Using Hidden Attribute for Angular in Susper

In Angular, we can use the hidden attribute, to hide and show different components of the page. This blog explains what the hidden attribute is, how it works and how to use it for some common tasks.
In Susper, we used the [hidden] attribute for two kinds of tasks.

  1. To hide components of the page until all the search results load.
  2. To hide components of the page, if they were meant to appear only in particular cases (say only the first page of the search results etc).

Let us now see how we apply this in a html file.
Use the [hidden] attribute for the component, to specify a flag variable responsible for hiding it.
When this variable is set to true or 1, the component is hidden otherwise it is shown.
Here is an example of how the [hidden] attribute is used:

<app-infobox [hidden]=”hidefooter class=“infobox col-md-4” *ngIf=“Display(‘all’)”></app-infobox>

Note that [hidden] in a way simply sets the css of the component as { display: none }, whereas in *ngIf, the component is not loaded in the DOM.
So, in this case unless Display(‘all’) returns true the component is not even loaded to the DOM but if [hidden] is set to true, then the component is still present, only not displayed.
In the typescript files, here is how the two tasks are performed:
To hide components of the page, until all the search results load.

this.querychange$ = store.select(fromRoot.getquery);
this.querychange$.subscribe(res => {
this.hidefooter = 1;

this.responseTime$ = store.select(fromRoot.getResponseTime);
this.responseTime$.subscribe(responsetime => {
this.hidefooter = 0;

The component is hidden when the query request is just sent. It is then kept hidden until the results for the previously sent query are available.

2. To hide components of the page, if they were meant to appear only in particular cases.
For example, if you wish to show a component like Autocorrect only when you are on the first page of the search results, here is how you can do it:

if (this.presentPage === 1) {
this.hideAutoCorrect = 0;
} else {
this.hideAutoCorrect = 1;
}

This should hopefully give you a good idea on how to use the hidden attribute. These resources can be referred to for more information.

Implementing Themes in Angular JS for Susper

Adding themes to any website, makes it more interesting to use, and also helps customize the website according to personal preferences. This blog deals with how we implemented themes in Susper.
Susper offers the following themes

  • Default
  • Dark
  • Basic
  • Contrast
  • Terminal

This is how some of the themes look
Dark:

Contrast:  
Terminal:
Lets go through a step by step guide how to implement this:

  1. Add a Themes service  (In app/src/theme.service.ts in Susper)

Here is the code snippet:

import { Injectable } from ‘@angular/core’;

@Injectable()
export class ThemeService {

public titleColor: string;
public linkColor: string;
public descriptionColor: string;
public backgroundColor: string;

constructor() { }

}

  1.  Create a component for themes, and define functions for various themes in the .ts file.(src/app/theme/theme.component.ts in Susper)

Here is the example code:

import { Component, OnInit } from ‘@angular/core’;
import { ThemeService } from ‘../theme.service’;@Component({
selector: ‘app-theme’,
templateUrl: ‘./theme.component.html’,
styleUrls: [‘./theme.component.css’]
})
export class ThemeComponent implements OnInit {constructor(
private themeService: ThemeService
) { }ngOnInit() {
}darkTheme() {
this.themeService.backgroundColor = ‘#FFFFFF’;
this.themeService.titleColor = ‘#050404’;
this.themeService.linkColor = ‘#7E716E’;
this.themeService.descriptionColor = ‘#494443’;
}

defaultTheme() {
this.themeService.backgroundColor = ‘#FFFFFF’;
this.themeService.titleColor = ‘#1a0dab’;
this.themeService.linkColor = ‘#006621’;
this.themeService.descriptionColor = ‘#545454’;
}

basicTheme() {
this.themeService.backgroundColor = ‘#FFFFFF’;
this.themeService.titleColor = ‘#1a0dab’;
this.themeService.linkColor = ‘#494443’;
this.themeService.descriptionColor = ‘#7E716E’;
}

In the above code, the first few lines  include the constructor, which defines the theme service, and include a default function that runs as soon as the page is initialized.

We then see three kinds of themes implemented, dark, default and contrast. Let us examine the darkTheme:

darkTheme() {
this.themeService.backgroundColor = ‘#FFFFFF’;
this.themeService.titleColor = ‘#050404’;
this.themeService.linkColor = ‘#7E716E’;
this.themeService.descriptionColor = ‘#494443’;
}
  • The first line sets the background color of the screen(to white).
  • The second line is used to set the color of all the titles of the search results
  • The third line is used to set the link/url color
  • The fourth line sets the description color
    1.   Link the appropriate attributes in your html pages, using [style.’css-attribute’]

(src/app/results/results.component.html in Susper)

Following this example, you can link different parts of the html file to the attributes in your theme service and you are done!
If implementing this in a project like Susper, a few points of caution:

  • Make sure you write your spec.ts file well, and add your component for proper compilation and testing.
  • Do not forget to import the service into any component before you use it in its html files.

Resources 

Creating nested routes in Open Event Front-end and Navigating them with Tabs via semantic UI – Ember Integration

Semantic UI is a modern development framework which helps build responsive and aesthetically beautiful layouts. While it is a really powerful framework in itself, it additionally offers seamless integrations with some of the other open source frameworks including ember js.

