Different JavaScript libraries in a single-page application (SPA)

Question

I am building a single-page application (SPA) based on jqWidgets library (it is in turn built on the top of jQuery UI).

Now I would like to use a widget-component available built on another framework (possibilities are Ext JS or jQuery UI).

I'm concerned about the possible problems with CSS compatibility; I read a lot on the topic and found about so called CSS Scope attribute. Unfortunately, I don't see any recent text on the subject, so I am not sure about its state.

Are there any other possibilities to battle this problem in a SPA? Or Workarounds?

What do you exactly worry about? That the new widget-component introduces new CSS that will override your existing CSS? Or the other way round? Do you have an actual example of what you mean by CSS compatibility - I am not sure if I use this term in the same way as you do... — Philipp, Jul 30 '13 at 20:55
FYI, in Ext 4.2+ all of the CSS is scoped to Ext components, so the css won't interfere on elements that Ext doesn't create. — Evan Trimboli, Jul 31 '13 at 12:10

Fergus In London · Answer 1 · 2013-07-31T12:05:36.227

If I understand correctly and you're concerned about (what essentially amounts too) conflicts with the CSS, then including your own custom stylesheets after the library ones is the best starting point; as @rthor has pointed out.

However this may not solve every issue, purely because it also depends on the specificity of the CSS selectors. There's a good article here on CSS specificity - which should also enable you to effectively combat any CSS conflicts that arise.

Now scope? That's a different subject, and one that's a little more confusing - purely because of (surprise surprise) browser implementations differ. You can just a polyfill for older browsers but that's not great. It's purely a HTML5 feature it seems Unless you're talking about the :scope psuedo-selector.. which is working draft for CSS Selectors 4

I'm sure some front-end wiz will be able to give you low down specifically regarding scope, as I expect my solution leaves a little bit to be desired. You could always make use of container elements (gasp.. I know, not ideal.) and ensure all styles specifically target children of the a container element.

Essentially..

<div id="widgetA" class="scope"> <!-- So this is our 'scope' -->
  <div id="bla bla">.....</div>
</div>

By ensuring all your CSS selectors begin with the container element:

div#widgetA{ /* We essentially get a scoped namespace */ }

However that comes with nasties such as non-semantic mark-up and overly specific selectors which are bad for performance. However, it has legacy support and is quick'n'easy.. albeit a bit of a hack. If you use something like Sass/Less you could even quickly wrap the whole libraries CSS file in a div.widget{ } rule and compile it; giving scope (albeit with the above drawbacks).

Alternatively, from a javascript view - if you target specific elements (and only those elements), I can't see too many issues arising from libraries applying their own styling - as the libraries shouldn't really be tampering with other elements.

Good luck

score 0 · Answer 2 · answered Jul 31 '13 at 10:21

Just be sure to add your own styles after the library ones and then you should be quite safe. If you encounter some strange bugs, just remove those particular CSS rules and apply them on different classes.

I believe that most bugs will be directly related to box-sizing, positioning, margin/padding and sizing.

Cheers!

score 0 · Answer 3 · edited May 23 '17 at 10:31

I recently had to use widget of two different frameworks on one page (ExtJS and jxlib, a legacy widget library based on mootools.

I got two problems:

The first was related to box-sizing. ExtJs uses box-sizing: border-box and jxLib box-sizing: content-box. Adding this to the css was all I needed:

.jxDialog * {
    box-sizing: content-box !important;
    -moz-box-sizing: content-box !important;
    -ms-box-sizing: content-box !important;
    -webkit-box-sizing: content-box !important;
}

On the Javascript side I only had one problem and got the solution in this question. With jQuery, I cannot tell if you will run into issues or not.

Different JavaScript libraries in a single-page application (SPA)

3 Answers3