Is method 'Settings.setDocumentSettingForKey()' asynchronous?

zimmer

Here is the code:

Settings.setDocumentSettingForKey(document, K, V)
document.save()

When this code fragment executed, the document became edited, the key has changed but not saved. I guess it was because the method save() executed before setDocumentSettingForKey().

zimmer

Is there anyway to execute save() right after settings settled?

kevgski

Maybe you could run a recursive function trying to get the key and then if it exists save? Something like this?

function saveAfterKey(key,limit) {
  if (Settings.documentSettingForKey(document, key)) {
    document.save()
  } else {
    setTimeout(()=>{saveAfterKey(key,limit)},limit)
  }
}

Where you would pass in the key and a limit in milliseconds for how frequently you want to check if the setting exists.

kevgski

You might want to add a counter or something such that it fails to save after some number of retires.

kevgski

Perhaps this

let sketch = require('sketch')
let Settings = sketch.Settings
let document = sketch.getSelectedDocument()
let UI = sketch.UI

let key = 'mytestkey2'
let value = 'hello'
Settings.setDocumentSettingForKey(document,key,value)

let counter = 0
saveAfterKey(key,300,30)

function saveAfterKey(key,throttle,numberOfAttempts) {
  if (counter > numberOfAttempts) {
    return UI.message("Unable to save")
  }
  
  if (Settings.documentSettingForKey(document, key)) {
    document.save()
    UI.message("Document Saved: " + counter)
  } else {
    counter = counter + 1
    setTimeout(()=>{saveAfterKey(key,throttle)},throttle)
  }
}

If you are reading/writing large amounts of data you might want to consider moving that out to a separate file instead of on the document.

zimmer

kevgski
Thanks, I tried setTimeout() to save document after 1000ms, it works. It seems like that setDocumentSettingForKey() is an asynchronous function? Is it possible to pass a callback function into that function in order to do something right after setting being saved?

kevgski

Short answer is no. The JS definition doesn't support a callback method. You can see how setDocumentSettingForKey is implemented here:
https://github.com/sketch-hq/SketchAPI/blob/develop/Source/settings/Settings.js#L141

Longer answer is not exactly. You are starting to head into cocoa territory. Many "callback functions" in cocoa rely on Key-Value Observing (KVO) or NSNotificationCenter.

__command.setValue_forKey_onDocument(stringifiedValue, key, documentData)

This bit of code is calling a private method on MSPluginCommand
https://github.com/abynim/Sketch-Headers/blob/master/Headers/MSPluginCommand.h#L51

Since it's a private method we don't now how exactly the data is getting saved to the document. If it behaves (subclasses) in a similar manner to NSUserDefaults then you could likely use KVO as described here:

https://stackoverflow.com/questions/10871860/nsuserdefaultsdidchangenotification-whats-the-name-of-the-key-that-changed

I also wouldn't be surprised if there is a NSNotification you could respond to but its terribly buggy in cocoascript as of late.