Rename private attribute _element to _el

Change-Id: I9c7a31bd6844636737ffa6456562b997f5e370a3
diff --git a/dev/js/src/vc/chooseitem.js b/dev/js/src/vc/chooseitem.js
index 039764c..5032895 100644
--- a/dev/js/src/vc/chooseitem.js
+++ b/dev/js/src/vc/chooseitem.js
@@ -82,8 +82,8 @@
       const t = this;
 
       // already defined
-      if (t._element !== undefined)
-	      return t._element;
+      if (t._el !== undefined)
+	      return t._el;
 
       // Create list item
       const li = document.createElement("li");
@@ -94,7 +94,7 @@
       li["onclick"] = t.onclick.bind(t);
 
       li.addT(t._name);
-      return t._element = li;
+      return t._el = li;
     }
   }
 });
diff --git a/dev/js/src/vc/doc.js b/dev/js/src/vc/doc.js
index fd4c318..37b0e0b 100644
--- a/dev/js/src/vc/doc.js
+++ b/dev/js/src/vc/doc.js
@@ -63,11 +63,11 @@
     update : function () {
       const t = this;
 
-      if (t._element === undefined)
+      if (t._el === undefined)
         return t.element();
       
       // Get element
-      const e = t._element;
+      const e = t._el;
 
       // Check if there is a change in the underlying data
       if (!t.__changed)
@@ -167,13 +167,13 @@
      */
     element : function () {
       const t = this;
-      if (t._element !== undefined)
-        return t._element;
+      if (t._el !== undefined)
+        return t._el;
 
-      t._element = document.createElement('div');
-      t._element.setAttribute('class', 'doc');
+      t._el = document.createElement('div');
+      t._el.setAttribute('class', 'doc');
       t.update();
-      return t._element;
+      return t._el;
     },
 
 
@@ -394,7 +394,7 @@
       const menu = KorAP._vcKeyMenu;
 
       // Insert menu
-      this._element.insertBefore(
+      this._el.insertBefore(
         menu.element(),
         this._keyE
       );
@@ -476,7 +476,7 @@
       };
 
       // Insert menu
-      this._element.insertBefore(
+      this._el.insertBefore(
         menu.element(),
         this._matchopE
       );
@@ -545,12 +545,12 @@
           };
 
           // Remove datepicker
-          that._element.removeChild(
+          that._el.removeChild(
             dp.element()
           );
         });
 
-        this._element.insertBefore(
+        this._el.insertBefore(
           dp.show(), // Get element of the date picker
           this._valueE
         );
@@ -570,14 +570,14 @@
           else
             that.type('string');
           
-          that._element.removeChild(
-            this._element
+          that._el.removeChild(
+            this._el
           );
           that.update();
         };
 
         // Insert element
-        this._element.insertBefore(
+        this._el.insertBefore(
           strElem,
           this._valueE
         );
@@ -616,10 +616,10 @@
 
       delete this["_rewrites"];
       
-      if (this._element === undefined)
+      if (this._el === undefined)
         return;
 
-      this._element.classList.remove("rewritten");
+      this._el.classList.remove("rewritten");
     },
 
 
diff --git a/dev/js/src/vc/docgroup.js b/dev/js/src/vc/docgroup.js
index 1dbd5d7..6ea5e8b 100644
--- a/dev/js/src/vc/docgroup.js
+++ b/dev/js/src/vc/docgroup.js
@@ -196,10 +196,10 @@
 	      };
       };
 
-      if (t._element === undefined)
+      if (t._el === undefined)
 	      return t;
 
-      const group = t._element;
+      const group = t._el;
       group.setAttribute('data-operation', t.operation());
 
       _removeChildren(group);
@@ -231,10 +231,10 @@
     element : function () {
       const t = this;
 
-      if (t._element !== undefined)
-	      return t._element;
+      if (t._el !== undefined)
+	      return t._el;
 
-      const e = t._element = document.createElement('div');
+      const e = t._el = document.createElement('div');
       e.setAttribute('class', 'docGroup');
 