Open Event Front-end is a project of FOSSASIA organisation, which was created with the aim of decoupling the front end and the back end for the open event orga server. It is primarily based on ember JS and uses semantic UI for it’s UI.

Here we will be making a nested route /events/ with /events/live/, events/draft, events/past , events/import as it’s subroutes.

To get started with it, we simply use the ember CLI to generate the routes

$ ember generate route events

Then we go on to generate the successive sub routes as follows

$ ember generate route events/live
$ ember generate route events/past
$ ember generate route events/draft
$ ember generate route events/import

The router.js file should be looking like this now.

this.route('events', function() {
    this.route('live');
    this.route('draft');
    this.route('past');
    this.route('import');
  });

This means that our routes and sub routes are in place. Since we used the ember CLI to generate these routes, the template files for them would have generated automatically. Now these routes exist and we need to write the data in the templates of these routes which will get displayed to the end user.

Since the routes are nested, the content of the parent route can be made available to all the children routes via the outlet in ember js.

Next, we go to the template file of events/ route which is at templates/events.hbs And write the following code to create a menu and use ember integration of semantic UI link-to to link the tabs of the menu with the corresponding correct route. It will take care of selecting the appropriate data for the corresponding route and display it in the correct tab via the outlet

<.div class="row">
  <.div class="sixteen wide column">
    <.div class="ui fluid pointing secondary menu">
      {{#link-to 'events.live' class='item'}}
        {{t 'Live'}}
      {{/link-to}}
      {{#link-to 'events.draft' class='item'}}
        {{t 'Draft'}}
      {{/link-to}}
      {{#link-to 'events.past' class='item'}}
        {{t 'Past'}}
      {{/link-to}}
      {{#link-to 'events.import' class='item'}}
        {{t 'Import'}}
      {{/link-to}}
    <./div>
  <./div>
<./div>
<.div class="ui segment">
  {{outlet}}
<./div>

So finally, we start filling in the data for each of these routes. Let’s fill some dummy data at templates/events/live.hbs

<.div class="row">
  <.div class="sixteen wide column">
    <.table class="ui tablet stackable very basic table">
      <.thead>
        <.tr>
          <.th>{{t 'Name'}}<./th>
          <.th>{{t 'Date'}}<./th>
          <.th>{{t 'Roles'}}<./th>
          <.th>{{t 'Sessions'}}<./th>
          <.th>{{t 'Speakers'}}<./th>
          <.th>{{t 'Tickets'}}<./th>
          <.th>{{t 'Public URL'}}<./th>
          <.th><./th>
        <./tr>
      <./thead>
      <.tbody>
        <.tr>
          <.td>
            <.div class="ui header weight-400">
              <.img src="http://placehold.it/200x200" alt="Event logo" class="ui image">
              Sample Event
            <./div>
          <./td>
          <.td>
            March 18, 2016 - 09:30 AM
            <.br>(to)<.br>
            March 20, 2016 - 05:30 PM
          <./td>
          <.td>
            <.div class="ui ordered list">
              <.div class="item">[email protected] ({{t 'Organizer'}})<./div>
              <.div class="item">[email protected] ({{t 'Manager'}})<./div>
            <./div>
          <./td>
          <.td>
            <.div class="ui list">
              <.div class="item">{{t 'Drafts'}}: 0<./div>
              <.div class="item">{{t 'Submitted'}}: 0<./div>
              <.div class="item">{{t 'Accepted'}}: 0<./div>
              <.div class="item">{{t 'Confirmed'}}: 0<./div>
              <.div class="item">{{t 'Pending'}}: 0<./div>
              <.div class="item">{{t 'Rejected'}}: 0<./div>
            <./div>
          <./td>
          <.td>
            2
          <./td>
          <.td>
            <.div class="ui bulleted list">
              <.div class="item">{{t 'Premium'}} (12/100)<./div>
              <.div class="item">{{t 'VIP'}} (10/15)<./div>
              <.div class="item">{{t 'Normal'}} (100/200)<./div>
              <.div class="item">{{t 'Free'}} (100/500)<./div>
            <./div>
          <./td>
          <.td>
            <.div class="ui link list">
              <.a class="item" target="_blank" rel="noopener" href="http://nextgen.eventyay.com/e/ecc2001a">
                http://nextgen.eventyay.com/e/ecc2001a
              <./a>
            <./div>
          <./td>
          <.td class="center aligned">
            <.div class="ui vertical compact basic buttons">
              {{#ui-popup content=(t 'Edit event details') class='ui icon button'}}
                <.i class="edit icon"><./i>
              {{/ui-popup}}
              {{#ui-popup content=(t 'View event details') class='ui icon button'}}
                <.i class="unhide icon"><./i>
              {{/ui-popup}}
              {{#ui-popup content=(t 'Delete event') class='ui icon button'}}
                <.i class="trash outline icon"><./i>
              {{/ui-popup}}
            <./div>
          <./td>
        <./tr>
      <./tbody>
    <./table>
  <./div>
<./div>

 Similarly we can fill the required data for each of the routes.And this is it, our nested route is ready. Here is a screenshot what you might expect.

Screenshot highlighting the tabs

Resources