2.0
 *  Copyright 19.06.2016 by Jigyasa Grover, @jig08
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  Lesser General Public License for more details.
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program in the file lgpl21.txt
 *  If not, see



import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.json.JSONArray;
import org.json.JSONObject;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.loklak.http.RemoteAccess;
import org.loklak.server.Query;

public class EventbriteCrawler extends HttpServlet {

	private static final long serialVersionUID = 5216519528576842483L;

	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		Query post = RemoteAccess.evaluate(request);

		// manage DoS
		if (post.isDoS_blackout()) {
			response.sendError(503, "your request frequency is too high");

		String url = post.get("url", "");

		Document htmlPage = null;

		try {
			htmlPage = Jsoup.connect(url).get();
		} catch (Exception e) {

		String eventID = null;
		String eventName = null;
		String eventDescription = null;

		// TODO Fetch Event Color
		String eventColor = null;

		String imageLink = null;

		String eventLocation = null;

		String startingTime = null;
		String endingTime = null;

		String ticketURL = null;

		Elements tagSection = null;
		Elements tagSpan = null;
		String[][] tags = new String[5][2];
		String topic = null; // By default

		String closingDateTime = null;
		String schedulePublishedOn = null;
		JSONObject creator = new JSONObject();
		String email = null;

		Float latitude = null;
		Float longitude = null;

		String privacy = "public"; // By Default
		String state = "completed"; // By Default
		String eventType = "";

		eventID = htmlPage.getElementsByTag("body").attr("data-event-id");
		eventName = htmlPage.getElementsByClass("listing-hero-body").text();
		eventDescription ="").text();

		eventColor = null;

		imageLink = htmlPage.getElementsByTag("picture").attr("content");

		eventLocation ="p.listing-map-card-street-address.text-default").text();
		startingTime = htmlPage.getElementsByAttributeValue("property", "event:start_time").attr("content").substring(0,
		endingTime = htmlPage.getElementsByAttributeValue("property", "event:end_time").attr("content").substring(0,

		ticketURL = url + "#tickets";

		// TODO Tags to be modified to fit in the format of Open Event "topic"
		tagSection = htmlPage.getElementsByAttributeValue("data-automation", "ListingsBreadcrumbs");
		tagSpan ="span");
		topic = "";

		int iterator = 0, k = 0;
		for (Element e : tagSpan) {
			if (iterator % 2 == 0) {
				tags[k][1] = ""
			} else {
				tags[k][0] = e.text();

		creator.put("email", "");
		creator.put("id", "1"); // By Default

		latitude = Float
				.valueOf(htmlPage.getElementsByAttributeValue("property", "event:location:latitude").attr("content"));
		longitude = Float
				.valueOf(htmlPage.getElementsByAttributeValue("property", "event:location:longitude").attr("content"));

		// TODO This returns: "events.event" which is not supported by Open
		// Event Generator
		// eventType = htmlPage.getElementsByAttributeValue("property",
		// "og:type").attr("content");

		String organizerName = null;
		String organizerLink = null;
		String organizerProfileLink = null;
		String organizerWebsite = null;
		String organizerContactInfo = null;
		String organizerDescription = null;
		String organizerFacebookFeedLink = null;
		String organizerTwitterFeedLink = null;
		String organizerFacebookAccountLink = null;
		String organizerTwitterAccountLink = null;

		organizerName ="a.js-d-scroll-to.listing-organizer-name.text-default").text().substring(4);
		organizerLink = url + "#listing-organizer";
		organizerProfileLink = htmlPage
				.getElementsByAttributeValue("class", "js-follow js-follow-target follow-me fx--fade-in is-hidden")
		organizerContactInfo = url + "#lightbox_contact";

		Document orgProfilePage = null;

		try {
			orgProfilePage = Jsoup.connect(organizerProfileLink).get();
		} catch (Exception e) {

		organizerWebsite = orgProfilePage.getElementsByAttributeValue("class", "l-pad-vert-1 organizer-website").text();
		organizerDescription ="div.js-long-text.organizer-description").text();
		organizerFacebookFeedLink = organizerProfileLink + "#facebook_feed";
		organizerTwitterFeedLink = organizerProfileLink + "#twitter_feed";
		organizerFacebookAccountLink = orgProfilePage.getElementsByAttributeValue("class", "fb-page").attr("data-href");
		organizerTwitterAccountLink = orgProfilePage.getElementsByAttributeValue("class", "twitter-timeline")

		JSONArray socialLinks = new JSONArray();

		JSONObject fb = new JSONObject();
		fb.put("id", "1");
		fb.put("name", "Facebook");
		fb.put("link", organizerFacebookAccountLink);

		JSONObject tw = new JSONObject();
		tw.put("id", "2");
		tw.put("name", "Twitter");
		tw.put("link", organizerTwitterAccountLink);

		JSONArray jsonArray = new JSONArray();

		JSONObject event = new JSONObject();
		event.put("event_url", url);
		event.put("id", eventID);
		event.put("name", eventName);
		event.put("description", eventDescription);
		event.put("color", eventColor);
		event.put("background_url", imageLink);
		event.put("closing_datetime", closingDateTime);
		event.put("creator", creator);
		event.put("email", email);
		event.put("location_name", eventLocation);
		event.put("latitude", latitude);
		event.put("longitude", longitude);
		event.put("start_time", startingTime);
		event.put("end_time", endingTime);
		event.put("logo", imageLink);
		event.put("organizer_description", organizerDescription);
		event.put("organizer_name", organizerName);
		event.put("privacy", privacy);
		event.put("schedule_published_on", schedulePublishedOn);
		event.put("state", state);
		event.put("type", eventType);
		event.put("ticket_url", ticketURL);
		event.put("social_links", socialLinks);
		event.put("topic", topic);

