In Mac OS X Yosemite, the automation tools incorporate a new scripting language: JavaScript. Since I use some AppleScript with Alfred for resizing windows, I decided to give it a try.
Here is the original:
tell application "Finder"
set b to bounds of window of desktop
set width to item 3 of b
set height to item 4 of b
end tell
set name to name of ¬
(info for (path to frontmost application))
set q to "{query}" --- the query variable from Alfred
tell application name
activate
if q is "f" then
set nb to ¬
{0, 0, width, height}
else if q is "m" then
set nb to ¬
{width/8, height/8, width/1.125, height/1.125}
else if q is "tr" then
set nb to {width/2, 0, width, height/2}
else if q is "tl" then
set nb to {0, 0, width/2, height/2}
else if q is "th" then
set nb to {0, 0, width, height/2}
else if q is "r" then
set nb to {width/2, 0, width, height}
else if q is "l" then
set nb to {0, 0, width/2, height}
else if q is "br" then
set nb to {width/2, height/2, width, height}
else if q is "bl" then
set nb to {0, height/2, width/2, height}
else if q is "bh" then
set nb to {0, height/2, width, height}
else if q is "h" then
set nb to {width/4, 0, width/1.25, height}
end if
end tell
set bounds of first window to nbAnd here is the same script rewritten in JavaScript:
finder = Application("Finder")
bounds = finder.desktop.window.bounds()
width = bounds["width"]
height = bounds["height"]
query = "{query}" // the query variable from Alfred
boundsMap = {
"f": {"x":0, "y":0, "width":width, "height":height},
"m": {"x":width/8, "y":height/8,
"width":width/1.3, "height":height/1.3},
"tr": {"x":width/2, "y":0, "width":width, "height":height/2},
"tl": {"x":0, "y":0, "width":width/2, "height":height/2},
"th": {"x":0, "y":0, "width":width, "height":height/2},
"r": {"x":width/2, "y":0, "width":width/2, "height":height},
"l": {"x":0, "y":0, "width":width/2, "height":height},
"br": {"x":width/2, "y":height/2, "width":width, "height":height},
"bl": {"x":0, "y":height/2, "width":width/2, "height":height},
"bh": {"x":0, "y":height/2, "width":width, "height":height/2},
"h": {"x":width/4, "y":0, "width":width/2, "height":height},
}
SystemEvents = Application("System Events")
appName = SystemEvents.processes.whose({ frontmost: true })[0].name()
app = Application(appName)
app.windows[0].bounds = boundsMap[query]There are a couple things to note here. First, the JavaScript used is not standard. Some syntax is not required (var, ;), while other syntax and globals are built into the language: .whose({ frontmost: true }, console.log, $, etc. The API for interacting with objects is also different from traditional JavaScript. For example, properties are accessed like methods, e.g. .name(), while setters still use the = assignment. Element arrays are an exception—they can be accessed like regular javascript properties (Mail.windows), but also have syntactic sugar as well: Mail.windows.byName('New Message') or Mail.windows.byId(412). There is a global object called ObjectSpecifier which identifies an object or property’s class: ObjectSpecifier.classOf(Mail.inbox).
The script performs the exact same function, but the JavaScript is easier to read and understand, in my opinion. I believe there are two reasons for this: the syntax is clear and the use of a data structure is intuitive. With AppleScript, it took me some time to peruse the documentation to even understand how to create a hash/map as a comparison.
I’m interested in seeing whether this becomes the preferred option for automation in Mac OS or if it is just an alternative. For now you can learn more about JavaScript automation in Yosemite at the current (and so far, only) documentation.