Categories
Dev JavaScript Optimising

How to write modern JS

So you’re learning JavaScript (JS), cool. Putting all this effort in, you’ll want to be learning the modern usage of the language right? Time to get strict.

“use strict” is something I recently stumbled across, and it seems like a really important thing to be using. So much so that I’m a bit surprised it hasn’t been mentioned in the course I’m doing. As it turns out, JS is full of legacy thinking. In an effort to keep new versions of the language compatible with older versions, much of this legacy thinking was/is retained. Obviously this limits JavaScripts ability to overcome its past and improve as time goes on.

Evidently, in 2009 a decision was made to start to modernise JS with the release of ECMAScript 5 (ES5). This meant breaking compatibility with older version of JS if you decided that was what you wanted to do. This is where “use strict” comes in. To enable this “modernisation” you include “use strict” at the top of your JS files like this:

"use strict";
// code below this will be implemented the modern way
...

Since it’s been 10 years since that decision was made, all modern browsers now support ES5. So unless you need to support browsers before the dawn of IE10 then you should be turning strict mode on for all of your JS development.

This of course begs the question, why? Well, aside from staying current with the language, there are also a number of practical benefits:

  1. Modern JS throws errors on things that where previously ignored. This helps you write better, more secure code
  2. It can improve the performance of your code, sometime significantly. Sometimes the code itself is identical and you just get a free performance boost, nice!
  3. It prevents some syntax being use that future version of the language are likely to use. AKA it future proofs your code

So from here on in, I’m going to be using strict mode exclusively and only avoid it when a situation presents itself that I can’t.

As always MDN is a good source of information on both strict and sloppy mode. Now go forth and write strict code!

Categories
Dev Process Tools

Pastebot

The more time I spend coding the more time I find myself researching solutions to workflow problems I’ve never had before. Copy and paste is a good example of this.

Sharpening my coding skills I find myself copying and pasting a lot more than normal. Maybe a better way to say it is coping and pasting in specific ways a lot more. For example, when I’m writing CSS I tend to copy and paste a small set of different colour codes over and over. Another example would be copying lists of items from a document one at a time to populate a list in an HTML document.

I had never considered that there might be a better way of doing these things until I stumbled on Pastebot. Pastebot is like copying and pasting on steroids. At a basic level, it keeps a history of everything you copy and paste. Even this simple function makes it incredibly useful when coding. Need to paste that colour code you copied 30 mins ago? Bam there it is in your clipboard history.

Once you’ve got used to having clipboard history you’ll never go back to your old ways. As a developer though that’s not even the best part. Where Pastebot really shines is its filters. Want to copy of a list of items then paste them as an HTML list? Want to copy some text and pasted it wrapped it in <p> tags? Pastebot can take care of all of that for you.

Do yourself a favour and at the very least investigate a clipboard manager, and if you’re on a Mac make sure you try Pastebot. It really is worth your time.

Categories
Dev JavaScript Tools

on() click()

Today I learnt the different between the on(“click”) and click() methods in jQuery.

click() only adds listeners for existing elements, so it will completely ignore any dynamically added items. So in the example below only the <li> declared in the html file will be clickable. All of the new <li> elements added to the todo list won’t be clickable:

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title></title>
  <link rel="stylesheet" type="text/css" media="screen" href="assets/css/style.css" />
  <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.2/css/all.css" integrity="sha384-fnmOCqbTlWIlj8LyTjo7mOUStjsKC4pOpQbqyi7RrhN7udi9RwhKkMHpvLbHG9Sr"
    crossorigin="anonymous">
  <script src="https://code.jquery.com/jquery-3.3.1.min.js" integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8="
    crossorigin="anonymous"></script>
</head>

<body>
  <div id="container">
    <h1>To-Do List</h1>
    <input type="text" name="" id="">
    <ul>
      <li><span>X</span> Go to potions class</li>
      <li><span>X</span> Buy a new broom</li>
      <li><span>X</span> Visit Hagrid</li>
    </ul>
  </div>
  <script type="text/javascript" src="assets/js/script.js" charset="utf-8"></script>
</body>

</html>
// check off specific todos by clicking
$( "li" ).click( function () {
  $( this ).toggleClass( "completed" );
} );

// click on x to delete todo item
$( "span" ).click( function ( event ) {
  $( this ).parent().fadeOut( 300, function () {
    $( this ).remove();
  } );
  event.stopPropagation();
} );

// add new item to todo list on keypress
$( "input[type='text']" ).keypress( function ( event ) {
  if ( event.which === 13 ) {
    var todoItem = $( this ).val();
    $( this ).val( "" );
    $( "ul" ).append( "<li><span>X</span> " + todoItem + "</li>" );
  }
} );

