Adding strings localization files from a server

Question

We are building an application with dynamic data that we wish to localize. We know how to localize strings in iOS and Android but in this case the data will be downloaded dynamically from the server so we will need to download the localization files dynamically.

Usually we store the strings files inside language folders. how can we do that when the file is coming from the server?

Kuykendall

Do you have any success with this? I'm standing in front of the same problem. Is it possible to use a downloaded Localizeable.strings instead of app bundled .strings file? – Indiana

Hi, I am using @Ole Begemann answer below and it works great – Kuykendall

Answer 1

how can we do that when the file is coming from the server?

You can't because the app bundle is not writable on iOS devices.

There is, however, NSLocalizedStringFromTableInBundle(), which lets you specify a different bundle from which you can load the .strings file. I haven't tried but I suppose this bundle can also reside in your app's Documents or Library folder.

Rappel

Here is what I did: create a bundle with Xcode and then move it into your application documents directory (in the simulator for instance), make sure you remove it from the project navigator in Xcode, and create within it a en.lproj subdirectory with a Localizable.strings file. Then you can programmatically create a NSBundle with the appropriate path, and use the -[NSBundle localizedStringForKey:value:table:] to retrieve the content of the strings files. – Andros

Last comment is a bit strange... All you need to do is to create a folder FOLDER_NAME.bundle with help of fileManager in Library folder at runtime. Then put your custom_name.strings files in language appropriate folders (exp: en.lproj). Than you can use your .strings files with NSLocalizedStringFromTableInBundle(). – Checkers

Actually, it doesn't work truly dynamically :( App loads those .strings files only on next launch. If you need true dynamic adding of .strings files, look here – Checkers

Came across this thread when attempting to implement dynamic localization as well - I'm finding that I can edit a custom .strings file in my own custom bundle (which I've placed in the Documents directory) and while NSLocalizedStringFromTableInBundle() doesn't work from the simulator or from unit tests for newly added content to the .strings file (until the next application load as stated), I can use NSLocalizedStringFromTableInBundle() to access new content immediately from the device (tested and confirmed so far on iPad3/iOS7 and iPadAir/iOS8). – Ruelas

Answer 2

Yes, it's possible, but not using standard means. Check this github repository for simple and elegant solution.

It uses .json file which contains localization info and may be downloaded from server. All controllers need to subscribe to notifications sent by localization class and implement a method responsible for (re-)setting all texts in view.

Inamorata

Answer 3

Create a custom bundle in the documents directory.

Looking at the Apple documentation for Text: https://developer.apple.com/documentation/swiftui/text

The SwiftUI text view initializer accepts a bundle parameter.

1 - We need to create a custom bundle. This can be done using the convenience initializer with a URL to our custom bundle:
convenience init?(url: URL)
https://developer.apple.com/documentation/foundation/bundle/1409352-init

2 - place programmatically the language folders in it ( and add the strings files inside).

The languages available on device can be found in:
Bundle.main.localizations. which returns an array such as:
["de", "en", "Base", "en-US", "de-DE"]

You need to take this array and create the corresponding folders "de.proj", "en.proj" etc. in your custom bundle.
Then add the .strings files with the key - translated value pairs such as ex in en.proj the assets.strings with:
`"Titlekey54" = "Localised title English";

This will show "Localised title English" in your UI if you selected English in settings and you passed the correct bundle to the Text initializer.

NB: If you pass a variable you need to pass a LocalizedStringKey type or it will not localise automatically

(from the apple docs)

// a string variable will not be localized
Text(writingImplement)

// ...unless you explicitly convert it to a localized string key.
Text(LocalizedStringKey(writingImplement))

In this case I created a class to hold the current custom bundle and a setter to change it when the user changes language in the app.

The code to create the directories is a bit complicated and I don't want to make this post too long. I will try to make my code available later on.

I made it to work in this small prototype app:
https://github.com/multitudes/MyLocalisationTestApp

Also, to create custom bundles on disk I found some good resource in this repo. 👍🏻 https://github.com/bharathi91/NextLevelLocalization

Immanuel

Answer 4

What our company was thinking about is to send the language of the device and the last time the language was updated to the server. Then, the server checks the language in the database, and if the language exists, it sends, if not, it will send english list of translations by default. The response consists of the list of array of key: value data, and the last time it was updated, which is sent every time the app launches. So mobile should cache the list of translations, and just use the data from cache. In this case you do not need to use xml file of localized, and since the server is checking the last time it was updated, you do not have to refresh the key value data everytime, but only the data which you for from the server.

Kenlee