Writing Browser Specific CSS for Susper in Angular

In Susper, we were facing a unique problem for Information box and Analytics box alignment.
At a width of around 1290 px, the boxes fit perfectly in Firefox as shown:

However, they were slipping to the next line in Google Chrome browsers for the same dimension(1290 px)

The solution to this issue was to write browser-specific CSS.
The two most commonly used browser specific tags are

  1. @-moz-document url-prefix() { }: This tag is used to target the Mozilla Firefox browser in particular. Anything written within the curly braces will not apply to any other browser.
  2. @media screen and (-webkit-min-device-pixel-ratio:0) { }: This tag is used to target all browsers that support webkit such as Chrome, Safari etc.

For our problem, we need to use @media screen and (-webkit-min-device-pixel-ratio:0) { }
This was how the code was written for both the components (Information box and Analytics box). Please refer to infobox.component.css and statsbox.component.css for the entire code.

@media screen and (-webkit-min-device-pixel-ratio:0) {
@media screen and (max-width: 1300px) {
.card {
width: 366px;
@media screen and (max-width: 1280px) {
.card {
width: 366px;

As a result of this snippet of code, we see the following effects:

  • In Chrome, the boxes change to a smaller width at 1300px itself, thus preventing it from slipping to the next line
  • In Firefox, the boxes change to a smaller width only at 1280px, and not at 1300px, thus achieving the exact design we envisioned.

This is how the display finally looks in Chrome:


  1. Stack overflow on specific CSS tags for Chrome: https://stackoverflow.com/questions/9328832/how-to-apply-specific-css-rules-to-chrome-only
  2. Stack overflow on specific CSS tags for Firefox: https://stackoverflow.com/questions/952861/targeting-only-firefox-with-css

Making a Sticky Top Navigation bar for Susper using Angular

A lot of websites, require a top navigation bar that sticks to the top, irrespective of the screen dimension size. This blog deals with how the top navigation bar was made sticky in Susper.

  1. Using the correct Bootstrap classes. Notice the code enveloping the navigation bar.

<nav class=“top-nav navbar navbar-static-top navbar-default”>


class=“navbar-header” id=“navcontainer”>


Points to note:

  • Using navbar and navbar-default creates a standard gray navigation bar.
  • Using navbar-static-top makes the navbar stick only to the top of the page and disappear on scrolling down.
  • Using container-fluid creates a container for the contents of the navbar with wide margins
  1.  Now we also need to write some personalized CSS code. Notice the classes navcontainer and  top-nav. This is the CSS code for these classes:

margin-bottom: 0;
#navcontainer {
height: 65px;
width: 100vw;
}#navcontainer ul {
margin: 0;
padding: 0;
list-style-type: none;

Points to note:

  • Margin and padding can be set according to how the navbar should look. Click here to know the difference between margins and padding.
  • The height has been customized to 65px in Susper, with a width of 100vw(entire viewpost width).
  1. Lastly, if your navigation bar is inside the body tag, remember that by default, body has a top margin of 57 px. As a result you may see an extra white space on top of your navigation bar. To remove this:
  • Move the navigation bar code out of the body tag. If you can’t then,
  • Place your navigation bar in a container ( resultContainer on the Susper result page) and write this in your CSS file.

margin-top: -57px;


Making Customized and Mobile Responsive Drop-down Menus in Susper using Angular

In  Susper, the drop-down menu is customized with colorful search icons and we wanted to maintain the same menu for mobile screens too, however the drop-down menu disappeared for all screens with width less than 767px. This blog can be used to learn how to create css classes for such drop-down menus without using any bootstrap.
This is how the issue was solved.

  1. Replacing standard bootstrap classes : The drop-down menu blocks had a source code as follows:






Using col-sm-4 will do the following

  • For widths greater than 767px: Divide each row into four equally sized columns.
  • For widths smaller than 767px: Stack all the columns on top of each other.

