I know this is old, but I ran into it today. It looks UIWebView will NOT open macro-enabled Office files directly. For example, the following code fails -
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:filePath]]];
The code above fails ONLY for macro-enabled Office files - it works just fine for .docx, .pptx, .rtf, .pdf, .txt, etc. files. However, if we pull the file into NSData and then provide the mime type explicitly to UIWebView, the file will open. The code below will open these macro-enabled Office files -
// this will open a .pptm file - replace mime type as necessary for other macro-enabled file types
NSData* fileData = [NSData dataWithContentsOfFile:filePath];
[webView loadData:fileData MIMEType:@"application/vnd.ms-powerpoint.presentation.macroEnabled.12" textEncodingName:nil baseURL:nil];
Tested with .pptm, .ppsm, .potm, .docm, .xlsm