From 36d0dc73f4439b0b65c38c2bbf349dad1d13297b Mon Sep 17 00:00:00 2001
From: Erik Hansen <erikpallhansen@gmail.com>
Date: Sat, 9 May 2015 14:38:23 -0500
Subject: [PATCH] [FEATURE] Allow disabling of "inline style" and "style block"
 parsing

* Added two new methods: disableInlineStylesParsing and
  disableStyleBlocksParsing
* Added unit tests to cover the two new options
* Updated documentation to cover new options
* Fixes #155
---
 Classes/Emogrifier.php        | 124 ++++++++++++++++++++++++++--------
 README.md                     |  16 +++++
 Tests/Unit/EmogrifierTest.php |  73 ++++++++++++++++++++
 3 files changed, 186 insertions(+), 27 deletions(-)

diff --git a/Classes/Emogrifier.php b/Classes/Emogrifier.php
index 88afc3d2..479dfbde 100644
--- a/Classes/Emogrifier.php
+++ b/Classes/Emogrifier.php
@@ -101,6 +101,26 @@ class Emogrifier
      */
     private $styleAttributesForNodes = array();
 
+    /**
+     * Determines whether the "style" attributes of tags in the the HTML passed to this class should be preserved.
+     * If set to false, the value of the style attributes will be discarded.
+     *
+     * @var bool
+     */
+    private $isInlineStyleAttributesParsingEnabled = true;
+
+    /**
+     * Determines whether the <style> blocks in the HTML passed to this class should be parsed.
+     *
+     * If set to true, the <style> blocks will be removed from the HTML and their contents will be applied to the HTML
+     * via inline styles.
+     *
+     * If set to false, the <style> blocks will be left as they are in the HTML.
+     *
+     * @var bool
+     */
+    private $isStyleBlocksParsingEnabled = true;
+
     /**
      * This attribute applies to the case where you want to preserve your original text encoding.
      *
@@ -190,25 +210,11 @@ public function emogrify()
         if ($nodesWithStyleAttributes !== false) {
             /** @var \DOMElement $node */
             foreach ($nodesWithStyleAttributes as $node) {
-                $normalizedOriginalStyle = preg_replace_callback(
-                    '/[A-z\\-]+(?=\\:)/S',
-                    function (array $m) {
-                        return strtolower($m[0]);
-                    },
-                    $node->getAttribute('style')
-                );
-
-                // in order to not overwrite existing style attributes in the HTML, we have to save
-                // the original HTML styles
-                $nodePath = $node->getNodePath();
-                if (!isset($this->styleAttributesForNodes[$nodePath])) {
-                    $this->styleAttributesForNodes[$nodePath] = $this->parseCssDeclarationBlock(
-                        $normalizedOriginalStyle
-                    );
-                    $this->visitedNodes[$nodePath] = $node;
+                if ($this->isInlineStyleAttributesParsingEnabled) {
+                    $this->normalizeStyleAttributes($node);
+                } else {
+                    $node->removeAttribute('style');
                 }
-
-                $node->setAttribute('style', $normalizedOriginalStyle);
             }
         }
 
@@ -216,7 +222,9 @@ function (array $m) {
         // (these blocks should be appended so as to have precedence over conflicting styles in the existing CSS)
         $allCss = $this->css;
 
-        $allCss .= $this->getCssFromAllStyleNodes($xpath);
+        if ($this->isStyleBlocksParsingEnabled) {
+            $allCss .= $this->getCssFromAllStyleNodes($xpath);
+        }
 
         $cssParts = $this->splitCssAndMediaQuery($allCss);
 
@@ -277,14 +285,8 @@ function (array $m) {
             }
         }
 
-        // now iterate through the nodes that contained inline styles in the original HTML
-        foreach ($this->styleAttributesForNodes as $nodePath => $styleAttributesForNode) {
-            $node = $this->visitedNodes[$nodePath];
-            $currentStyleAttributes = $this->parseCssDeclarationBlock($node->getAttribute('style'));
-            $node->setAttribute(
-                'style',
-                $this->generateStyleStringFromDeclarationsArrays($currentStyleAttributes, $styleAttributesForNode)
-            );
+        if ($this->isInlineStyleAttributesParsingEnabled) {
+            $this->fillStyleAttributesWithMergedStyles();
         }
 
         // This removes styles from your email that contain display:none.
@@ -315,6 +317,26 @@ function (array $m) {
         }
     }
 
+    /**
+     * Disables the parsing of inline styles.
+     *
+     * @return void
+     */
+    public function disableInlineStyleAttributesParsing()
+    {
+        $this->isInlineStyleAttributesParsingEnabled = false;
+    }
+
+    /**
+     * Disables the parsing of <style> blocks.
+     *
+     * @return void
+     */
+    public function disableStyleBlocksParsing()
+    {
+        $this->isStyleBlocksParsingEnabled = false;
+    }
+
     /**
      * Clears all caches.
      *
@@ -396,6 +418,54 @@ public function removeUnprocessableHtmlTag($tagName)
         }
     }
 
