From 1d31b59b2404570d8024722862f3678381686924 Mon Sep 17 00:00:00 2001
From: Sam Minnee <sam@silverstripe.com>
Date: Thu, 9 Jul 2009 06:38:43 +0000
Subject: [PATCH] ENHANCEMENT: Improvements to DataDifferencer for cmsworkflow.

git-svn-id: svn://svn.silverstripe.com/silverstripe/open/modules/sapphire/branches/2.3@81475 467b73ca-7a2a-4603-9d3b-597d59a354a9
---
 core/model/DataDifferencer.php | 73 ++++++++++++++++++++++++++++++----
 1 file changed, 65 insertions(+), 8 deletions(-)

diff --git a/core/model/DataDifferencer.php b/core/model/DataDifferencer.php
index 1f7bdbb77..2d87670e9 100644
--- a/core/model/DataDifferencer.php
+++ b/core/model/DataDifferencer.php
@@ -37,7 +37,12 @@ class DataDifferencer extends ViewableData {
 	
 	protected $ignoredFields = array("ID","Version","RecordID");
 	
+	/**
+	 * Construct a DataDifferencer to show the changes between $fromRecord and $toRecord.
+	 * If $fromRecord is null, this will represent a "creation".
+	 */
 	function __construct($fromRecord, $toRecord) {
+		if(!$toRecord) user_error("DataDifferencer constructed without a toRecord", E_USER_WARNING);
 		$this->fromRecord = $fromRecord;
 		$this->toRecord = $toRecord;
 	}
@@ -52,14 +57,25 @@ class DataDifferencer extends ViewableData {
 		$this->ignoredFields = array_merge($this->ignoredFields, $ignoredFields);
 	}
 	
+	/**
+	 * Get a DataObject with altered values replaced with HTML diff strings, incorporating
+	 * <ins> and <del> tags.
+	 */
 	function diffedData() {
-		$diffed = clone $this->fromRecord;
-		$fields = array_keys($diffed->getAllFields());
+		if($this->fromRecord) {
+			$diffed = clone $this->fromRecord;
+			$fields = array_keys($diffed->getAllFields());
+		} else {
+			$diffed = clone $this->toRecord;
+			$fields = array_keys($this->toRecord->getAllFields());
+		}
 		
 		foreach($fields as $field) {
 			if(in_array($field, $this->ignoredFields)) continue;
 			
-			if($this->fromRecord->$field != $this->toRecord->$field) {			
+			if(!$this->fromRecord) {
+				$diffed->$field = "<ins>" . $this->toRecord->$field . "</ins>";
+			} else if($this->fromRecord->$field != $this->toRecord->$field) {			
 				$diffed->$field = Diff::compareHTML($this->fromRecord->$field, $this->toRecord->$field);
 			}
 		}
@@ -67,21 +83,62 @@ class DataDifferencer extends ViewableData {
 		return $diffed;
 	}
 	
+	/**
+	 * Get a DataObjectSet of the changed fields.
+	 * Each element is an array data containing
+	 *  - Name: The field name
+	 *  - Title: The human-readable field title
+	 *  - Diff: An HTML diff showing the changes
+	 *  - From: The older version of the field
+	 *  - To: The newer version of the field
+	 */
 	function ChangedFields() {
 		$changedFields = new DataObjectSet();
-		$fields = array_keys($this->fromRecord->getAllFields());
+
+		if($this->fromRecord) {
+			$base = $this->fromRecord;
+			$fields = array_keys($this->fromRecord->getAllFields());
+		} else {
+			$base = $this->toRecord;
+			$fields = array_keys($this->toRecord->getAllFields());
+		}
 		
 		foreach($fields as $field) {
 			if(in_array($field, $this->ignoredFields)) continue;
 
-			if($this->fromRecord->$field != $this->toRecord->$field) {			
+			if(!$this->fromRecord || $this->fromRecord->$field != $this->toRecord->$field) {			
 				$changedFields->push(new ArrayData(array(
-					'Title' => $this->fromRecord->fieldLabel($field),
-					'Diff' => Diff::compareHTML($this->fromRecord->$field, $this->toRecord->$field),
+					'Name' => $field,
+					'Title' => $base->fieldLabel($field),
+					'Diff' => $this->fromRecord
+						? Diff::compareHTML($this->fromRecord->$field, $this->toRecord->$field)
+						: "<ins>" . $this->toRecord->$field . "</ins>",
+					'From' => $this->fromRecord ? $this->fromRecord->$field : null,
+					'To' => $this->toRecord ? $this->toRecord->$field : null,
 				)));
 			}
 		}
 		
 		return $changedFields;
 	}
-}
\ No newline at end of file
+
+	/**
+	 * Get an array of the names of every fields that has changed.
+	 * This is simpler than {@link ChangedFields()}
+	 */
+	function changedFieldNames() {
+		$diffed = clone $this->fromRecord;
+		$fields = array_keys($diffed->getAllFields());
+		
+		$changedFields = array();
+		
+		foreach($fields as $field) {
+			if(in_array($field, $this->ignoredFields)) continue;
+			if($this->fromRecord->$field != $this->toRecord->$field) {			
+				$changedFields[] = $field;
+			}
+		}
+		
+		return $changedFields;
+	}
+}