Allow custom image to HTML conversion

2 files changed, 34 insertions, 11 deletions

diff --git a/lib/document-to-html.js b/lib/document-to-html.js
index 25892d5..47e7e86 100644
--- a/lib/document-to-html.js
+++ b/lib/document-to-html.js
@@ -80,6 +80,18 @@ function DocumentConverter(options) {
             }
         });
     }
+    
+    function defaultConvertImage(element, html, messages, callback) {
+        element.read("base64").then(function(imageBuffer) {
+            var src = "data:" + element.contentType + ";base64," + imageBuffer;
+            var attributes = {src: src};
+            if (element.altText) {
+                attributes.alt = element.altText;
+            }
+            html.selfClosing(htmlPaths.element("img", attributes));
+            callback();
+        }).fail(callback);
+    }
 
     var elementConverters = {
         "document": function(document, html, messages, callback) {
@@ -102,17 +114,7 @@ function DocumentConverter(options) {
                 }
             });
         },
-        "image": function(element, html, messages, callback) {
-            element.read("base64").then(function(imageBuffer) {
-                var src = "data:" + element.contentType + ";base64," + imageBuffer;
-                var attributes = {src: src};
-                if (element.altText) {
-                    attributes.alt = element.altText;
-                }
-                html.selfClosing(htmlPaths.element("img", attributes));
-                callback();
-            }).fail(callback);
-        }
+        "image": options.convertImage || defaultConvertImage
     };
     return {
         convertToHtml: convertToHtml
diff --git a/tests/document-to-html.tests.js b/tests/document-to-html.tests.js
index c7b7bcf..65ce341 100644
--- a/tests/document-to-html.tests.js
+++ b/tests/document-to-html.tests.js
@@ -206,6 +206,27 @@ describe('DocumentConverter', function() {
                 assert.equal(htmlImageElement.attributes.alt, "It's a hat");
             });
     });
+    
+    test('can add custom handler for images', function() {
+        var imageBuffer = new Buffer("Not an image at all!");
+        var image = new documents.Image({
+            readImage: function(encoding) {
+                return q.when(imageBuffer.toString(encoding));
+            },
+            contentType: "image/png"
+        });
+        var converter = new DocumentConverter({
+            convertImage: function(element, html, messages, callback) {
+                element.read("utf8").then(function(altText) {;
+                    html.selfClosing(htmlPaths.element("img", {alt: altText}));
+                    callback();
+                });
+            }
+        });
+        return converter.convertToHtml(image).then(function(result) {
+            assert.equal(result.value, '<img alt="Not an image at all!" />');
+        });
+    });
 });
 
 function paragraphOfText(text, styleName) {