API Introduce $FromEnd variable for iterators

docs/en/02_Developer_Guides/01_Templates/01_Syntax.md

@@ -296,8 +296,11 @@ iteration.
  * `$Even`, `$Odd`: Returns boolean, handy for zebra striping
  * `$EvenOdd`: Returns a string, either 'even' or 'odd'. Useful for CSS classes.
  * `$First`, `$Last`, `$Middle`: Booleans about the position in the list
- * `$FirstLast`: Returns a string, "first", "last", or "". Useful for CSS classes.
+ * `$FirstLast`: Returns a string, "first", "last", "first last" (if both), or "". Useful for CSS classes.
- * `$Pos`: The current position in the list (integer). Will start at 1.
+ * `$Pos`: The current position in the list (integer).
+   Will start at 1, but can take a starting index as a parameter.
+ * `$FromEnd`: The position of the item from the end (integer).
+   Last item defaults to 1, but can be passed as a parameter.
  * `$TotalItems`: Number of items in the list (integer)
 
 	:::ss

docs/en/04_Changelogs/3.2.0.md

@@ -460,3 +460,4 @@ coding conventions. E.g. `DB::requireTable` is now `DB::require_table`
    This is in order to promote better referencing of elements across the codebase.
    See `FulltextSearchable->enable` for example.
  * `FormField` subclasses must now use `validate(Validator $validator)` as the interface has changed for this function
+ * `$FromEnd` iterator variable now available in templates.

tests/view/SSViewerTest.php

@@ -830,7 +830,19 @@ after')
 
 		//test Pos
 		$result = $this->render('<% loop Set %>$Pos<% end_loop %>',$data);
-		$this->assertEquals("12345678910",$result,"Even and Odd is returned in sequence numbers rendered in order");
+		$this->assertEquals("12345678910", $result, '$Pos is rendered in order');
+
+		//test Pos
+		$result = $this->render('<% loop Set %>$Pos(0)<% end_loop %>',$data);
+		$this->assertEquals("0123456789", $result, '$Pos(0) is rendered in order');
+
+		//test FromEnd
+		$result = $this->render('<% loop Set %>$FromEnd<% end_loop %>',$data);
+		$this->assertEquals("10987654321", $result, '$FromEnd is rendered in order');
+
+		//test FromEnd
+		$result = $this->render('<% loop Set %>$FromEnd(0)<% end_loop %>',$data);
+		$this->assertEquals("9876543210", $result, '$FromEnd(0) rendered in order');
 
 		//test Total
 		$result = $this->render('<% loop Set %>$TotalItems<% end_loop %>',$data);

view/SSViewer.php

@@ -206,6 +206,7 @@ class SSViewer_BasicIteratorSupport implements TemplateIteratorProvider {
 			'Odd',
 			'EvenOdd',
 			'Pos',
+			'FromEnd',
 			'TotalItems',
 			'Modulus',
 			'MultipleOf',
@@ -312,6 +313,17 @@ class SSViewer_BasicIteratorSupport implements TemplateIteratorProvider {
 		return $this->iteratorPos + $startIndex;
 	}
 
+	/**
+	 * Return the position of this item from the last item in the list. The position of the final
+	 * item is $endIndex, which defaults to 1.
+	 *
+	 * @param integer $endIndex Value of the last item
+	 * @return int
+	 */
+	public function FromEnd($endIndex = 1) {
+		return $this->iteratorTotalItems - $this->iteratorPos + $endIndex - 1;
+	}
+
 	/**
 	 * Return the total number of "sibling" items in the dataset.
 	 *