Add history pop button

Author: SamuelTallet

static/css/mpg.css

@@ -55,6 +55,24 @@ button, input {
 
 }
 
+.CodeMirror .mpg-history-pop-button {
+
+    position: absolute;
+    right: 0;
+    top: 0;
+    z-index: 100;
+
+    border: none;
+    background: none;
+
+}
+
+.CodeMirror .mpg-history-pop-button:focus {
+
+    outline: none;
+
+}
+
 .CodeMirror-hints {
 
     font-family: Consolas, monospace;

static/js/mpg.database.query.js

@@ -27,6 +27,13 @@ MPG.databaseName = '';
  */
 MPG.collectionName = '';
 
+/**
+ * History of queries.
+ * 
+ * @type {Array}
+ */
+MPG.queryHistory = [];
+
 /**
  * List of MongoDB and SQL keywords.
  * XXX Used for autocompletion.
@@ -83,6 +90,13 @@ MPG.initializeCodeMirror = function() {
         document.querySelector('#mpg-filter-or-doc-textarea')
     );
 
+    var historyPopButton = document.createElement('button');
+    
+    historyPopButton.className = 'mpg-history-pop-button';
+    historyPopButton.innerHTML = '<i class="fa fa-history" aria-hidden="true"></i>';
+
+    document.querySelector('.CodeMirror').appendChild(historyPopButton);
+
 };
 
 /**
@@ -653,6 +667,34 @@ MPG.eventListeners.addCodeMirror = function() {
 
 };
 
+/**
+ * Adds an event listener on "History pop" button.
+ * 
+ * @returns {void}
+ */
+MPG.eventListeners.addHistoryPop = function() {
+
+    document.querySelector('.CodeMirror .mpg-history-pop-button')
+        .addEventListener('click', function(_event) {
+
+        var lastQuery = MPG.queryHistory.pop();
+
+        if ( lastQuery === MPG.codeMirror.getValue() ) {
+            lastQuery = MPG.queryHistory.pop();
+        }
+
+        if ( typeof lastQuery === 'string' ) {
+            MPG.codeMirror.setValue(lastQuery);
+            MPG.codeMirror.save();
+        } else {
+            MPG.codeMirror.setValue('');
+            MPG.codeMirror.save();
+        }
+
+    });
+
+};
+
 /**
  * Adds an event listener on "Find" button.
  * 
@@ -698,6 +740,7 @@ MPG.eventListeners.addFind = function() {
         if ( filterOrDocTextAreaValue === '' ) {
             requestBody.filter = {};
         } else {
+            MPG.queryHistory.push(filterOrDocTextAreaValue);
             requestBody.filter = JSON.parse(filterOrDocTextAreaValue);
         }
 
@@ -789,6 +832,7 @@ window.addEventListener('DOMContentLoaded', function(_event) {
     MPG.eventListeners.addCount();
     MPG.eventListeners.addDeleteOne();
     MPG.eventListeners.addCodeMirror();
+    MPG.eventListeners.addHistoryPop();
     MPG.eventListeners.addFind();
     MPG.eventListeners.addCtrlSpace();
     MPG.eventListeners.addExport();