To get around this, instead of using click() we use on(“click”). Unlike click() on(“click”) will add listeners for all potential future elements on the page. This makes all the dynamic content, like the new items in our todo list app, work flawlessly. So the updated code would look like this:

// check off specific todos by clicking
$( "ul" ).on( "click", "li", function () {
  $( this ).toggleClass( "completed" );
} );

// click on x to delete todo item
$( "ul" ).on( "click", "span", function ( event ) {
  $( this ).parent().fadeOut( 300, function () {
    $( this ).remove();
  } );
  event.stopPropagation();
} );

// add new item to todo list on keypress
$( "input[type='text']" ).keypress( function ( event ) {
  if ( event.which === 13 ) {
    var todoItem = $( this ).val();
    $( this ).val( "" );
    $( "ul" ).append( "<li><span>X</span> " + todoItem + "</li>" );
  }
} );

jQuery has some excellent documentation. So if you need to drill into the specifics of any particular method (like on() or click()) be sure to RTFM.

Categories
Dev JavaScript

Pigs in namespaaaace

When you’re working on a JavaScript (JS) app you’ll create loads of functions and variables. By default in JS, there is no namespacing so everything you declare is effectively in the global namespace. This can lead to issues where two or more functions or variables can easily be called the same thing and create conflicts. Take this example:

function pigs() {
  console.log("Pigs in space");
}

function pigsDance() {
  console.log("Pigs dancing in space");
}

function pigs() {
  console.log("Pigs in Mexico");
}

pigs();

The output of this will be “Pigs in Mexico”. To avoid collisions like this we can use an object to create a namespace. So reworking our above example:

var space(){
  function pigs() {
    console.log("Pigs in space");
  }
  function pigsDance() {
    console.log("Pigs dancing in space");
  }
}

function pigs() {
  console.log("Pigs in Mexico");
}

space.pigs();

This will return “Pigs in space”. By creating the object and making “pigs()” and “pigsDancing()” properties of that object, we isolate them from the global namespace that “pigs()” lives in.

This way, when we need our pigs in space, that’s exactly where they will be.

Categories
Dev Tools

Atom snippets

One of the things I love about modern text editors is code snippets. Coding tends to involve repetition, code snippets can really help cut down on needless typing.

I group all my code snippets by prefixing them with “my”. That way to view all my snippets I just start typing “my” and Atom shows all my snippets for the specific file type I’m currently working on.

Some simple examples I use quite often are:

myHTML – My own HTML boilerplate

<!DOCTYPE html>
  <html lang="en">

  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title></title>
    <link rel="stylesheet" type="text/css" media="screen" href="assets/css/style.css" />
  </head>

  <body>
  
  <script type="text/javascript" src="assets/js/script.js" charset="utf-8"></script>
  </body>

  </html>

myjQuery – Inserts jQuery using their CDN

<script src="https://code.jquery.com/jquery-3.3.1.min.js"   integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8="   crossorigin="anonymous"></script>

myFontAwesome – Inserts font awesome using their CDN

<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.2/css/all.css" integrity="sha384-fnmOCqbTlWIlj8LyTjo7mOUStjsKC4pOpQbqyi7RrhN7udi9RwhKkMHpvLbHG9Sr" crossorigin="anonymous">

myLog – inserts a console.log() to help debug my JavaScript

console.log()

Getting all this working in Atom is a fairly easy affair. I found the below video by Hitesh Choudhary super useful.

Categories
Dev JavaScript

Selection

One thing I notice about jQuery is how it simplifies common tasks. A good example is something you do all the time with JavaScript, select DOM elements. In JavaScript selecting all li elements would look something like this:

document.querySelectorAll( "li" );

The same selection using jQuery is like this:

$("li")

At this stage of my learning, I can’t say I see the above as a major advantage. Yes, it’s shorter but you could argue it’s also less descriptive for the reader. Brevity isn’t always a net win in code. This is especially true when tools like Emmet and other text editor tricks auto-complete a lot of code. So it’s not 100% clear to me what the advantage is.

It will be interesting as my jQuery knowledge grows if my feelings toward it change. At this early stage, I can’t help feeling sceptical. Especially when I keep hearing about frameworks like Angular and React. I guess we will see.

Categories
Dev

Emmet!

Whatever your text editor of choice (I just can’t quit you Atom) there is a wide range of plugins to enhance its capabilities. One such plugin that I use constantly is Emmet.

Emmet can be used for a number of things, but where it really shines is speeding up my HTML production. Emmet uses a CSS like syntax to quickly produce common HTML code.