Since the drop-down menu’s design was to remain intact, I made the following changes:

  • Replace row with menu-row
  • Replace col-sm-4 with menu-item

Now I wrote personalized css for these classes.

width: 267px;
gridtemplatecolumns: 1fr 1fr 1fr;
background-color: white;
display: inlineblock;
width: 86px;
  • Width: It is used to set the width of the div class, each row now has a width of 267px, with each column in it having a width of 86px.
  • Grid-template-columns: It is used to layout the structure of the template, here 1fr 1fr 1fr represents that there will be three columns in a row.
  • Display: The display is set to inline block to overwrite the default property of the div element to start in a new line.
  1. Custom css for small screens : In standard bootstrap, for screen sizes less than 767px, dropdown class has properties like transparent background, no border etc. that need to be over written. So we add a new id for the div tag as shown:

<div id=“small-drop” class=“dropdown-menu”>

/** Now we add css for it, as shown: **/
@media screen and (max-width: 767px) {
position: absolute;
background-color: white;
border: 1px solid #cccccc;
right: -38px;
left: auto;

  • Position : absolute is used to make sure all our values are absolute and not relative to the higher div hierarchically
  • Border: The values for the border represent the following respectively: Thickness, Style and Color.
  • Auto: Here the value auto for left signifies that there is no fixed value for the left margin, it can take the default value


  1. For working of grids in Bootstrap: https://www.w3schools.com/bootstrap/bootstrap_grid_examples.asp
  2. A useful article for difference between id and class: https://css-tricks.com/the-difference-between-id-and-class


Scaling the logo of the generated events properly in Open Event Webapp

In the Facebook Developer Conference, the logo was too small


In the Open Tech Summit Event, the logo was too long and increased the height of the navigation bar


We decide some constraints regarding the width and the height of the logo. We don’t want the width of the logo to exceed greater than 110 pixels in order to not let it become too wide. It would look odd on small and medium screen if barely passable on bigger screens. We also don’t want the logo to become too long so we set a max-height of 45 pixels on the logo. So, we apply a class on the logo element with these properties

.logo-image {
 max-width: 110px;
 max-height: 45px;

But simply using these properties doesn’t work properly in some cases as shown in the above screenshots. An alternative approach is to resize the logo appropriately during the generation process itself. There are many different ways in which we can resize the logo. One of them was to scale the logo to a fixed dimension during the generation process. The disadvantage of that approach was that the event logo comes in different size and shapes. So resizing them to a fixed size will change its aspect ratio and it will appear stretched and pixelated. So, that approach is not feasible. We need to think of something different.  After a lot of thinking, we came up with an algorithm for the problem. We know the height of the logo would not be greater than 45px. We calculate the appropriate width and height of the logo, resize the image, and calculate dynamic padding which we add to the anchor element (inside which the image is located) if the height of the image comes out to be less than 45px. This is all done during the generation of the app. Note that the default padding is 5px and we add the extra pixels on top of it. This way, the logo doesn’t appear out of place or pixelated or extra wide and long. The detailed steps are mentioned below

  • Declare variable padding = 5px
  • Get the width, height and aspect ratio of the image.
  • Set the height to 45px and calculate the width according to the aspect ratio. If the width <= 110px, then directly resize the image and no change in padding is necessary
  • If the width > 110px, then make width constant to 110px and calculate height according to the aspect ratio. It will surely come less than 45px. Subtract the difference = (45 – height), divide it by 2 and add it to the padding variable.
  • Apply padding variable on the anchor tag. Now every logo should be displayed nicely and we have fixed the height of the navigation bar = 55px for all cases.

Here is an excerpt of the code. The whole work and discussion can be viewed here

var optimizeLogo = function(image, socket, done) {
 sharp(image).metadata(function(err, metaData) {
   if(err) {
     return done(err);
   var width = metaData.width;
   var height = metaData.height;
   var ratio = width/height;
   var padding = 5;
   var diffHeight = 0;

   height = 45;
   width = Math.floor(45 * ratio);
   if (width > 110) {
     width = 110;
     height = Math.floor(width/ratio);
     diffHeight = 45 - height;
     padding = padding + (diffHeight)/2;
   sharp(image).resize(width, height).toFile(image + '.new', function(err, info) {
     return done(null, padding);

It solved the problem. Now the logos of all the events were displaying properly. They were neither too wide, long or short. Here are some screenshots to show the improvements.

Facebook Developer Conference


Open Tech Summit 2017



Reducing Initial Load Time Of Susper

Susper used to take long time to load the initial page. So, there was a discussion on how to decrease the initial loading time of Susper.

Later on going through issues raised in official Angular repository regarding the time takento load angular applications, we found some of the solutions. Those include:

  • Migrating from development to production during build:
    • This shrinks vendor.js and main.js by minimising them and also removing all packages that are not required on production.
    • Enables inline html and extracting CSS.
    • Disables source maps.
  • Enable Ahead of Time (AoT) compilation.
  • Enable service workers.

