Introduction

When developing web applications in C#, it’s common to embed resources, like JavaScript files, into your assembly. However, when your JavaScript needs to reference additional static assets, such as images, it can become tricky to manage these references properly. You might find yourself wondering how to tokenize references to these resources so they can be seamlessly used within your JavaScript code.

In this blog post, we’ll tackle this issue by showing you how to dynamically manage the references of embedded resources in a structured way.

The Challenge

You have JavaScript files that are embedded in your assembly, and typically you add them to your pages using ClientScriptManager.GetWebResourceUrl(). However, referencing other static assets, like images, needs a more refined approach.

For example, instead of directly using an image URL:

this.drophint = document.createElement('img');
this.drophint.src = '/_layouts/images/dragdrophint.gif';

You want to convert it into a more scalable format like:

this.drophint = document.createElement('img');
this.drophint.src = '{resource:assembly.location.dragdrophint.gif}';

So, how do you achieve this? The answer lies in using a dynamic JavaScript associative array to store resource URLs server-side and reference them client-side.

The Solution

Step 1: Create a Dynamic JavaScript Array

To dynamically manage your resource URLs, you can create an associative array that holds the paths of your embedded resources. Here’s how you can do this in your server-side code:

Server-side Code Example

StringBuilder script = new StringBuilder();
script.Append("var imgResources = {};");
script.AppendFormat("imgResources['{0}'] = '{1}';", 
    "drophint", 
    Page.ClientScript.GetWebResourceUrl(Page.GetType(), "assembly.location.dragdrophint.gif"));
script.AppendFormat("imgResources['{0}'] = '{1}';", 
    "anotherimg", 
    Page.ClientScript.GetWebResourceUrl(Page.GetType(), "assembly.location.anotherimg.gif"));

Page.ClientScript.RegisterClientScriptBlock(
    Page.GetType(),
    "imgResources",
    script.ToString(), 
    true);

Explanation

1. StringBuilder: A StringBuilder object is used to efficiently build the JavaScript code.
2. Associative Array: We create a variable named imgResources that will contain the URLs of our images.
3. GetWebResourceUrl(): This method retrieves the URL for the embedded resources you specified, allowing you to store these URLs in the array.

Step 2: Reference the Resources in Client-Side Code

With the JavaScript dynamic array in place, you can easily reference your images in the client-side code like this:

Client-side Code Example

this.drophint = document.createElement('img');
this.drophint.src = imgResources['drophint'];
this.anotherimg = document.createElement('img');
this.anotherimg.src = imgResources['anotherimg'];

Benefits

• Scalability: Easily add more resources without cluttering your JavaScript files.
• Manageability: Maintain a single point of reference for URLs, making updates seamless.
• Dynamic Loading: Ensure your assets load based on the resources embedded in the assembly.

Conclusion

By structuring your approach to referencing embedded resources in your C# web applications using a dynamic JavaScript associative array, you can streamline the process of managing static asset URLs. This method not only improves maintainability but also enhances the scalability of your application.

Implementing this solution not only saves you time but also future-proofs your codebase for easy updates and modifications.

Happy coding!