Creating a Javascript load more plugin part 2 – Searching2 min read

In the first part Creating a Javascript load more plugin part 1 , we have created a javascript plugin which loads data from an API page. Let’s build upon on it.

Today we are going to add search option to our plugin, children ? .

Objectives ?

  • Add search bar to the page.
  • On input on search bar, load in relevant content from the API.
  • The API should take in a search parameter and provide relevant results.

As of now we are sending two parameters to the API – start and count. We would add one more q for sending the search query.

For learning how add searching option at the server end, please refer this tutorial from Codecourse – Basic PHP & MySQL Searching.

It uses PHP and MYSQL but you get the idea ? .

Demo page – Javascript load more plugin – search added.

We have to add one more line to our previous HTML code to include the search bar.

<input type="search" autocomplete="off" class="finder" />

We can add this anywhere inside our main container. Only condition is that it should have a class of finder, so that our plugin can identify it.

For styling HTML forms and form elements view this tutorial – Styling HTML Forms .

Updating the Plugin

Now let’s upgrade our plugin. First we would find the search bar.

//Search bar
this.finder = this.elem.getElementsByClassName('finder').length ? this.elem.getElementsByClassName('finder')[0] : false;

If you are not able to follow, please go through part one of this series.

Now, inside our lmore.load method we would append the search term to the GET query string.

//create query string with
//start and count variables
var qs = this.source + '?lmore_start=' + this.start + '&lmore_count=' + this.count;

//Send search query if search bar is available
qs += this.finder ? '&q=' + this.finder.value.trim() : '';
this.http.open('GET', qs);
this.http.send();

Let’s add and event listener to the search bar so that, data can be loaded while searching.

We could load data on any event, but I prefer the on-input event because it gives an instant search effect.

I don’t like search bars that have a button which has to be clicked to search. We are in 2016, common guys ( who make me click a button to search ? )  ?.

We could even pass the event, as input for the plugin.

if (this.finder) {
  this.finder.addEventListener('input', function() {
    this.load();
  }.bind(this));
}

You could also use this plugin to give search suggestions like google. Maybe we could use the plugin two times, one for suggestions and one for showing search results.

Comment below if you want to see this plugin give you search suggestions.

Javascript load more plugin6 min read

When searching the internet for a Javascript load more plugin, I came across a Jquery load more plugin tutorial in this youtube channel – Codecourse.

I highly recommend that the reader watch the Codecourse (formerly PHPacademy) tutorial and subscribe to their channel before continuing.

Link to the tutorial – Load More jQuery Plugin.

The tutorial was a really good and the plugin was very useful. But, with the aim of getting better at javascript and programming in general I tried to customize it.

So I decided to redo it in pure javascript. Here is how it went.

Demo link – Javascript load more plugin demo.

Please refer the above tutorial for creating a server side JSON API. The API would look like this Load more JSON API.

Now let’s get started with our plugin.

How to use?

<script src="lmore.js"</script>
<script>
  var itemload=new lmore({elem:cont,source:'json-api-load-more-plugin/',count:3});
</script>

Parameters

  • elem: The main container.
  • source: JSON API page.
  • count: Number of results to load per request.

HTML

The plugin requires an HTML template to work with and the template would look like this.

<div id="cont">
  <span class="rescont" >
    <div id="ent_cont" class="items" >
      <div class="item" >
        <p data-field="id" class="hide" ></p>
        <h2 data-field="title" ></h2>
        <p data-field="description" ></p>
      </div>
    </div>
  </span>
  <div id="no_result" class="nores" >No results to display.</div>
  <button id="load_more" class="load_more" >Load more</button>
</div>

Elements included are

  • #cont – Main Container.
  • .rescont – Container where results have to be loaded.
  • .items – Container for .item
  • .item – Individual data container which would be cloned with each result set.
  • [data-field] – The value of this attribute would be matched with the keys in the JSON object and corresponding values would be filled.
  • .nores – The element to be shown when there are no results. .rescont would be hidden and .nores would be shown if there are no results.
  • .load_more – Button which on click would load more results.

JAVASCRIPT

The plugin would take 3 inputs as given in the usage section.

It would have two main functions

  1. load – A function to load data from the JSON API page using ajax.
  2. append – A function to append the loaded data to the DOM.

