<p>I'm writing a simple CMS.</p>

<p>I want to be able to load a View, having it included inside a master page, and then scan the HTML so that I can replace some custom tags (like {{blog}} with my own blog output) and then serve it up to the browser.</p>

<p>How can I get access to the HTML from the ViewResult in order to intercept it?</p>

Sounds like you want to write an
```
ActionFilterAttribute
```
.  This attribute has the following methods:
OnActionExecuting
- called just before the decorated action is executed
OnActionExecuted
- called after the action method is called, but before the
```
ActionResult
```
is rendered.
OnResultExecuting
- callled before the result is rendered
OnResultExecuted
- called after the result is rendered
There is an example here which returns either JSON or XML data depending on the "Content-type" header:
Create REST API using ASP.NET MVC that speaks both Json and plain Xml