Refactoring Autocomplete JS & CSS

We still have work to do to get the new.html.twig template working:

... lines 1 - 2
{% block javascripts %}
... lines 4 - 5
<script src="https://cdn.jsdelivr.net/autocomplete.js/0/autocomplete.jquery.min.js"></script>
<script src="{{ asset('js/algolia-autocomplete.js') }}"></script>
... line 8
{% endblock %}
... lines 10 - 25

we have a script tag for this external autocomplete library and one for our own public/js/algolia-autocomplete.js file... which is our last JavaScript file in the public/ directory! Woo!

$(document).ready(function() {
$('.js-user-autocomplete').each(function() {
var autocompleteUrl = $(this).data('autocomplete-url');
$(this).autocomplete({hint: false}, [
{
source: function(query, cb) {
$.ajax({
url: autocompleteUrl+'?query='+query
}).then(function(data) {
cb(data.users);
});
},
displayKey: 'email',
debounce: 500 // only request every 1/2 second
}
])
});
});

This holds code that adds auto-completion... on this author box... which, yes, is totally broken.

Installing the Autocomplete Library

To start, remove the CDN link to this autocomplete library:

... lines 1 - 2
{% block javascripts %}
... lines 4 - 5
<script src="https://cdn.jsdelivr.net/autocomplete.js/0/autocomplete.jquery.min.js"></script>
... lines 7 - 8
{% endblock %}
... lines 10 - 25

And, at your terminal, install it properly!

yarn add autocomplete.js --dev

Organizing our Autocomplete into a Component

Next, you know the drill, take the algolia-autocomplete.js file and move it into the assets/js/ directory. But I'm not going to make this a new entry point. We could do that, but really, we already have an entry file that's included on this page: admin_article_form:

... lines 1 - 2
{% block javascripts %}
... lines 4 - 7
{{ encore_entry_script_tags('admin_article_form') }}
{% endblock %}
... lines 10 - 25

So really, admin_article_form.js should probably just use the code from algolia-autocomplete.js.

So, move that file into the components/ directory... which is kind of meant for reusable modules. And... well, this isn't really written like a re-usable module yet because it just executes code instead or returning something, like a function. But, we'll work on that later.

Let's also take the algolia-autocomplete.css file and move that all the way up here into assets/css/. And just because we can, I'll make it an SCSS file!

Okay! Back in admin_article_form.js, let's bring in this code: import './components/algolia-autocomplete':

... lines 1 - 4
import './components/algolia-autocomplete';
... lines 6 - 157

We don't need an import from yet... because that file doesn't actually export anything. For the CSS: import '../css/algolia-autocomplete.scss':

... lines 1 - 4
import './components/algolia-autocomplete';
import '../css/algolia-autocomplete.scss';
... lines 7 - 157

Back in new.html.twig, the great thing is, we don't need to import this CSS file anymore or any of these script files. This is really how we want our templates to look: a single a call to {{ encore_entry_script_tags() }} and a single call to {{ encore_entry_link_tags() }}:

... lines 1 - 2
{% block javascripts %}
{{ parent() }}
{{ encore_entry_script_tags('admin_article_form') }}
{% endblock %}
{% block stylesheets %}
{{ parent() }}
{{ encore_entry_link_tags('admin_article_form') }}
{% endblock %}
... lines 14 - 22

So if we refresh right now, not surprisingly, it still won't work! And it's our favorite error!

$ is undefined

from algolia-autocomplete.js. Yes, this is the error I see when I close my eyes at night.

Using the autocomplete.js Library

Let's get to work. Of course, we are referencing $. So, import $ from 'jquery':

import $ from 'jquery';
... lines 2 - 23

We're also using the autocomplete library in here. No problem: import autocomplete from 'autocomplete.js':

import $ from 'jquery';
import autocomplete from 'autocomplete.js';
... lines 3 - 23

Wait... that's not quite right. This autocomplete.js library is a standalone JavaScript library that can be used with anything - jQuery, React, whatever. But... our existing code isn't using the "standalone" version of the library. It's using a jQuery plugin - this .autocomplete() function - that comes with that package:

... lines 1 - 3
$(document).ready(function() {
$('.js-user-autocomplete').each(function() {
... lines 6 - 7
$(this).autocomplete({hint: false}, [
... lines 9 - 19
])
});
});

So, we could refactor our code down here to use the, kind of, official way of using this library - independent of jQuery. But... that's the easy way out! Let's see if we can get this to work as a jQuery plugin.

Finding and Using the jQuery Plugin

I'll hold Command or Control and click into autocomplete.js. Then double-click the directory to zoom us there. The "main" file is this index.js at the root of the directory. But if you look in dist/, hey! autocomplete.jquery.js! That's what we were including before via the <script> tag!

So instead of importing the main file, let's import autocomplete.js/dist/autocomplete.jquery:

import $ from 'jquery';
import 'autocomplete.js/dist/autocomplete.jquery';
... lines 3 - 23

And remember, we don't use import from with jQuery plugins... because they don't return anything: they modify the jQuery object.

Ok, I think we're great and I think we're ready. Move over, refresh and... huh:

jQuery is not defined

Notice it doesn't say "$ is not defined": it says "jQuery is not defined"... and it's coming from autocomplete.jquery.js! It's coming from the third party package!

This... is tricky. Plain and simple, that file is written incorrectly. Yea, it only works if jQuery is a global variable! And in Webpack... it's not! Let's talk more about this and fix it with some black magic, next.

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