Month: August 2009

Javascript insertAfter()

There is no Node.insertAfter() DOM function in Javascript, but it is clearly something that developers would like.

As the Gecko DOM Reference for Node.insertBefore() points out, this can easily be achieved with
parentDiv.insertBefore(nodeToInsert, nodeToInsertAfter.nextSibling);

If nodeToInsertAfter doesn’t have a next sibling, a NULL value will be returned and nodeToInsert will be inserted as the last child of parentDiv.

If you find it frustrating to type insertBefore when you want to insertAfter, that’s OK: you can add that function to the Object object:
Object.prototype.insertAfter = function (newNode) { this.parentNode.insertBefore(newNode, this.nextSibling); }

Now you can type:
nodeToInsertAfter.insertAfter(nodeToInsert)

Using Perl and PDF::API2 to Update PDF Properties and Metadata

What do you do when you have 600 PDF documents with titles in all caps, when you need the titles to be title-cased? I dreaded the thought of asking anyone to open each document and edit the titles by hand, not to mention fearing the typos that process might introduce.

For better or worse, here was my solution:

Sounds fast and easy, right? Well, there were a few hitches:
Continue reading Using Perl and PDF::API2 to Update PDF Properties and Metadata

Twitter Status IDs and Direct Message IDs

twitter-birdI recently created a Magic Eight Ball twitter-bot as a demo. Written in Python using the python-twitter API wrapper, it runs every 2 minutes and polls twitter for new replies (status updates containing @osric8ball) and direct messages (DMs) to osric8ball. If there are any, it replies with a random 8-Ball response.

Every status update and DM has an associated numeric ID. Initially, I stored the highest ID in a log file and used that when I polled twitter (i.e. “retrieve all replies and DMs with ID > highest ID”). However, I discovered that status updates and DMs apparently are stored in separate tables on twitter’s backend, as they have a separate set of IDs. Since the highest status ID was an order of magnitude larger than the highest DM ID, my bot completely ignored all DMs. This was not entirely obvious at first, as the IDs looked very similar, other than an extra digit: 2950029179 and 273876291.

My fix for this was to store both the highest status update ID and the highest DM ID is separate log files.

Another interesting twist: you have to be a follower of a user in order to send that user a DM. Continue reading Twitter Status IDs and Direct Message IDs