       // Update the object - including optimization
diff --git a/dev/js/src/vc/docgroupref.js b/dev/js/src/vc/docgroupref.js
index 9f1401a..5a9196b 100644
--- a/dev/js/src/vc/docgroupref.js
+++ b/dev/js/src/vc/docgroupref.js
@@ -49,10 +49,10 @@
     update : function () {
       const t = this;
 
-      if (t._element === undefined)
+      if (t._el === undefined)
         return t.element();
 
-      const e = t._element;
+      const e = t._el;
 
       // Check if there is a change in the underlying data
       if (!t.__changed)
@@ -126,10 +126,10 @@
      */
     element : function () {
 
-      if (this._element !== undefined)
-	      return this._element;
+      if (this._el !== undefined)
+	      return this._el;
 
-      const e = this._element = document.createElement('div');
+      const e = this._el = document.createElement('div');
       e.setAttribute('class', 'doc groupref');
       this.update();
       return e;
@@ -158,14 +158,14 @@
       str.store = function (ref, regex) {
         that.ref(ref);
           
-        that._element.removeChild(
-          this._element
+        that._el.removeChild(
+          this._el
         );
         that.update();
       };
 
       // Insert element
-      this._element.insertBefore(
+      this._el.insertBefore(
         strElem,
         this._refE
       );
@@ -256,10 +256,10 @@
 
       delete this["_rewrites"];
 
-      if (this._element === undefined)
+      if (this._el === undefined)
         return;
 
-      this._element.classList.remove("rewritten");
+      this._el.classList.remove("rewritten");
     },
 
 
diff --git a/dev/js/src/vc/fragment.js b/dev/js/src/vc/fragment.js
index 0f155ff..72bd80e 100644
--- a/dev/js/src/vc/fragment.js
+++ b/dev/js/src/vc/fragment.js
@@ -89,12 +89,12 @@
      * Get the element associated with the virtual corpus
      */
     element : function () {
-      if (this._element !== undefined) {
-        return this._element;
+      if (this._el !== undefined) {
+        return this._el;
       };
 
       // Initialize element
-      const e = this._element = document.createElement('div');
+      const e = this._el = document.createElement('div');
       e.classList.add('vc', 'fragment');
 
       // Prepend info text
diff --git a/dev/js/src/vc/item.js b/dev/js/src/vc/item.js
index 59589d8..bf394b8 100644
--- a/dev/js/src/vc/item.js
+++ b/dev/js/src/vc/item.js
@@ -86,8 +86,8 @@
       const t = this;
 
       // already defined
-      if (t._element !== undefined)
-	      return t._element;
+      if (t._el !== undefined)
+	      return t._el;
 
       // Create list item
       var li = document.createElement("li");
@@ -100,7 +100,7 @@
       li["onclick"] = t.onclick.bind(t);
 
       li.addT(t._name);
-      return t._element = li;
+      return t._el = li;
     }
   };
 });
diff --git a/dev/js/src/vc/jsonld.js b/dev/js/src/vc/jsonld.js
index fdee980..06be1e0 100644
--- a/dev/js/src/vc/jsonld.js
+++ b/dev/js/src/vc/jsonld.js
@@ -49,14 +49,14 @@
       const t = this;
       if (t._ops != undefined) {
 	      t._ops._parent = undefined;
-	      if (t._ops._element !== undefined) {
-	        t._ops._element.refTo = undefined;
+	      if (t._ops._el !== undefined) {
+	        t._ops._el.refTo = undefined;
         };
 	      t._ops = undefined;
       };
 
-      if (t._element !== undefined)
-	      t._element = undefined;
+      if (t._el !== undefined)
+	      t._el = undefined;
       
       // In case of a group, destroy all operands
       if (t._operands !== undefined) {
diff --git a/dev/js/src/vc/rewritelist.js b/dev/js/src/vc/rewritelist.js
index 410c975..1d4d881 100644
--- a/dev/js/src/vc/rewritelist.js
+++ b/dev/js/src/vc/rewritelist.js
@@ -36,10 +36,10 @@
      * Get element.
      */
     element : function () {
-      if (this._element !== undefined)
-	      return this._element;
+      if (this._el !== undefined)
+	      return this._el;
 
-      const e = this._element = document.createElement('div');
+      const e = this._el = document.createElement('div');
       e.setAttribute('class', 'rewrite');
 
       const comments = [];
@@ -65,7 +65,7 @@
 
         comments.push(rewriteText + ' (' + rewrite.operation() + ')');
         