After these changes we found the following changes in Susper:

File Name Before (content-length) After
vendor.js 709752 216764
main.js 56412 138361



Vendor file:



Vendor file:


Also we could see that all files are now initiated by service worker:

More about Service Workers could be read at Mozilla and Service Workers in Angular.


While deploying our application, we have added –prod and –aot as extra attributes to ng build .This enables angular to use production mode and ahead of time compilation.

For service workers we have to install @angular/service-worker module. One can install it by using:

npm install @angular/service-worker --save
ng set apps.0.serviceWorker=true

The whole implementation of this is available at this pull:





Adding Transition Effect Using RxJS And CSS In Voice Search UI Of Susper


Susper has been given a voice search feature through which it provides a user with a better experience of search. We introduced to enhance the speech-recognition user interface by adding transition effects. The transition effect was required to display appropriate messages according to voice being detected or not. The following messages were:

  • When a user should start a voice search, it should display ‘Speak Now’ message for 1-2 seconds and then show up with message ‘Listening…’ to acknowledge user that now it is ready to recognize the voice which will be spoken.
  • If a user should do not speak anything, it should display ‘Please check audio levels or your microphone working’ message in 3-4 seconds and should exit the voice search interface.

The idea of speech UI was taken from the market leader and it was implemented in a similar way. On the homepage, it looks like this:

On the results page, it looks like this:

For creating transitions like, ‘Listening…’ and ‘Please check audio levels and microphone’ messages, we used CSS, RxJS Observables and timer() function.

Let’s start with RxJS Observables and timer() function.

RxJS Observables and timer()

timer() is used to emit numbers in sequence in every specified duration or after a given duration. It acts as an observable. For example:

let countdown = Observable.timer(2000);
The above code will emit value of countdown in 2000 milliseconds. Similarly, let’s see another example:
let countdown = Observable.timer(2000, 6000);
The above code will emit value of countdown in 2000 milliseconds and subsequent values in every 6000 milliseconds.
export class SpeechToTextComponent implements OnInit {
  message: any = ‘Speak Now’;
  timer: any;
  subscription: any;
  ticks: any;
  miccolor: any = #f44;
ngOnInit() {
  this.timer = Observable.timer(1500, 2000);
  this.subscription = this.timer.subscribe(t => {
  this.ticks = t;// it will throw listening message after 1.5   sec
  if (t === 1) {
    this.message = Listening;
  }// subsequent events will be performed in 2 secs interval
  // as it has been defined in timer()
  if (t === 4) {
    this.message = Please check your microphone audio levels.;
    this.miccolor = #C2C2C2;
}// if no voice is given, it will throw audio level message
// and unsubscribe to the event to exit back on homepage
  if (t === 6) {
    this.store.dispatch(new speechactions.SearchAction(false));
The above code will throw following messages at a particular time. For creating the text-animation effect, most developers go for plain javascript. The text-animation effects can also be achieved by using pure CSS.

Text animation using CSS

@webkitkeyframes typing {from {width:0;}}
.spch {
  fontweight: normal;
  lineheight: 1.2;
  pointerevents: none;
  position: none;
  textalign: left;
  –webkitfontsmoothing: antialiased;
  transition: opacity .1s easein, marginleft .5s easein,                  top  0s linear 0.218s;
  –webkitanimation: typing 2s steps(21,end), blinkcaret .5s                       stepend infinite alternate;
  whitespace: nowrap;
  overflow: hidden;
  animationdelay: 3.5s;
@keyframes specifies animation code. Here width: 0; tells that animation begins from 0% width and ends to 100% width of the message. Also, animation-delay: 3.5s has been adjusted w.r.t timer to display messages with animation at the same time.
This is how it works now:

The source code for the implementation can be found in this pull request: https://github.com/fossasia/susper.com/pull/663




Implementing Intelligence Feature in Susper

Susper gives answers to your questions using SUSI AI. We want to give users best experience while they are searching for solutions to their questions. To achieve this, we have incorporated with features like infobox and intelligence using SUSI.

Google has this feature where users can ask questions like ‘Who is president of USA?’ and get answers directly without encouraging the users to deep-dive into the search results to know the answer.

Similarly Susper gives answer to the user:

It also gives answer to question which is related to real time data like temperature.


