This is probably the world's first JavaScript for Automation script written in Literate CoffeeScript. Yes, the very file you are reading is an executable script. To run it, see the instructions at bottom.

Helvetica has haunted me again. As you might know in my Yosemite System Font Patcher project, for me the Helvetica font feels too ancient.

Now, I am creating a presentation using Keynote. With its default theme, all slide texts are in Helvetica Neue. And there are 12 master slides to edit.

Yeah, just 12 slides, that's not much, I could have done it manually, but I was too lazy. So I come to my friend, JavaScript for Automation.

I opened the Script Editor Dictionary and looked into Keynote. I found out that:

• The Keynote Application contains documents (that is opening in the app).
• Each Document contains masterSlides.
• Each MasterSlide contains textItems.
• Each TextItem has the objectText property, which is a RichText.
• The RichText contains the font property, which is the PostScript name of the font.

For the presentation I'm working on, I think I'll use Avenir Next again. We first need to specify the PostScript name. We can obtain the PostScript name using the Font Book application.

TARGET_FONT = 'AvenirNext-Regular'

Now, let's get the current document from the Keynote application.

document = Application('Keynote').documents[0]

And for each master slide in it, we will replace the fonts in each text item.

for slide in document.masterSlides
  for textItem in slide.textItems
    textItem.objectText.font = TARGET_FONT

Well, it's that simple.

First, install CoffeeScript using npm.

npm install -g coffee-script

Then compile this README.litcoffee into JavaScript and pass it to osascript command line tool.

coffee -cp README.litcoffee | osascript -l JavaScript