Merge pull request squizlabs#20 from lwright-sq/master

Add function to detect layout tables, and adjust SC 1.3.1 tests for them

Author: Luke Wright

HTMLCS.js

@@ -635,6 +635,11 @@ var HTMLCS = new function()
         };
 
         this.isLayoutTable = function(table) {
+            var th = table.querySelector('th');
+            if (th === null) {
+                return true;
+            }
+
             return false;
         };
 

Standards/WCAG2AAA/Sniffs/Principle1/Guideline1_3/1_3_1.js

@@ -75,6 +75,7 @@ var HTMLCS_WCAG2AAA_Sniffs_Principle1_Guideline1_3_1_3_1 = {
                 break;
 
                 case 'table':
+                    this.testGeneralTable(element);
                     this.testTableHeaders(element);
                     this.testTableCaptionSummary(element);
                 break;
@@ -676,20 +677,32 @@ var HTMLCS_WCAG2AAA_Sniffs_Principle1_Guideline1_3_1_3_1 = {
         summary = summary.replace(/^\s*(.*?)\s*$/g, '$1');
 
         if (summary !== '') {
-            if (caption === summary) {
-                HTMLCS.addMessage(HTMLCS.ERROR, table, 'If this table is a data table, and both a summary attribute and a caption element are present, the summary should not duplicate the caption.', 'H39,H73.4');
-            }
+            if (HTMLCS.util.isLayoutTable(table) === true) {
+                HTMLCS.addMessage(HTMLCS.ERROR, table, 'This table appears to be used for layout, but contains a summary attribute. Layout tables must not contain summary attributes, or if supplied, must be empty.', 'H73.3.LayoutTable');
+            } else {
+                if (caption === summary) {
+                    HTMLCS.addMessage(HTMLCS.ERROR, table, 'If this table is a data table, and both a summary attribute and a caption element are present, the summary should not duplicate the caption.', 'H39,H73.4');
+                }
 
-            HTMLCS.addMessage(HTMLCS.NOTICE, table, 'If this table is a data table, check that the summary attribute describes the table\'s organization or explains how to use the table.', 'H73.3.Check');
+                HTMLCS.addMessage(HTMLCS.NOTICE, table, 'If this table is a data table, check that the summary attribute describes the table\'s organization or explains how to use the table.', 'H73.3.Check');
+            }
         } else {
-            HTMLCS.addMessage(HTMLCS.WARNING, table, 'If this table is a data table, consider using the summary attribute of the table element to give an overview of this table.', 'H73.3.NoSummary');
+            if (HTMLCS.util.isLayoutTable(table) === false) {
+                HTMLCS.addMessage(HTMLCS.WARNING, table, 'If this table is a data table, consider using the summary attribute of the table element to give an overview of this table.', 'H73.3.NoSummary');
+            }
         }//end if
 
         if (caption !== '') {
-            HTMLCS.addMessage(HTMLCS.NOTICE, table, 'If this table is a data table, check that the caption element accurately describes this table.', 'H39.3.Check');
+            if (HTMLCS.util.isLayoutTable(table) === true) {
+                HTMLCS.addMessage(HTMLCS.ERROR, table, 'This table appears to be used for layout, but contains a caption element. Layout tables must not contain captions.', 'H39.3.LayoutTable');
+            } else {
+                HTMLCS.addMessage(HTMLCS.NOTICE, table, 'If this table is a data table, check that the caption element accurately describes this table.', 'H39.3.Check');
+            }
         } else {
-            HTMLCS.addMessage(HTMLCS.WARNING, table, 'If this table is a data table, consider using a caption element to the table element to identify this table.', 'H39.3.NoCaption');
-        }
+            if (HTMLCS.util.isLayoutTable(table) === false) {
+                HTMLCS.addMessage(HTMLCS.WARNING, table, 'If this table is a data table, consider using a caption element to the table element to identify this table.', 'H39.3.NoCaption');
+            }
+        }//end if
     },
 
     /**
@@ -900,5 +913,21 @@ var HTMLCS_WCAG2AAA_Sniffs_Principle1_Guideline1_3_1_3_1 = {
                 HTMLCS.addMessage(HTMLCS.WARNING, element, 'If this element contains a navigation section, it is recommended that it be marked up as a list.', 'H48');
             }
         }//end if
+    },
+
+    /**
+     * Provide generic messages for tables depending on what type of table they
+     * are - layout or data.
+     *
+     * @param {DOMNode} table The table element to test.
+     *
+     * @returns void
+     */
+    testGeneralTable: function(table) {
+        if (HTMLCS.util.isLayoutTable(table) === true) {
+            HTMLCS.addMessage(HTMLCS.NOTICE, table, 'This table appears to be a layout table. If it is meant to instead be a data table, ensure header cells are identified using th elements.', 'LayoutTable');
+        } else {
+            HTMLCS.addMessage(HTMLCS.NOTICE, table, 'This table appears to be a data table. If it is meant to instead be a layout table, ensure there are no th elements, and no summary or caption.', 'DataTable');
+        }
     }
 };