Remove callback option

Author: nikitaeverywhere

package.json

@@ -5,7 +5,7 @@
   "printableName": "Cache Web Terminal",
   "description": "Web-based terminal emulator for Caché administering.",
   "author": "ZitRo",
-  "version": "4.5.0",
+  "version": "4.6.0",
   "gaID": "UA-83005064-2",
   "releaseNumber": 26,
   "scripts": {

readme.md

@@ -143,6 +143,14 @@ The next table demonstrates available API. Left column are `terminal` object pro
             with one of the terminal mode constants, such as <code>MODE_PROMPT</code>.
         </td>
     </tr>
+    <tr>
+        <td>removeCallback(<b>callback</b>)</td>
+        <td>
+            Remove any previously assigned <b>callback</b>. Any function which accepts callback
+            returns it, and you can pass the callback here once you no longer need it to stop it
+            from firing.
+        </td>
+    </tr>
     <tr>
         <td>print(<b>text</b>)</td>
         <td>

src/client/js/index.js

@@ -162,10 +162,36 @@ Terminal.prototype.execute = function (command, options, callback) {
         bufferOutput: +(typeof callback === "function")
     });
     if (typeof callback === "function") {
-        executeCallback = callback;
+        return executeCallback = callback;
     }
 };
 
+/**
+ * Remove previously assigned callback.
+ * @param {function} callback
+ * @returns {boolean} - If callback was removed.
+ */
+Terminal.prototype.removeCallback = function (callback) {
+    let i,
+        deleted = false;
+    if ((i = userInputHandlers.indexOf(callback)) !== -1) {
+        userInputHandlers.splice(i, 1);
+        return true;
+    }
+    if (typeof executeCallback === "function") {
+        executeCallback = null;
+        return true;
+    }
+    for (i = 0; i < outputHandlers.length; ++i) {
+        if (outputHandlers[i].callback !== callback)
+            continue;
+        outputHandlers.splice(i, 1);
+        --i;
+        deleted = true;
+    }
+    return deleted;
+};
+
 export function promptCallback (data) {
     if (typeof executeCallback === "function") {
         executeCallback([ data ]);