+    /**
+     * Normalizes the value of the "style" attribute and saves it.
+     *
+     * @param \DOMElement $node
+     *
+     * @return void
+     */
+    private function normalizeStyleAttributes(\DOMElement $node)
+    {
+        $normalizedOriginalStyle = preg_replace_callback(
+            '/[A-z\\-]+(?=\\:)/S',
+            function (array $m) {
+                return strtolower($m[0]);
+            },
+            $node->getAttribute('style')
+        );
+
+        // in order to not overwrite existing style attributes in the HTML, we
+        // have to save the original HTML styles
+        $nodePath = $node->getNodePath();
+        if (!isset($this->styleAttributesForNodes[$nodePath])) {
+            $this->styleAttributesForNodes[$nodePath] = $this->parseCssDeclarationBlock($normalizedOriginalStyle);
+            $this->visitedNodes[$nodePath] = $node;
+        }
+
+        $node->setAttribute('style', $normalizedOriginalStyle);
+    }
+
+    /**
+     * Merges styles from styles attributes and style nodes and applies them to the attribute nodes
+     *
+     * return @void
+     */
+    private function fillStyleAttributesWithMergedStyles()
+    {
+        foreach ($this->styleAttributesForNodes as $nodePath => $styleAttributesForNode) {
+            $node = $this->visitedNodes[$nodePath];
+            $currentStyleAttributes = $this->parseCssDeclarationBlock($node->getAttribute('style'));
+            $node->setAttribute(
+                'style',
+                $this->generateStyleStringFromDeclarationsArrays(
+                    $currentStyleAttributes,
+                    $styleAttributesForNode
+                )
+            );
+        }
+    }
+
     /**
      * This method merges old or existing name/value array with new name/value array
      * and then generates a string of the combined style suitable for placing inline.
diff --git a/README.md b/README.md
index dbe56616..8778deff 100644
--- a/README.md
+++ b/README.md
@@ -63,6 +63,22 @@ After you have set the HTML and CSS, you can call the `emogrify` method to merge
 
     $mergedHtml = $emogrifier->emogrify();
 
+## Options
+
+There are several options that you can set on the Emogrifier object before 
+calling the `emogrify` method:
+
+* `$emogrifier->disableStyleBlocksParsing()` - By default, Emogrifier will grab
+  all `<style>` blocks in the HTML and will apply the CSS styles as inline
+  "style" attributes to the HTML. The `<style>` blocks will then be removed 
+  from the HTML. If you want to disable this functionality so that Emogrifier
+  leaves these `<style>` blocks in the HTML and does not parse them, you should
+  use this option.
+* `$emogrifier->disableInlineStylesParsing()` - By default, Emogrifier
+  preserves all of the "style" attributes on tags in the HTML you pass to it.
+  However if you want to discard all existing inline styles in the HTML before
+  the CSS is applied, you should use this option.
+
 
 ## Installing with Composer
 
diff --git a/Tests/Unit/EmogrifierTest.php b/Tests/Unit/EmogrifierTest.php
index ccca2913..9016a2f4 100644
--- a/Tests/Unit/EmogrifierTest.php
+++ b/Tests/Unit/EmogrifierTest.php
@@ -945,6 +945,79 @@ public function emogrifyAppliesCssFromStyleNodes()
         );
     }
 
+    /**
+     * @test
+     */
+    public function emogrifyWhenDisabledNotAppliesCssFromStyleBlocks()
+    {
+        $styleAttributeValue = 'color: #ccc;';
+        $html = $this->html5DocumentType . self::LF .
+            '<html><style type="text/css">html {' . $styleAttributeValue . '}</style></html>';
+        $this->subject->setHtml($html);
+        $this->subject->disableStyleBlocksParsing();
+
+        $this->assertNotContains(
+            '<html style="' . $styleAttributeValue . '">',
+            $this->subject->emogrify()
+        );
+    }
+
+    /**
+     * @test
+     */
+    public function emogrifyWhenStyleBlocksParsingDisabledKeepInlineStyles()
+    {
+        $styleAttributeValue = 'text-align: center;';
+        $html = $this->html5DocumentType . self::LF .
+            '<html><head><style type="text/css">p { color: #ccc; }</style></head>'
+                . '<body><p style="' . $styleAttributeValue . '">paragraph</p></body></html>';
+        $expected = '<p style="' . $styleAttributeValue . '">';
+        $this->subject->setHtml($html);
+        $this->subject->disableStyleBlocksParsing();
+
+        $this->assertContains(
+            $expected,
+            $this->subject->emogrify()
+        );
+    }
+
+    /**
+     * @test
+     */
+    public function emogrifyWhenDisabledNotAppliesCssFromInlineStyles()
+    {
+        $styleAttributeValue = 'color: #ccc;';
+        $html = $this->html5DocumentType . self::LF .
+            '<html style="' . $styleAttributeValue . '"></html>';
+        $expected = '<html></html>';
+        $this->subject->setHtml($html);
+        $this->subject->disableInlineStyleAttributesParsing();
+
+        $this->assertContains(
+            $expected,
+            $this->subject->emogrify()
+        );
+    }
+
+    /**
+     * @test
+     */
+    public function emogrifyWhenInlineStyleAttributesParsingDisabledKeepStyleBlockStyles()
+    {
+        $styleAttributeValue = 'color: #ccc;';
+        $html = $this->html5DocumentType . self::LF .
+            '<html><head><style type="text/css">p { ' . $styleAttributeValue . ' }</style></head>'
+                . '<body><p style="text-align: center;">paragraph</p></body></html>';
+        $expected = '<p style="' . $styleAttributeValue . '">';
+        $this->subject->setHtml($html);
+        $this->subject->disableInlineStyleAttributesParsing();
+
+        $this->assertContains(
+            $expected,
+            $this->subject->emogrify()
+        );
+    }
+
     /**
      * @test
      */