Add debounced update plugin

plugins/debounce-update.js

@@ -0,0 +1,40 @@
+/**
+ * Debounce the update and highlighting function
+ *  https://medium.com/@jamischarles/what-is-debouncing-2505c0648ff1
+ */
+codeInput.plugins.DebounceUpdate = class extends codeInput.Plugin {
+    /**
+     * Create a debounced update plugin to pass into a template
+     * @param {Number} delayMs Delay, in ms, to wait until updating the syntax highlighting 
+     */
+    constructor(delayMs) {
+        super();
+        this.delayMs = delayMs;
+    }
+    /* Runs before elements are added into a `code-input`; Params: codeInput element) */
+    beforeElementsAdded(codeInput) {
+        console.log(codeInput, "before elements added");
+        this.update = codeInput.update.bind(codeInput); // Save previous update func
+        codeInput.update = this.updateDebounced.bind(this, codeInput);
+    }
+
+    /**
+     * Debounce the `update` function
+     */
+    updateDebounced(codeInput, text) {
+        // Editing - cancel prev. timeout
+        if(this.debounceTimeout != null) {
+            window.clearTimeout(this.debounceTimeout);
+        }
+
+        this.debounceTimeout = window.setTimeout(() => {
+            // Closure arrow function can take in variables like `text`
+            this.update(text);
+        }, this.delayMs);
+    }
+
+    // this.`update` function is original function
+
+    debounceTimeout = null; // Timeout until update
+    delayMs = 0; // Time until update
+}