Reading from an assembly with embedded resources

Question

I built an assembly containing one js file. I marked the file as Embedded Resource and added it into AssemblyInfo file.

I can't refernce the Assembly from a web site. It is in the bin folder but I don't see the reference to it.

It seems like not having at least a class inside the assembly I can't reference it.

I would include the js file into my pages from the assembly.

How should I do this?

Thanks

Answer 1

I do exactly the same thing in one of my projects. I have a central ScriptManager class that actually caches the scripts as it pulls them, but the core of extracting the script file from the embedded resource looks like this:

internal static class ScriptManager
{
    private static Dictionary<string, string> m_scriptCache = 
                                     new Dictionary<string, string>();

    public static string GetScript(string scriptName)
    {
        return GetScript(scriptName, true);
    }

    public static string GetScript(string scriptName, bool encloseInCdata)
    {
        StringBuilder script = new StringBuilder("\r\n");

        if (encloseInCdata)
        {
            script.Append("//<![CDATA[\r\n");

        }

        if (!m_scriptCache.ContainsKey(scriptName))
        {
            var asm = Assembly.GetExecutingAssembly();

            var stream = asm.GetManifestResourceStream(scriptName);

            if (stream == null)
            {
                var names = asm.GetManifestResourceNames();
                // NOTE: you passed in an invalid name.  
                // Use the above line to determine what tyhe name should be
                // most common is not setting the script file to be an embedded resource
                if (Debugger.IsAttached) Debugger.Break();

                return string.Empty;
            }

            using (var reader = new StreamReader(stream))
            {
                var text = reader.ReadToEnd();

                m_scriptCache.Add(scriptName, text);
            }
        }

        script.Append(m_scriptCache[scriptName]);

        if (encloseInCdata)
        {
            script.Append("//]]>\r\n");
        }

        return script.ToString();
    }
}

EDIT

To provide more clarity, I've posted my ScriptManager class. To extract a script file, I simply call it like this:

var script = ScriptManager.GetScript("Fully.Qualified.Script.js");

The name you pass in it the full, case-sensitive resource name (the exception handler gets a list of them by calling GetManifestResourceNames()).

This gives you the script as a string - you can then put it out into a file, inject it into the page (which is what I'm doing) or whatever you like.

Answer 2

Assembly myAssembly = // Get your assembly somehow (see below)...
IList<string> resourceNames = myAssembly.GetManifestResourceNames();

This will return a list of all resource names that have been set as 'Embedded Resource'. The name is usually the fully qualified namespace of wherever you put that JS file. So if your project is called My.Project and you store your MyScript.js file inside a folder in your project called Resources, the full name would be My.Project.Resources.MyScript.js

If you then want to use that JS file:

Stream stream = myAssembly.GetManifestResourceStream(myResourceName);

Where myResourceName argument might be "My.Project.Resources.MyScript.js". To get that JS file in that Stream object, you'll need to write it as a file to the hard drive, and serve it from your website as a static file, something like this:

Stream stream = executingAssembly.GetManifestResourceStream(imageResourcePath);
if (stream != null)
{
    string directory = Path.GetDirectoryName("C:/WebApps/MyApp/Scripts/");

    using (Stream file = File.OpenWrite(directory + "MyScript.js"))
    {
        CopyStream(stream, file);
    }

    stream.Dispose();
}

And the code for CopyStream method:

private static void CopyStream(Stream input, Stream output)
{
    byte[] buffer = new byte[8 * 1024];
    int len;
    while ((len = input.Read(buffer, 0, buffer.Length)) > 0)
    {
        output.Write(buffer, 0, len);
    }
}

You might want to stick all this code in an Application_Start event in your Global.asax. You don't want it to run for each request

---

Now getting a reference to your Assembly is a different matter, there are many ways. One way is to include all the above code in your Assembly in question, then make sure you reference that Assembly from your main WebApp project in Visual Studio, then get a reference to the currently executing Assembly like so.

namespace My.Project
{
    public class ResourceLoader
    {
        public static void LoadResources()
        {
            Assembly myAssembly = Assembly.GetExecutingAssembly();

            // rest of code from above (snip)
        }
    }
}

Then call ResourceLoader.LoadResources() from your Application_Start event in your Global.asax.

Hope this helps

Answer 3

Fully working example (I hope):

namespace TestResources.Assembly
{
    public class ResourceLoader
    {
        public static void LoadResources()
        {
            Assembly myAssembly = Assembly.GetExecutingAssembly();

            Stream stream = myAssembly
                .GetManifestResourceStream("TestResources.Assembly.CheckAnswer.js");

            if (stream != null)
            {
                string directory = Path.GetDirectoryName("C:/WebApps/MyApp/Scripts/");

                using (Stream file = File.OpenWrite(directory + "MyScript.js"))
                {
                    CopyStream(stream, file);
                }

               stream.Dispose();
            }
        }

        private static void CopyStream(Stream input, Stream output)
        {
            byte[] buffer = new byte[8 * 1024];
            int len;

            while ((len = input.Read(buffer, 0, buffer.Length)) > 0)
            {
                output.Write(buffer, 0, len);
            }
        }
    }
}

Some caveats:

• Change "C:/WebApps/MyApp/" to wherever your web app is located, maybe write some code to work this out dynamically
• Make sure the /Scripts folder exists in your webapp root
• I think it will overwrite the 'MyScript.js' file if it already exists, but just in case you might want to add some code to check for that file and delete it

Then stick a call to this code in your Global.asax file:

protected void Application_Start()
{
    ResourceLoader.LoadResources();
}

Then the path for your web site will be /Scripts/MyScript.js eg:

<head>
    <!-- Rest of head (snip) -->
    <script type="text/javascript" src="/Scripts/MyScript.js"></script>
</head>