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URI Resolver

CE.SDK gives you full control over how Uris should be resolved. To register a custom resolver, use setUriResolver and pass in a function implementing your resolution logic. If a custom resolver is set, any Uri (both relative and absolute) requested by the engine is passed through the resolver. The Uri your logic returns is then fetched by the engine. The resolved Uri is just used for the current request and not stored. If, and only if, no custom resolver is set, the engine performs the default behaviour: absolute uri objects are unchanged and relative objects are turned into android asset Uris.

We can preview the effects of setting a custom Uri resolver with the function fun getAbsoluteUri(uri: Uri): Uri.

Before setting a custom Uri resolver, the default behavior is as before: absolute Uri is unchanged and relative is turned into android asset Uri.

// This will return uri to "banana.jpg" asset file
engine.editor.getAbsoluteUri(uri = Uri.parse("banana.jpg"))
// This will return uri to remote resource "https://example.com/orange.png"
engine.editor.getAbsoluteUri(uri = Uri.parse("https://example.com/orange.png"))

To show that the resolver can be fairly free-form, in this example we register a custom Uri resolver that replaces all .jpg images with our company logo.

Note: you can still access the default Uri resolver by calling fun defaultUriResolver(uri: Uri): Uri.

// Replace all .jpg files with the IMG.LY logo!
engine.editor.setUriResolver {
    if (it.toString().endsWith(".jpg")) {
        Uri.parse("https://img.ly/static/ubq_samples/imgly_logo.jpg")
    } else {
        engine.editor.defaultUriResolver(it)
    }
}

Given the same uri as earlier, the custom resolver transforms it as specified. Note that after a custom resolver is set, uris that the resolver does not transform remain unmodified thanks to defaultUriResolver.

    // The custom resolver will return a path to the IMG.LY logo because the given path ends with ".jpg".
    // This applies regardless if the given path is relative or absolute.
    engine.editor.getAbsoluteUri(uri = Uri.parse("banana.jpg"))


    // The custom resolver will not modify this path because it ends with ".png".
    engine.editor.getAbsoluteUri(uri = Uri.parse("https://example.com/orange.png"))


    // Because a custom resolver is set, relative paths that the resolver does not transform remain unmodified!
    engine.editor.getAbsoluteUri(uri = Uri.parse("/orange.png"))

To remove a previously set custom resolver, call the function with a null value. The Uri resolution is now back to the default behavior.

    // Removes the previously set resolver.
    engine.editor.setUriResolver(null)


    // Since we've removed the custom resolver, this will return
    // Uri.Asset("banana.jpg") like before.
    engine.editor.getAbsoluteUri(uri = Uri.parse("banana.jpg"))

Full Code

Here’s the full code:

import android.net.Uri
import kotlinx.coroutines.*
import ly.img.engine.*


fun uriResolver(
    license: String,
    userId: String,
) = CoroutineScope(Dispatchers.Main).launch {
    val engine = Engine.getInstance(id = "ly.img.engine.example")
    engine.start(license = license, userId = userId)
    engine.bindOffscreen(width = 100, height = 100)


    // This will return uri to "banana.jpg" asset file
    engine.editor.getAbsoluteUri(uri = Uri.parse("banana.jpg"))
    // This will return uri to remote resource "https://example.com/orange.png"
    engine.editor.getAbsoluteUri(uri = Uri.parse("https://example.com/orange.png"))


    // Replace all .jpg files with the IMG.LY logo!
    engine.editor.setUriResolver {
        if (it.toString().endsWith(".jpg")) {
            Uri.parse("https://img.ly/static/ubq_samples/imgly_logo.jpg")
        } else {
            engine.editor.defaultUriResolver(it)
        }
    }


    // The custom resolver will return a path to the IMG.LY logo because the given path ends with ".jpg".
    // This applies regardless if the given path is relative or absolute.
    engine.editor.getAbsoluteUri(uri = Uri.parse("banana.jpg"))


    // The custom resolver will not modify this path because it ends with ".png".
    engine.editor.getAbsoluteUri(uri = Uri.parse("https://example.com/orange.png"))


    // Because a custom resolver is set, relative paths that the resolver does not transform remain unmodified!
    engine.editor.getAbsoluteUri(uri = Uri.parse("/orange.png"))


    // Removes the previously set resolver.
    engine.editor.setUriResolver(null)


    // Since we've removed the custom resolver, this will return
    // Uri.Asset("banana.jpg") like before.
    engine.editor.getAbsoluteUri(uri = Uri.parse("banana.jpg"))


    engine.editor.setUriResolver { uri ->
        val path = uri.path
        if (uri.host == "localhost" && path != null && path.startsWith("/scenes") && !path.endsWith(".scene")) {
            // Apply custom logic here, e.g. redirect to a different server
        }
        engine.editor.defaultUriResolver(uri)
    }


    engine.stop()
}