Small fixes to the data extension interface

- removed mention to a missing .less file
- fixed the position of the Reset button in the preview dialog
- fixed the error for empty property selections

main/webapp/modules/core/MOD-INF/controller.js

@@ -370,7 +370,6 @@ function init() {
 
       "styles/index/default-importing-sources.less",
       "styles/views/data-table-view.less", // for the preview table's styles
-      "styles/views/extend-data-preview-dialog.less",
       "styles/index/fixed-width-parser-ui.less",
       "styles/index/xml-parser-ui.less",
       "styles/index/json-parser-ui.less"

main/webapp/modules/core/scripts/dialogs/extend-data-preview-dialog.js

@@ -107,16 +107,6 @@ ExtendReconciledDataPreviewDialog.getAllProperties = function(url, typeID, onDon
 		id: property.id,
 		name: property.name
 	    };
-	    /*if ("id2" in property) {
-	    property2.expected = property.schema2;
-	    property2.properties = [{
-		id: property.id2,
-		name: property.name2,
-		expected: property.expects
-	    }];
-	    } else {
-	    property2.expected = property.expects;
-	    } */
 	    allProperties.push(property2);
 	}
 	allProperties.sort(function(a, b) { return a.name.localeCompare(b.name); });
@@ -183,19 +173,25 @@ ExtendReconciledDataPreviewDialog.prototype._update = function() {
       columnName: this._column.name
   };
 
-  $.post(
-    "command/core/preview-extend-data?" + $.param(params), 
-    {
-      rowIndices: JSON.stringify(this._rowIndices),
-      extension: JSON.stringify(this._extension)
-    },
-    function(data) {
-      self._renderPreview(data);
-    },
-    "json"
-  ).fail(function(data) {
-	console.log(data);
-  });
+  if(this._extension.properties.length == 0) {
+    // if the column selection is empty, reset the view
+    this._elmts.previewContainer.empty();
+  } else {
+    // otherwise, refresh the preview
+    $.post(
+	"command/core/preview-extend-data?" + $.param(params),
+	{
+	rowIndices: JSON.stringify(this._rowIndices),
+	extension: JSON.stringify(this._extension)
+	},
+	function(data) {
+	self._renderPreview(data);
+	},
+	"json"
+    ).fail(function(data) {
+	    console.log(data);
+    });
+  }
 };
 
 ExtendReconciledDataPreviewDialog.prototype._addProperty = function(p) {

main/webapp/modules/core/scripts/views/data-table/extend-data-preview-dialog.html

@@ -5,7 +5,7 @@
       <tr>
         <td width="300" height="1">Add Property</td>
         <td height="1">Preview</td>
-        <td height="1" width="1%"><button class="button" bind="resetButton">Reset</button></td>
+        <td height="1" style="text-align: right"><button class="button" bind="resetButton">Reset</button></td>
       </tr>
       <tr>
         <td style="vertical-align: top;" height="1"><div class="input-container"><input bind="addPropertyInput" /></div></td>