Resources generation in Kotlin Multiplatform.

// build.gradle.kts (project)

buildscript {
    dependencies {
        classpath("io.github.skeptick.libres:gradle-plugin:1.2.2")
    }
}

// build.gradle.kts (module)

plugins {
    id("io.github.skeptick.libres")
}

libres {
    generatedClassName = "MainRes" // "Res" by default
    generateNamedArguments = true // false by default
    baseLocaleLanguageCode = "ru" // "en" by default
    camelCaseNamesForAppleFramework = false // false by default
}

// build.gradle.kts (module)

kotlin {
    commonMain {
        dependencies {
            implementation("io.github.skeptick.libres:libres-compose:1.2.2")
        }
    }
}

This artifact provides painterResource function that can be used to get Painter from io.github.skeptick.libres.Image in common code.

• Android, JVM, iOS, MacOS and JS in Kotlin Multiplatform projects.
• Pure Android or JVM projects with Kotlin.

‼️ Also you need to use CocoaPods and CocoaPods Gradle plugin to export images to iOS application.
If you aren't reusing images in iOS then this condition is optional.

⚠️ Cocoapods caches list of resource directories when pod install is called, so bundles directory must exist at this time. You won't see this issue if your .podspec is in .gitignore in any case it's best to be safe with this hook in your Podfile.

Suppose your Kotlin Framework is added like this:

pod 'umbrella', :path => '../common/umbrella/umbrella.podspec'

Then this hook will look like this:

pre_install do |installer|
  FileUtils.mkdir_p(installer.sandbox.root.to_s + '/../../common/umbrella/build/generated/libres/apple/libres-bundles')
end

Resources must be stored in {yourSourceSetName}/libres

Multiplatform:

├── commonMain
│   ├── kotlin
│   └── libres
│       ├── images
│       │   ├── vector_image.svg
│       │   └── raster_image.png
│       └── strings
│           ├── strings_en.xml
│           └── strings_ru.xml

Android or JVM:

├── main
│   ├── java
│   └── libres
│       ├── images
│       │   ├── vector_image.svg
│       │   └── raster_image.png
│       └── strings
│           ├── strings_en.xml
│           └── strings_ru.xml

Strings are stored in usual for Android form in xml files.
The file postfix must contain language code for which these strings are intended. E.g.: my_app_strings_en.xml
For each of languages you can create several files and they will be merged during compilation.

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="simple_string">Hello!</string>
    <string name="string_with_arguments">Hello ${name}!</string>
    <plurals name="plural_string">
        <item quantity="one">resource</item>
        <item quantity="other">resources</item>
    </plurals>
</resources>

Kotlin:

MainRes.string.simple_string
MainRes.string.string_with_arguments.format(name = "John")
MainRes.string.plural_string.format(5)

Swift:

MainRes.shared.string.simple_string
// or MainRes.shared.string.simpleString if `camelCaseNamesForAppleFramework` enabled

Note In this example MainRes.string.simple_string will return a string, so for better localization support it's not recommended to store the value. Get it directly at the place where it's displayed in UI. This seems familiar but ability to work directly with strings instead of resource IDs can be misused.

Supported formats:

• PNG
• JPG
• WEBP (Android 4.3+, iOS 14+)
• SVG (iOS 13+)

For Android SVGs are converted to vector drawable, for other platforms they copied as is.

The image filename can contain modifiers in parentheses listed through underscores.

orig

Used for iOS. Marks image as Original (similar to Render As: Original Image in XCode Assets Manager). Recommended for multicolor images.

size

Applies to bitmaps. Reduces image resolution to specified size.

• For Android generate images from mdpi to xxxhdpi (where mdpi is 1:1 in pixels to specified size)
• For iOS generate images from @1x to @3x (where @1x is 1:1 in pixels to specified size)
• For JVM and JS a single image of specified size is generated.

Filename examples:

some_hd_image_(100).jpg
app_logo_(orig).svg
my_colorful_bitmap_(orig)_(150).png

Kotlin:

MainRes.image.some_hd_image
MainRes.image.app_logo
MainRes.image.my_colorful_bitmap

Swift:

MainRes.shared.image.some_hd_image
// or MainRes.shared.image.someHdImage if `camelCaseNamesForAppleFramework` enabled