Monthly Archives: November 2010

Hacking the Delicious extension for Chrome

I’ve recently moved from Firefox to Chrome. I use Delicious for managing my public and private bookmarks, and have installed the plugins for both browsers.

In moving to Chrome and installing the Delicious Tools extension, one thing I really missed from the Firefox-based add-on was the ability to set a simple configuration option to set the “Mark as private” checkbox on by default. There seemed to be a lot of forum-based discussion on making this work for the Chrome extension, but it seemed no solution was immediately evident. So I decided to investigate, and found out what I could do. This post is as much an aide memoire as anything else.

The Chrome extensions can be administered by entering chrome://extensions into the address bar. This is what you can see for the Delicious Tools extension, when you have the Developer Mode expanded:

Chrome extension details

There are a couple of interesting things that we can see:

  • the ID of this extension isĀ gclkcflnjahgejhappicbhcpllkpakej, which is the same as part of the URL that points to the extension’s home page:
  • there’s a reference to the active view ‘background.html’, which, on inspection, contains a Javascript function addDelicious() which builds up the URL that will retrieve the Delicious page to save a bookmark

A find and grep later, I find this background.html component’s home:


It’s not just integration mechanisms that can be built in a loosely-coupled way. Applications built with HTTP, HTML, CSS and Javascript are also, almost by definition, beautifully loosely coupled; on inspecting the Javascript source in this file, we see:

   // Show delicious pop-up window
    addDelicious = function(conf) {
        var c = conf || {},
            doc = c.document || document,
            url = c.url || doc.location,
            title = c.title || doc.title,
            notes = c.notes || '',
            w = c.width || 550,
            h = c.height || 550,
            deliciousUrl = c.deliciousUrl || "",

        fullUrl = deliciousUrl + encodeURIComponent(url) + '&title=' + encodeURIComponent(title) + '&notes=' + encodeURIComponent(notes);

A simple addition of

fullUrl = fullUrl + "&share=no";

before the call to will add the query parameter “share=no” to the Delicious URL that is requested, resulting in the HTML form being rendered with the “Mark as private” checkbox already ticked.

Saving a bookmark, with private as default