The plugin

Wrapper
var lmore = function(options) {
  this.append = function() {

  }
  this.load = function() {

  }
}
Now we have to set the necessary properties.
//Default options
this.def_option = {
  elem: NaN,
  source: NaN,
  count: 3
};

//set the properties
if (options) {
  for (key in options) {
    if (this.def_option.hasOwnProperty(key)) {
      this[key] = options[key];
    }
  }
}

//Http request variable
this.http = 0;

//Starting point
this.start = 1;

//Load more button
this.load_more = false;

//Whether it load more button was clicked or not
this.is_load_more = false;
Getting load more button and saving it and it’s display property
  //set load more button
  if (this.elem.getElementsByClassName('load_more')[0]) {
    this.load_more = this.elem.getElementsByClassName('load_more')[0];
    this.load_more_display = this.load_more.style.display;
    this.load_more.style.display = 'none';
  }
Cloning .item element and removing it from the DOM.
//Clone .item and remove it from DOM
this.items = this.elem.getElementsByClassName('items')[0];
this.itemo = this.items.getElementsByClassName('item')[0];
this.item = this.itemo.cloneNode(true);
this.items.removeChild(this.itemo);
this.nores = this.elem.getElementsByClassName('nores')[0];
this.rescont = this.elem.getElementsByClassName('rescont')[0];
this.resdis = this.rescont.style.display;

//function to remove .item from DOM
this.remove = function() {
  while (this.items.firstChild) {
    this.items.removeChild(this.items.firstChild);
  }
}
The load function
this.load = function() {
  //Check if load more button was clicked
  if (!this.is_load_more) {
    this.start = 1;
    this.remove();
  } else {
    this.start += this.count;
  }


  this.is_load_more = false;

  //Abort pending ajax calls if any
  if (this.http != 0) {
    this.http.abort();
  }

  //Ajax request
  this.http = new XMLHttpRequest();
  this.http.onreadystatechange = function() {
    if (this.http.readyState == 4 && this.http.status == 200) {
      res = JSON.parse(this.http.responseText);
      resp = res.items;

      //If last result hide load more button else show
      if (this.load_more) {
        if (!res.last) {
          this.load_more.style.display = this.load_more_display;
        } else {
          this.load_more.style.display = 'none';
        }
      }

      //Check if there are results
      //If not the no results text is shown
      if (undefined !== resp && resp != null && resp.length) {
        //Loop through each result set
        //and pass it to append function
        for (var i = 0, q = resp.length; i < q; i++) {
          this.append(resp[i]);
        }
        this.nores.style.display = 'none';
        this.rescont.style.display = this.resdis;
      } else {
        this.nores.style.display = 'block';
        this.rescont.style.display = 'none';
      }
    }
  }.bind(this);
  //.bind is used so that 'this' is set
  //to lmore object

  //create query string with 
  //start and count variables
  var qs = this.source + '?lmore_start=' + this.start + '&lmore_count=' + this.count;
  this.http.open('GET', qs);
  this.http.send();
};
The append function
//Append API data to DOM
this.append = function(value) {

  //Create a clone of the .item 
  var clone = this.item.cloneNode(true);

  //select all elements in .item
  //with data-field attribute
  var subs = clone.querySelectorAll('[data-field]');

  //loop through API result
  for (name in value) {
    if (value.hasOwnProperty(name)) {

      //loop through elements
      //with data-field attr
      for (var i = 0, q = subs.length; i < q; i++) {

        //id attr = key of object
        //set value
        if (subs[i].getAttribute('data-field') == name) {
          var ptext = value[name];
          var text = document.createTextNode(ptext);
          this.set_val(subs[i], ptext);
        }
      }
    }
  }

  //append the cloned element
  //to .items
  this.items.appendChild(clone);
};
Function to set value of any element
//Function to set value of any element
//params el - element to set value to
//val - the value to be set
this.set_val = function(el, val) {
  var node_type = el.nodeName.toLowerCase();
  if (node_type != 'input' && node_type != 'select' && node_type != 'textarea') {
    el.innerHTML = val;
    return true;
  }
  if (node_type == 'select' || (node_type == 'input' && el.type != 'checkbox') || node_type == 'textarea') {
    if (el.hasAttribute('multiple')) {
      this.multi_set(el, val);
      return true;
    }
    el.value = val;
    return true;
  } else if (el.type == 'checkbox') {
    el.checked = (val == '1') ? true : false;
    return true;
  }
  return false;
}