-	      this._element.appendChild(span);
+	      this._el.appendChild(span);
       }, this);
 
       e.setAttribute("title", comments.join("\n"))
diff --git a/dev/js/src/vc/statistic.js b/dev/js/src/vc/statistic.js
index 4dd5ab3..0fda3ba 100644
--- a/dev/js/src/vc/statistic.js
+++ b/dev/js/src/vc/statistic.js
@@ -38,9 +38,9 @@
      */
     element : function () {
 
-      // if this._element already exists return without doing something
-      if (this._element !== undefined) {
-        return this._element;
+      // if this._el already exists return without doing something
+      if (this._el !== undefined) {
+        return this._el;
       }
 
       // create HTML Description List Element
@@ -59,8 +59,8 @@
         statDD.addT(new Number(statistic[k]).toLocaleString());
       });
 
-      this._element = statDL;
-      return this._element;
+      this._el = statDL;
+      return this._el;
     }
   }
 
diff --git a/dev/js/src/vc/stringval.js b/dev/js/src/vc/stringval.js
index 0705033..54f92ec 100644
--- a/dev/js/src/vc/stringval.js
+++ b/dev/js/src/vc/stringval.js
@@ -93,12 +93,12 @@
 
   // Update dom element
   _update : function () {
-    if (this._element === undefined)
+    if (this._el === undefined)
       return;
  
     this._value = this._input.value;
 
-    const cl = this._element.classList;
+    const cl = this._el.classList;
 
     if (this._regexOp() && this._regex) {
       cl.add('regex');
@@ -121,7 +121,7 @@
    * Put focus on element
    */
   focus : function () {
-    this._element.children[0].focus();
+    this._el.children[0].focus();
   },
 
 
@@ -129,11 +129,11 @@
    * Get the associated dom element.
    */
   element : function () {
-    if (this._element !== undefined)
-      return this._element;
+    if (this._el !== undefined)
+      return this._el;
 
     // Create element
-    const e = this._element = document.createElement('div');
+    const e = this._el = document.createElement('div');
     e.setAttribute('tabindex', 0);
     e.style.outline = 0;
 
diff --git a/dev/js/src/vc/unspecified.js b/dev/js/src/vc/unspecified.js
index fe089a3..5bda78c 100644
--- a/dev/js/src/vc/unspecified.js
+++ b/dev/js/src/vc/unspecified.js
@@ -78,11 +78,11 @@
     update : function () {
       const t = this;
 
-      if (t._element === undefined)
+      if (t._el === undefined)
 	      return t.element();
 
       // Remove element content
-      _removeChildren(t._element);
+      _removeChildren(t._el);
 
       const ellipsis = document.createElement('span');
       ellipsis.addT(loc.EMPTY);
@@ -90,16 +90,16 @@
       // Click on empty criterion
       ellipsis.addEventListener('click', t.onclick.bind(t));
 
-      t._element.appendChild(ellipsis);
+      t._el.appendChild(ellipsis);
 
       // Set ref - TODO: Cleanup!
-      t._element.refTo = t;
+      t._el.refTo = t;
 
       // Set operators
       if (t._parent !== undefined &&
           t.parent().ldType() !== null) {
 
-	      t._element.appendChild(
+	      t._el.appendChild(
 	        t.operators(
 	          false,
 	          false,
@@ -117,12 +117,12 @@
      */
     element : function () {
       const t = this;
-      if (t._element !== undefined)
-	      return t._element;
-      t._element = document.createElement('div');
-      t._element.setAttribute('class', 'doc unspecified');
+      if (t._el !== undefined)
+	      return t._el;
+      t._el = document.createElement('div');
+      t._el.setAttribute('class', 'doc unspecified');
       t.update();
-      return t._element;
+      return t._el;
     },
 
 
@@ -140,9 +140,9 @@
       const menu = KorAP._vcKeyMenu;
 
       // Add key menu element at the correct position
-      this._element.insertBefore(
+      this._el.insertBefore(
 	      menu.element(),	
-	      this._element.firstChild
+	      this._el.firstChild
       );
 
       const that = this;