Warn on unsupported image types

2 files changed, 49 insertions, 15 deletions

diff --git a/lib/docx/document-xml-reader.js b/lib/docx/document-xml-reader.js
index 12016b0..e290792 100644
--- a/lib/docx/document-xml-reader.js
+++ b/lib/docx/document-xml-reader.js
@@ -215,23 +215,34 @@ function DocumentXmlReader(options) {
             .getElementsByTagName("pic:blipFill")
             .getElementsByTagName("a:blip");
         
-        var results = blips.map(function(blip) {
-            var relationshipId = blip.attributes["r:embed"];
-            var imagePath = joinZipPath("word", relationships[relationshipId].target);
-            var readImage = docxFile.read.bind(docxFile, imagePath);
-            var altText = element.first("wp:docPr").attributes.descr;
-            
-            var image = documents.Image({
-                readImage: readImage,
-                altText: altText,
-                contentType: contentTypes.findContentType(imagePath)
-            });
-            return new Result(image);
-        });
+        return Result.combine(blips.map(readBlip.bind(null, element)));
+    }
+    
+    function readBlip(element, blip) {
+        var relationshipId = blip.attributes["r:embed"];
+        var imagePath = joinZipPath("word", relationships[relationshipId].target);
+        var readImage = docxFile.read.bind(docxFile, imagePath);
+        var altText = element.first("wp:docPr").attributes.descr;
+        var contentType = contentTypes.findContentType(imagePath);
         
-        return Result.combine(results);
+        var image = documents.Image({
+            readImage: readImage,
+            altText: altText,
+            contentType: contentType
+        });
+        var warnings = supportedImageTypes[contentType] ?
+            [] : warning("Image of type " + contentType + " is unlikely to display in web browsers");
+        return new Result(image, warnings);
     }
 }
+    
+var supportedImageTypes = {
+    "image/png": true,
+    "image/gif": true,
+    "image/jpeg": true,
+    "image/svg+xml": true,
+    "image/tiff": true
+};
 
 var ignoreElements = {
     "w:bookmarkStart": true,
diff --git a/tests/docx/document-xml-reader.tests.js b/tests/docx/document-xml-reader.tests.js
index 53f2aa0..0b5a75f 100644
--- a/tests/docx/document-xml-reader.tests.js
+++ b/tests/docx/document-xml-reader.tests.js
@@ -34,7 +34,8 @@ function convertXmlToDocumentValue(element, options) {
 var fakeContentTypes = {
     findContentType: function(filePath) {
         var extensionTypes = {
-            ".png": "image/png"
+            ".png": "image/png",
+            ".emf": "image/x-emf"
         };
         return extensionTypes[path.extname(filePath)];
     }
@@ -289,6 +290,28 @@ describe("readXmlElement: ", function() {
             });
     });
     
+    test("warning if unsupported image type", function() {
+        var drawing = createInlineImage({
+            relationshipId: "rId5",
+            description: "It's a hat"
+        });
+        
+        var imageBuffer = new Buffer("Not an image at all!");
+        var reader = new DocumentXmlReader({
+            relationships: {
+                "rId5": {target: "media/hat.emf"}
+            },
+            contentTypes: fakeContentTypes,
+            docxFile: createFakeDocxFile({
+                "word/media/hat.emf": imageBuffer
+            })
+        });
+        var result = reader.readXmlElement(drawing);
+        assert.deepEqual(result.messages, [warning("Image of type image/x-emf is unlikely to display in web browsers")]);
+        var element = single(result.value);
+        assert.equal(element.contentType, "image/x-emf");
+    });
+    
     test("no elements created if image cannot be found in w:drawing", function() {
         var drawing = new XmlElement("w:drawing", {}, []);