The most common situations I find myself using it is when I initially create an HTML document. To do this you just type “!” and hit tab. The result will be:

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>

<body>

</body>

</html>

Perhaps most useful of all is adding repetitive blocks of HTML like lists. Just type “ul>li.lego{Awesome}*10” then hit tab and you’ll get:

<ul>
  <li class="lego">Awesome</li>
  <li class="lego">Awesome</li>
  <li class="lego">Awesome</li>
  <li class="lego">Awesome</li>
  <li class="lego">Awesome</li>
  <li class="lego">Awesome</li>
  <li class="lego">Awesome</li>
  <li class="lego">Awesome</li>
  <li class="lego">Awesome</li>
  <li class="lego">Awesome</li>
</ul>

Or you can get super fancy and nest all sorts of things. Give something like this a go. Type “div.awesome>(header>ul>li.item$*5>a{Awesome thing $})+footer>p{Awesome}” and hit tab. Boom you get:

<div class="awesome">
  <header>
    <ul>
      <li class="item1"><a href="">Awesome thing 1</a></li>
      <li class="item2"><a href="">Awesome thing 2</a></li>
      <li class="item3"><a href="">Awesome thing 3</a></li>
      <li class="item4"><a href="">Awesome thing 4</a></li>
      <li class="item5"><a href="">Awesome thing 5</a></li>
    </ul>
  </header>
  <footer>
    <p>Awesome</p>
  </footer>
</div>

As you can see, once you learn the basic structure, everything is awesome with Emmet.

Categories
Geekpulp

jQuery

What is jQuery?

jQuery is a JavaScript library designed to simplify front end web development. It is the most widely deployed JavaScript library by an insanely large margin.

Why use jQuery

There are quite a few reasons you’d want to use jQuery, or a library like it, in your project rather than vanilla JavaScript. Here are a few examples.

Ease of use

JavaScript can be a handful, jQuery can be far cleaner and more concise than the equivalent in vanilla JavaScript. Take a look at these two examples of a fade in effect:

JavaScript Fade In

function fadeIn(element) {
  element.style.opacity = 0;
  var last = +new Date();
  var tick = function() {
    element.style.opacity = +element.style.opacity + (new Date() - last) / 400;     
    last = +new Date();
    if (+element.style.opacity < 1) {
      (window.requestAnimationFrame && 
      requestAnimationFrame(tick)) || setTimeout(tick, 16);
    }   
  };
  tick();
}
fadeIn(element);

jQuery Fade In

$(element).fadeIn();

Cross browser support

Cross-browser support is one of the most difficult things about web development. jQuery normalises this so you don’t have to worry about different browsers as much.

This reason becomes less true with time. However, If you need to support older browsers, particularly anything older than IE8 then you should seriously consider jQuery.

Lots of people use jQuery

It might seem like a silly reason to use something just because loads of others are using it too. Having said that there are some real benefits to that thinking. In particular, there are plenty of resources available to help you learn and use jQuery. So if you need examples of how to do something you should have no problem finding them.

Even if you’re already a skilled developer, the practice of coding is continuous learning. So it’s always good to have a strong community around the area in which you work.

Why not use jQuery?

Based on the above you’d think jQuery would be a no brainer, and in many situations that’s true. However there are plenty of situations where it isn’t the best option, here’s why.

You can do everything without it

There is nothing in jQuery you can’t do in vanilla JavaScript. So depending on your project adding jQuery to the mix may actually be creating an unnecessary dependency. If you’re not using many of jQuery’s capabilities in your app, it pay’s to consider alternatives.

jQuery contains hundreds of methods that on many applications you’ll never use. There’s no sense in bundling all that in if you’re only using a small part of it.

People are moving away from jQuery

This one is a little contentious as depending on who you’re talking to. For a few years now there are signs that people may or may not be moving away from jQuery. Regardless, if new jQuery based projects are in decline there is such a huge existing usage of the library it still pays to learn it.

Categories
Dev Process

We’ve all got issues

Since I’ve been learning JavaScript I’ve been making an effort to do things as if I was working with others. The idea being that any project of meaning is very likely a collaborative one.

To my mind understanding how to effectively work with others on a coding project is as important as the coding itself. Also understanding how people work is always good when managing people is part of your professional life.

To that end, since I’ve recently created an “app” and put it on GitHub, the obvious next step was to record any issues with the app. So far there are three, but I suspect there are plenty more.

  1. The interface needs styling
  2. What constitutes victory isn’t clear
  3. Max score change doesn’t affect victory formatting

Over time I aim to chip away at these and any other reported issues. Of course being open-source, it’s entirely possible others may do the same. Which would no doubt teach me something too…

Categories
Dev Projects

I made a thing – Score keeper

I’ve been doing a web development course for a few months and today I made my first thing that actually does something. Nothing amazing mind you, but it’s a start.

Do you ever have the need to keep score in a best 2 out of 3 kind of way? Me neither, but here’s a web app that does it regardless  🙂

At some stage, I’ll pop it on a web server and make it live for anyone to use. For now, if you’re interested in the code, take a look at the GitHub repo or you can download it directly.

Update: The app’s now live. Give it a try.