如何在MySQL数据库中存储对象的颜色数据？

Question

I have a situation in an iOS Swift app where the user can "customize the screen" by adding other views and/or changing the view's background color. When they tap save, I want to store the attributes of each object, as well as the parent view's background color to a MySQL database for later retrieval and reconstruction of the views. All data updates are done through PHP REST services.

I'm currently struggling with the color data for the background color. If I print() the color, I get something like "UIDeviceRGBColorSpace 0.866667 0.92549 1 1". I can also convert it to NSData with the following:

let data = NSKeyedArchiver.archivedDataWithRootObject(self.view.backgroundColor!)

However, in either case, I have no idea how to save the data to the database via PHP REST service or even what datatype I would use.

Am I going down the wrong path, altogether? Should I be doing something like grab the RGB values and Alpha and save those to 4 attributes in the database, or get the hex value and store that? Perhaps, there is yet a different approach that would be even more straight forward?

Answer 1

If you care about retaining all the information encoded in that NSColor / UIColor instance (original precise value in its original colour space which may not be RGB, calibration etc) and need to encode it as a string (instead of for instance binary blob, which is possible with MySQL too), you could use base64 encoding – send your server the colour in base64 encoded form, and decode it back when retrieving.

let color = NSColor.blackColor()
let data = NSKeyedArchiver.archivedDataWithRootObject(color)

// this can go in your database
let base64EncodedColorString = data.base64EncodedStringWithOptions([])

let decodedColorData = NSData(base64EncodedString: base64EncodedColorString, options: [])

NSKeyedUnarchiver.unarchiveObjectWithData(decodedColorData!)

This has the obvious downside that your server will have no clue about what that data encodes, so if you care about that, then getting the colour's RGB components and storing those as a string is probably the better option.