The blog of dlaa.me

Posts from November 2018

A picture is worth a thousand words [A small script to update contact photos on iOS]

I'm always looking for new ways to develop code. My latest adventure was writing a script to update contact photos on iOS for a prettier experience in the Messages app conversation list. The script is called update-ios-contact-images.js and it runs in Scriptable, a great app for interacting with the iOS platform from JavaScript. The idea is:

There are various conditions where Apple iOS can't (or won't) synchronize Contact photos between iPhone/iPad devices. If you're in this situation and want it to "just work", you can configure each device manually. Or you can run this script to do that for you.

update-ios-contact-images.js takes a list of email addresses and optional image links and sets the photo for matching contacts in your address book. If an image link is provided, it's used as-is; if not, the Gravatar for that email address is used instead.

You can find more in the update-ios-contact-images.js repository on Github, but the code is short enough that I've included it below.

Notes

  • As I said on Twitter, this was the first meaningful programming project I did completely on iPad (and iPhone). Research, prototyping, coding, debugging, documentation, and posting to GitHub were all done on an iOS device (using a Bluetooth keyboard at times). The overall workflow has some rough edges, but many of the pieces are there today to do real-world development tasks.
  • I'm accustomed to using JavaScript Promises directly, but took this opportunity to try out async and await. The latter are definitely easier to use - and probably easier to understand (though the syntax error JavaScriptCore gives for using await outside an async function is not obvious to me). However, the lack of support for "parallelism" by async/await means you still need to know about Promises and be comfortable using helpers like Promise.all (so I wonder how much of a leaky abstraction this ends up being).
    • Yes, I know JavaScript is technically single-threaded in this context; that's why I put the word "parallelism" in quotes above. :)

Code

// update-ios-contact-images
// A Scriptable (https://scriptable.app/) script to update contact photos on iOS
// Takes a list of email accounts and image URLs and assigns each image to the corresponding contact
// https://github.com/DavidAnson/update-ios-contact-images

// List of email accounts and images to update
const accounts = [
  {
    email: "test1@example.com"
    // No "image" property; uses Gravatar
  },
  {
    email: "test2@example.com",
    image: "https://example.com/images/test2.jpg"
  }
];

// MD5 hash for Gravatar (see https://github.com/blueimp/JavaScript-MD5 and https://cdnjs.com/libraries/blueimp-md5)
eval(await (new Request("https://cdnjs.cloudflare.com/ajax/libs/blueimp-md5/2.10.0/js/md5.min.js")).loadString());

// Load all address book contacts
const contacts = await Contact.all(await ContactsContainer.all());

// For all accounts...
await Promise.all(accounts.map(account => {
  // Normalize email address
  const emailLower = account.email.trim().toLowerCase();
  // For all contacts with that email...
  return Promise.all(contacts.
    filter(contact => contact.emailAddresses.some(address => address.value.toLowerCase() === emailLower)).
    map(async contact => {
      // Use specified image or fallback to Gravatar (see https://en.gravatar.com/site/implement/images/)
      const url = account.image || `https://www.gravatar.com/avatar/${md5(emailLower)}`;
      // Load image from web
      contact.image = await (new Request(url).loadImage());
      // Update contact
      Contact.update(contact);
      console.log(`Updated contact image for "${emailLower}" to "${url}"`);
    }));
}));

// Save changes
Contact.persistChanges();
console.log("Saved changes");