ASP.NET MVC Dynamically generated image URLs

asp.net-mvc, model-view-controller

Solution

Try the following approach.

A model class for an image tag.

public class ImageModel
{
    public String Source { get; set; }
    public String Title { get; set; }
}

Helper

public static String Image(this HtmlHelper helper, String source, String title)
{
    var builder = new TagBuilder("img");
    builder.MergeAttribute("src", source);
    builder.MergeAttribute("title", title);
    return builder.ToString();
}

View with `Model.Images` of type `IEnumerable<ImageModel>`

...    
<%= Html.Image(Model.Images[0].Source, Model.Images[0].Title) %>

Action

public ActionResult ActionName(/*whatever*/)
{
    // ...
    var model = ...;
    //...

    var model0 = ImageModel();
    if (Image0.ImageLocation == ImageLocation.AmazonS3)
        model0.Source = "an amazon url";
    else
        model0.Source = Url.Action("GetImageFromDatabaseOrFileSystem", "MyController", new { Id = Image0.Id });
    model0.Title = "some title";
    model.Images.Add(model0);
    // ...
    return View(model);
}

An action is a kind of a pseudo code, however the idea should be clear.

Problem

I have an ASP.NET MVC application where I am displaying images. These images could be located on the file system or inside a database. This is fine as I can use Url.Action in my image, call the action on my controller and return the image from the relevant location. However, I want to be able to support images stored in Amazon S3. In this case, I don't want my controller action to return the image, it should instead generate an image URL for Amazon S3. Although I could just perform this logic inside my view e.g. <%if (Model.Images[0].ImageLocation == ImageLocation.AmazonS3) {%> // render amazon image I need to ensure that the image exists first. Essentially I need to pass a size value to my controller so that I can check that the image exists in that size (whether it be in the database, file system or amazon s3). Once I am sure that the image exists, then I return the URL to it. Hope that makes sense, Ben

Original source