Modernizing Legacy WebForms & MVC Apps with Doconut

The Legacy Application Dilemma

Many enterprises still rely on robust, mission-critical applications built on ASP.NET WebForms or older versions of MVC. While the backend logic remains solid, the frontend experience often suffers—especially when dealing with documents.

Legacy solutions typically rely on technologies that are now obsolete or problematic:

ActiveX Controls: Only work in Internet Explorer (which is retired).
Flash/Silverlight: Completely unsupported in modern browsers.
PDF Plugins: Require users to have Acrobat Reader installed and updated.

Doconut: The Bridge to Modernity

Doconut serves as a perfect modernization tool because it supports both .NET Framework (4.5.2+) and the latest .NET Core/6/7/8. This means you can drop the exact same viewer engine into a 10-year-old WebForms app as you would into a brand-new Blazor project.

Seamless WebForms Integration

Integrating Doconut into a WebForms project is straightforward. You don't need to rewrite your entire UI.

Add the Reference: Install the NuGet package.
Add the Handler: Register the document handler in web.config.
Embed the Script: Add the JavaScript viewer to your .aspx page.

<!-- Simply standard HTML & JS, no weird objects -->
<div id="divDocViewer" style="width:100%;height:800px"></div>
<script>
    var objDoc = $("#divDocViewer").doconut({
        basePath: "/", // Path to handler
        resPath: "/js"
    });
    objDoc.View("Invoice_123.pdf");
</script>

From Plugin-Hell to HTML5

By switching to Doconut, you immediately gain:

Mobile Support: Your legacy app now works on iPads, Android tablets, and phones.
No Plugins: Users just open the page, and the document appears. Zero installation tickets for IT.
Modern Features: Add annotation, search, and zooming capabilities that old plugins never had.

Strategy: Upgrade vs. Rewrite

Complete rewrites of large legacy systems are risky and expensive. A "strangler fig" approach—upgrading specific components like the document viewer—offers high impact with low risk.

You can modernize the User Experience of viewing contracts, blueprints, and reports today, buying you time to plan a backend migration to .NET Core in the future. And when you do migrate, Doconut comes with you, code-compatible.

Don't let legacy tech hold your data hostage. Upgrade to Doconut and give your users the modern experience they expect.