How we have implemented this feature?

We used the API Endpoint of SUSI at http://api.asksusi.com/

Using SUSI API is as simple as sending query as a URL parameter in GET request http://api.susi.ai/susi/chat.json?q=YOUR_QUERY

You can also get various action types in the response. Eg: An anwser type response for http://api.susi.ai/susi/chat.json?q=hey%20susi is:

actions: [
    type: "answer",
    expression: "Hi, I'm Susi"


Documentation regarding SUSI is available at here.

Implementation in Susper:

We have created an Intelligence component to display answer related to a question. You can check it here: https://github.com/fossasia/susper.com/tree/master/src/app/intelligence

It takes care about rendering the information and styling of the rendered data received from SUSI API.

The intelligence.component.ts makes a call to Intelligence Service with the required query and the intelligence service makes a GETrequest to the SUSI API and retrieves the results.


this.intelligence.getintelligentresponse(data.query).subscribe(res => {
  if (res && res.answers && res.answers[0].actions) {
     this.actions = res.answers[0].actions;
       for (let action of this.actions) {
         if (action.type === 'answer' && action.mood !== 'sabta') {
           this.answer = action.expression;
         } else {
             this.answer = '';
   } else {
       this.answer = '';



export class IntelligenceService {
 server = 'http://api.susi.ai';
 searchURL = 'http://' + this.server + '/susi/chat.json';
 constructor(private http: Http, private jsonp: Jsonp, private store: Store<fromRoot.State>) {
 getintelligentresponse(searchquery) {
   let params = new URLSearchParams();
   params.set('q', searchquery);
   params.set('callback', 'JSONP_CALLBACK');
   return this.jsonp
     .get('http://api.asksusi.com/susi/chat.json', {search: params}).map(res =>


Whenever the getintelligenceresponse of intelligenceService is called, it creates a URLSearchParams() object and set required parameters in it and send them in jsonp.get request. We also set callback to ‘JSONP_CALLBACK’ to inform the API to send us data in JSONP.

Thereby, the intelligence component retrieves the answer and displays it with search resultson Susper.

Source code for this implementation could be found in this pull:



Changing Dimensions of Search Box Dynamically in Susper

Earlier the Susper search box had a fixed dimension. When a user types in a query, the dimensions of the search box remained fixed. This approach resulted in several issues like:

  • Matching the dimensions of the search bar following the market leader.
  • When dimensions are dynamically changing, it should not disturb alignment w.r.t tabs in the results page.

What actually happens is, when a user enters a query, the search box quickly changes its dimensions when results appear. I will be discussing below how we achieved this goal.

On the home page, we created the dimensions of a search bar with 584 x 44 pixels.

On the results page, we created the dimensions of search bar 632 x 44 similar to market leader:

How we proceeded?

Susper is built on Angular v4.1.3. It automatically comes with a function ngOnInit() whenever a new component has been created. ngOnInit() is a part of life cycle hook in Angular 4 (in Angular 2 as well). The function is called up or initialized when the component is rendered completely. This was the key for changing dimensions of search bar dynamically as soon as a component is created.

What happens is when a user types a query on the homepage and hits enter then, results component is created. As soon as, it is created – ngOnInit() function is called.

The default dimensions of search bar have been provided as follows:


#navgroup {
  height: 44px;
  width: 584px;
When the homepage loads up, dimensions by default are 584 x 44.


private navbarWidth: any;
ngOnInit() {
  this.navbarWidth = 632px;


We used [style.width] attribute to change the dimensions dynamically. Add this attribute inside input element.

<input #input type=“text” name=“query” class=“form-control” id=“nav-input” (ngModelChange)=“onquery($event)” [(ngModel)]=“searchdata.query” autocomplete=“off” (keypress)=“onEnter($event)” [style.width]=“navbarWidth”>
As soon as results component is loaded, the dimensions of search bar change to 632 x 44. In this way, we change the dimensions of search bar dynamically as soon as results are loaded.


Aligning Images to Same Height Maintaining Ratio in Susper

In this blog, I’ll be sharing the idea how we have perfectly aligned images to the same height in Susper without disturbing their ratio. When it comes to aligning images perfectly, they should have:

  • Same height.
  • A proper ratio to maintain the image quality. Many developers apply same width and height without keeping in mind about image ratio which results in:
    • Blurred image,
    • Image with a lot of pixels,
    • Cropping of an image.

