Added in copy button

assets/master.css

@@ -5,6 +5,8 @@ h1 span { font-size: 0.6em; }
 button { font-weight: bold; width: 100px; }
 
 .minify-button { margin: 16px 0; }
+.copy-button { margin: 16px 0; }
+.copied-button { margin: 16px 0; background-color: green; }
 #outer-wrapper { overflow: hidden; }
 #wrapper { width: 65%; float: left; }
 #input { width: 99%; height: 18em; }

assets/master.js

@@ -84,6 +84,7 @@
   }
 
   byId('minify-btn').onclick = function() {
+    byId('copy-btn').disabled = false;
     byId('minify-btn').disabled = true;
     var originalValue = byId('input').value;
     minify(originalValue, getOptions(), function(minifiedValue) {
@@ -104,6 +105,23 @@
       byId('stats').innerHTML = '<span class="failure">' + escapeHTML(err) + '</span>';
       byId('minify-btn').disabled = false;
     });
+    byId('copy-btn').onclick = function() {
+      navigator.permissions.query({ name: 'clipboard-write' })
+        .then(function(permissionStatus) {
+          if (permissionStatus.state === 'granted' || permissionStatus.state === 'prompt') {
+            navigator.clipboard.writeText(byId('output').value);
+            byId('copy-btn').innerText = 'Copied!';
+            byId('copy-btn').className = 'copied-button';
+            setTimeout(function() {
+              byId('copy-btn').innerText = 'Copy Result';
+              byId('copy-btn').className = 'copy-button';
+            }, 5000);
+          }
+          else {
+            alert('Access was denied to clipboard-write, please give access to continue.');
+          }
+        });
+    };
   };
 
   byId('select-all').onclick = function() {

index.html

@@ -16,7 +16,9 @@ <h1>HTML Minifier <span>(v4.0.0)</span></h1>
           <button type="button" id="minify-btn">Minify</button>
         </div>
         <textarea rows="8" cols="40" id="output" readonly></textarea>
-
+        <div class="copy-button">
+          <button type="button" id="copy-btn" disabled>Copy Result</button>
+        </div>
         <p id="stats"></p>
       </div>
       <div id="options">