Javascript insert to HTML

There's several ways to do this, but I prefer a STREAM profile for its simplicity, flexibility, and speed. To make it work, apply a generic STREAM profile to your virtual server and this iRule:

 

 

 

when HTTP_REQUEST {
     Disable the stream filter for all requests
    STREAM::disable
    
     LTM does not decompress response content, so if the server has compression enabled
     and it cannot be disabled on the server, we can prevent the server from sending
     a compressed response by removing the compression offerings from the client
    HTTP::header remove "Accept-Encoding"
}
when HTTP_RESPONSE {
     Check if response type is text
    if { [HTTP::header value Content-Type] contains "text" } {

         Define the stream replacement
        STREAM::expression {@@@}

         Enable the stream filter for this response only
        STREAM::enable
    }
}

 

 

In this example I'm replacing the end body tag with a piece of JavaScript code and another end body tag. Placing the JavaScript at the bottom of the page has roughly the same effect as an onload statement in the beginning body tag, plus it's easier to manipulate. You could, alternatively, replace the end head tag with a JavaScript function and another end head tag, then replace the beginning body tag with one that has an onload statement.