Earlier Susper was having image layout like this:

In the screenshot, images are not properly aligned.  They are also not having the same height. We wanted to improve the layout of images just like market leaders Google and DuckDuckGo.

  • How we implemented a better layout for images?

<div class=“container”>
  <div class=“grid” *ngIf=“Display(‘images’)”>
    <div class=“cell” *ngFor=“let item of item$ | async”>
      <a class=“image-pointer” href=“{{item.link}}”>
        <img class=“responsive-image” src=“{{item.link}}”></a>
I have created a container, in which images will be loaded from yacy server. Then I have created a grid with an equal number of rows and column. I have adjusted the height and width of rows and columns to obtain a grid which contains each division as a cell. The image will load inside the cell. Each cell consists of one image.
.grid {
  paddingleft: 80px;
.container {
  width: 100%;
  margin: 0;
  top: 0;
  bottom: 0;
  padding: 0;

After implementing it, we were facing issues like cropping of the image inside a cell. So, to avoid cropping and maintain the image ratio we introduced .responsive-image class which will avoid cropping of images inside cell.

.responsiveimage {
  maxwidth: 100%;
  height: 200px;
  paddingtop: 20px;
  padding: 0.6%;
  display: inlineblock;
  float: left;

This is how Susper’s image section looks now:

It took some time to align images, but somehow we succeeded in creating a perfect layout for the images.

We are facing some issues regarding images. Some of them don’t appear due to broken link. This issue will be resolved soon on the server.


Implementation of Responsive SUSI Web Chat Search Bar

When we were building the first phase of the SUSI Web Chat Application we didn’t consider about  the responsiveness as a main goal. The main thing we needed was a working application. This changed at a later stage. In this post I’m going to emphasize how we implemented the responsive design and problems we met while we were developing the design.

When we were moving to Material-UI from static HTML CSS we were able to make most of the parts responsive. As an example App-bar of the application. We added App-bar like as follows: We made a separate component for App-bar and it includes the “searchfield” element. Material-UI app bar handles the responsiveness for some extent. We have to handle responsiveness of other sub-parts of the app bar manually.

In “TopBar.react.js” I returned marterial-ui <Toolbar> element like this.

                <ToolbarGroup >
                <ToolbarGroup lastChild={true}> //inside of this we have to include other components of the top bar inside this element


We have to add the search button inside the element.
In this we added search component.

This field has the ability to expand and collapse like this.

It looks good. But it appears on mobile screen in a different way. This is how it appears on mobile devices.

So we wanted to hide the SUSI logo on small sized screens. For that we wrote medial queries like this.

@media only screen and (max-width: 860px){
   background-image: none;
   width: 100px !important;

Even in smaller screens it appears like this.

To avoid that we minimized the width of the search bar in different screen sizes using media queries .

@media only screen and (max-width: 480px){
   width: 100px !important;
@media only screen and (max-width: 360px){
   width: 65px !important;

But in even smaller screens it still appears in the same way. We can’t show the search bar on small screens because the screen size is not enough to show the search bar.
So we wrote another media query to hide all the elements of search component in small screens except close button. Because when we collapse the screen on search mode it hides all the search components and messagecomposer. To take it back to the chat mode we have to enable the close button on smaller screens.

@media only screen and (max-width: 300px){
   display: none !important;
     position: relative;
     top:6px  !important;

We have to define these two classes in “SearchField.react.js” file.

<IconButton className='displayNone'
                   <SearchIcon />
               <TextField  name='search'
                   className='search displayNone'
               <IconButton className='displayNone'>
                   <UpIcon />
               <IconButton className='displayNone'>
                   <DownIcon />
               <IconButton className='displayCloseNone'>
                   <ExitIcon />

Since we have “Codacy” integrated into our Github Repository we have to change Codacy rules because we used “!important” in media queries to override inline style which comes from Material-UI.
To change codacy rules we can simply login to the codacy and select the “code pattern ” button from the column left side.

It shows the list of rules that Codacy checks. And you can see the “!important” rule under CSSlint category like this.

Just uncheck it. Then codacy will not check your source code for “!important” attributes.

Configuring Codacy: Use Your Own Conventions: https://blog.codacy.com/configuring-codacy-use-your-own-conventions-9272bee5dcdb
Media queries: https://www.w3schools.com/css/css_rwd_mediaqueries.asp