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<h1 id="obvious-javascript-injection-fallback">Obvious Javascript &#8216;Injection&#8217; Fallback</h1>
<p>2020-12-04</p>
<p>Sometimes websites and web apps might require content to be &#8220;injected&#8221; via Javascript. I should mention that I am strongly against this practice - but often this kind of thing is out of one&#8217;s hands. So, the least I can do is setup these &#8220;injections&#8221; to have proper fallbacks for users who disable JS. You would be surprised how many developers build <em>empty</em> HTML elements with the assumption they will be filled via Javascript.</p>
<h2 id="our-hypothetical-project">Our Hypothetical Project</h2>
<p>Let&#8217;s pretend that we have a total tally that pulls in the number of current users using our fake SaaS app. We would do something like this:</p>
<h3 id="html">HTML</h3>
<p>Here we create an empty <code>h2</code> tag that will update with the current number of users via js:</p>
<pre><code>&#60;main&#62;
    &#60;h2 class="total-tally"&#62;&#60;&#47;h2&#62;
&#60;&#47;main&#62;
</code></pre>
<h3 id="javascript">Javascript</h3>
<p>You&#8217;ll have to use your imagination here and assume that the <code>totalTally</code> variable pulls in the numbers dynamically via API:</p>
<pre><code>var totalTally = "273,677" &#47;* This would pull something dynamically in prod *&#47;
document.getElementsByClassName("total-tally")[0].innerHTML=totalTally;
</code></pre>
<h2 id="the-problem">The Problem</h2>
<p>The big issue we have now occurs when a user visits this page without JS enabled. The <code>h2</code> tag will remain empty and they won&#8217;t see anything. I know this seems like a very avoidable issue, but you would be surprised how often it actually happens on the web.</p>
<h2 id="the-overly-simple-solution">The (overly simple) Solution</h2>
<p>The easiest way to avoid these types of empty tags - add static content. I know - mind blowing, right?</p>
<h3 id="html-updated">HTML (updated)</h3>
<pre><code>&#60;main&#62;
    &#60;h2 class="total-tally"&#62;200,000+&#60;&#47;h2&#62;
&#60;&#47;main&#62;
</code></pre>
<p>You might be reading this and saying to yourself, &#8220;Wow! Thanks Captain Obvious!&#8221; and that&#8217;s a fair reaction. This is an <em>obvious</em> demo on purpose. If even one single reader learns to avoid leaving empty HTML tags that are solely dependent on Javascript injection, then I&#8217;d say this demo was a huge success.</p>
<p>Rule of thumb: don&#8217;t make assumption about your users. Play it safe.</p>
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