//Function to set value of select multiple
this.multi_set = function(sel, values) {
  var vals = Array.isArray(values) ? values : String(values).split(',');
  var opt;
  for (var i = 0, len = sel.options.length; i < len; i++) {
    opt = sel.options[i];
    opt.selected = false;
    for (var x = 0, q = vals.length; x < q; x++) {
      if (opt.value == vals[x]) {
        opt.selected = true;
      }
    }
  }
}
Initial loading

Also setting event listener on load more button to load data on click

//Load first set of data on page load
this.load('');

//The load more button on click would load
//the nextr set of results
if (this.load_more) {
  this.load_more.addEventListener('click', function() {

    //is_load_more is set to true
    //so that start is not reset
    this.is_load_more = true;
    this.load();
  }.bind(this));
}

And finally the plugin is complete ????.

Download link – lmore.js.

Leave your suggestions below.

My take on Reliance Jio4 min read

Reliance Jio offers unlimited free calls and 4G LTE data till December 2016. I have recently got the Jio sim card, of course to get free 4G internet ???? .

Speed

This Economic times article says Jio offers 17.34 Mbit/s down speed.

But I get about 4 – 7 Mbps download speed on average when in full range. Speed measured with fast.com

I was very happy about this until I searched the internet for 4G LTE speeds.

Data speeds of LTE (Theoretical)
LTE
Peak download 100 Mbit/s
Peak upload 50 Mbit/s

Stolen from – Wikipedia.org

OK there is nothing here to be unhappy about, everybody knows that’s not going to happen. But let’s look at the average speeds in other countries.

Average speeds of 4G in other countries – 
UK  16 – 25 Mbit/s
USA 9 – 16 Mbit/s

Stolen from – Opensignal.com

Hmmm… ????

Maybe Opensignal results from india would also show similar results and the speed may vary in different parts of India.

So the question is am I happy with the speeds that I get?

A – I am, very much.

Why Jio calls are free?

The answer is they are not. Jio offers unlimited calls for a fixed charge and does not charge you by duration of the call like other providers.

For example if we look at their 149 plan, it offers 400 MB of 4G data and unlimited Local/STD calls for a period of 28 days from charging.

After 28 days if you do not recharge, the calls are no more free.

But when compared to other providers who charge separately and too much for data, calls and sms, the Jio offer looks pretty good.

How does Jio calls work?

Jio uses VoLTE standard for making calls. Unlike other providers Jio only has 4G LTE networks plus their wifi network as given in their website.

So calls pass through the LTE network following a protocol known as VoLTE (Voice over LTE). But other providers use 2G network with GSM protocol to make voice calls.

Essentially the voice is broken down and send as data packets.

Any LTE enabled phone can can make voice calls with Jio. But the phone must have the necessary software that supports the VoLTE protocol. Your phone may already have this or you can get it from doing an OS upgrade.

Jio provides the Jio voice app for phones that do not support VoLTE.

Does Reliance sent our personal data to ad networks?

Anonymous India Claims That Reliance Jio Is Sharing Call Data With Advertisers.

The above article says that Anonymous India, a hacker group claimed Jio apps are sending user call data to servers in US and Singapore and also to an ad network.

The group has also made more claims and Reliance has answered the concerns.

Anonymous post – Told truth with facts about Reliance Jio Chat app, targeted by Reliance Media Director.

Reliance reply – A statement by Reliance Jio Infocomm Ltd.

Any provider can view or sell user data unless it is encrypted at a higher level because it just passes through their gateways. But it would be illegal to do so without mentioning it in their terms and conditions.

 But the privacy policy in Jio website says

Improving your experience while using our services by presenting advertising, products and offers tailored to you;

And in the collection of information section it says

Usage logs/Server logs/Cookies which may contain details of your personal or sensitive personal information.

Conclusion : Hmmm… ????

Unlimited at night

No, Jio does not offer unlimited internet through out the night. It’s just from 2 am to 5 am.  We get unlimited internet for 3 hours a day, but at that part of the day when we least need it. Thank you Mr. Ambani ????.

 Rates

And finally Jio offers its services at the cheapest rates India has ever seen. So what are you waiting for go get it, at least when everything is free. Prove your Indian-ness ???? .