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I found four more bugs and two more feature requests to add to yesterday’s massive, minutiae-laden post about the Firefox 3 bookmarks manager:

Feature request: It would be awesome if you could sort your bookmarks by specific criteria, then make that sort order permanent. This would work exactly like the iTunes "Copy to playlist order" command. As in Firefox 2, you can approximate this by sorting your bookmarks alphabetically, moving them to a new folder, and moving them back. Then, even when you revert back to the "unsorted" view, the bookmarks stay in alphabetical order. Of course, this is way less necessary in Firefox 3, which can remember different sort orders for different bookmark folders, thus obviating the need to wrangle some folders into natural sort and others into alphabetical sort by brute force. Still, it’s a nice-to-have.

Feature request: The Views menu in the top toolbar should be broken out into separate Show and Sort menus. This is commonly accessed functionality, and it’s really annoying to have a two-item menu where each item contains around 10 sub-items which can only be accessed by clicking the menu, moving down, moving right, then moving down again to locate the desired item.

Bug: If you accidentally try to move an item to the same folder it’s
already in, it will simply disappear. Thank god for command-Z,
otherwise I would have accidentally deleted a folder with hundreds of
bookmarks.

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I’m working on a project estimating and tracking tool that we use internally here at Pathfinder. In that tool, each task is normally assigned to a specific user, however it’s not at all unusual for a task to live in the database for some time in an unassigned state. This leads to a lot of special case code along the lines of:

if task.user? then user.full_name else nil

This is a little bit annoying to continuously write, so I originally added a fake user into the database named “Unassigned”, and made that the default user for a new task. This works, and cleans up the code a bit, but it does seem a little hackish to have code actually depend on the existence of a specific database record. Also, as the data model got more complex, I wound up having to test for the Unassigned user later in the code, which is also becoming bothersome.

I decided to refactor the code using a variant of the Null Object pattern, which creates a specific class in code to represent the unassigned user, rather than an arbitrary database row. Unlike most of the standard Design Patterns, the Null Object pattern adapts quite usefully to a Ruby application.

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I’m a trigger-happy bookmarker, likely to command-D any page that seems like it could be of use in the future. I’ve learned to live with my affliction, but the Firefox 2 bookmark manager doesn’t exactly make my life easier. The problem? An interface that mimics the look and feel of a filesystem but deviates substantially from users’ expectations about how a filesystem operates.

With Firefox 3 now in its third beta release, I recently spent some time determining how its completely overhauled bookmark manager stacks up. The verdict? I see lots of cool new features, but it’s not a home run yet. I’m not sure whether the issues I saw were bugs, as-yet-unimplemented features, or poor design choices. Regardless, the Firefox 3 Beta 3 bookmark manager leaves several Firefox 2 annoyances unfixed and creates a couple of its own.

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Here’s your problem. You’re converting an existing project to Rails. The existing system has a database that, in the best case, doesn’t use Rails naming conventions. In the worst case, the old data is ill-structured, or uses a commercial database platform that you want to abandon.

Rather than deal with the ongoing pain of using Rails against the legacy database, you’ve decided to migrate the legacy data to a new database, using standard ActiveRecord constructs. Your next step is to migrate the data from old to new.

I’m making a few assumptions about your migration needs, hopefully they’ll be not very restrictive:

• You can connect to the existing database, either the live copy or (better) a recent snapshot.
• Although you’ll start migrating data during the development process, you’ll need to continue migrating new data right up until your final switchover.
• Performance is not a major issue for the migration.

My book, Professional Ruby On Rails, has more information on dealing with legacy databases.

After the jump, some ideas on how to use ActiveRecord to manage a data migration.

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This is something I consider an anti-pattern for parameter passing which describes both a specific data structure as well as the mechanisms surrounding its (ab)use.  It involves a way of modeling information where the semantics of the data may be dependent on disparate parts of the system.  There are other names I have given this pattern in the past, such as Great Big Bucket In The Sky, or Passing Parameters Under The Table, or Stuff In The Context Of Everything, or just Big Giant HashMap You get the idea.  I will describe a specific case, and then describe why I feel this approach is problematic.

First, however, a story that just so happens to be rooted in fact…

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