		JSONObject org = new JSONObject();
		org.put("organizer_name", organizerName);
		org.put("organizer_link", organizerLink);
		org.put("organizer_profile_link", organizerProfileLink);
		org.put("organizer_website", organizerWebsite);
		org.put("organizer_contact_info", organizerContactInfo);
		org.put("organizer_description", organizerDescription);
		org.put("organizer_facebook_feed_link", organizerFacebookFeedLink);
		org.put("organizer_twitter_feed_link", organizerTwitterFeedLink);
		org.put("organizer_facebook_account_link", organizerFacebookAccountLink);
		org.put("organizer_twitter_account_link", organizerTwitterAccountLink);

		JSONArray microlocations = new JSONArray();

		JSONArray customForms = new JSONArray();

		JSONArray sessionTypes = new JSONArray();

		JSONArray sessions = new JSONArray();

		JSONArray sponsors = new JSONArray();

		JSONArray speakers = new JSONArray();

		JSONArray tracks = new JSONArray();

		JSONObject eventBriteResult = new JSONObject();
		eventBriteResult.put("Event Brite Event Details", jsonArray);

		// print JSON
		PrintWriter sos = response.getWriter();

		String userHome = System.getProperty("user.home");
		String path = userHome + "/Downloads/EventBriteInfo";

		new File(path).mkdir();

		try (FileWriter file = new FileWriter(path + "/event.json")) {
		} catch (IOException e1) {

		try (FileWriter file = new FileWriter(path + "/org.json")) {
		} catch (IOException e1) {

		try (FileWriter file = new FileWriter(path + "/social_links.json")) {
		} catch (IOException e1) {

		try (FileWriter file = new FileWriter(path + "/microlocations.json")) {
		} catch (IOException e1) {

		try (FileWriter file = new FileWriter(path + "/custom_forms.json")) {
		} catch (IOException e1) {

		try (FileWriter file = new FileWriter(path + "/session_types.json")) {
		} catch (IOException e1) {

		try (FileWriter file = new FileWriter(path + "/sessions.json")) {
		} catch (IOException e1) {

		try (FileWriter file = new FileWriter(path + "/sponsors.json")) {
		} catch (IOException e1) {

		try (FileWriter file = new FileWriter(path + "/speakers.json")) {
		} catch (IOException e1) {

		try (FileWriter file = new FileWriter(path + "/tracks.json")) {
		} catch (IOException e1) {

		try {
			zipFolder(path, userHome + "/Downloads");
		} catch (Exception e1) {


	static public void zipFolder(String srcFolder, String destZipFile) throws Exception {
		ZipOutputStream zip = null;
		FileOutputStream fileWriter = null;
		fileWriter = new FileOutputStream(destZipFile);
		zip = new ZipOutputStream(fileWriter);
		addFolderToZip("", srcFolder, zip);

	static private void addFileToZip(String path, String srcFile, ZipOutputStream zip) throws Exception {
		File folder = new File(srcFile);
		if (folder.isDirectory()) {
			addFolderToZip(path, srcFile, zip);
		} else {
			byte[] buf = new byte[1024];
			int len;
			FileInputStream in = new FileInputStream(srcFile);
			zip.putNextEntry(new ZipEntry(path + "/" + folder.getName()));
			while ((len = > 0) {
				zip.write(buf, 0, len);

	static private void addFolderToZip(String path, String srcFolder, ZipOutputStream zip) throws Exception {
		File folder = new File(srcFolder);

		for (String fileName : folder.list()) {
			if (path.equals("")) {
				addFileToZip(folder.getName(), srcFolder + "/" + fileName, zip);
			} else {
				addFileToZip(path + "/" + folder.getName(), srcFolder + "/" + fileName, zip);


Check out for more…


Feel free to ask questions regarding the above code snippet.

Also, Stay tuned for the next part of this post which shall include using the scraped information for Open Event.

Feedback and Suggestions welcome 🙂

Loklak fuels Open Event

The apps page gets a makeover

Huge transformations took place in the apps section. It’s amazing to see the count of the Loklak apps shoot up. There are more than 20 apps built using various APIs provided by Loklak. Inorder to dynamically manage the apps, apps.json was introduced.


Initially there was a simple card layout. With the required name and the description of the app.


The new tiles design has screenshots of the app and the details of the app is shown when the mouse is hovered on the screenshot. The apps are categorized based on the type of API being used. Accordingly the left navigation bar consists of all the categories.

This page is dynamic and takes the data from a new JSON object from apps API. It has all the apps and their details along with fields like categories list and the corresponding apps under it.


The above array “categories” was used to get all the list of categories on the left navigation bar.


The above category object is being used for getting the list of the apps under each specified category. This is being used to display the app’s details when a specific category is being clicked.

The above JSON made it easy to categorize the apps into various sections and gave a new look to the page. The tiles design was completely designed using standard CSS classes. The page is responsive and dynamic.

The apps page gets a makeover