Hey!! i need your help: i have a string with `data...

# compose-ios

[Eduardo Ruesta]

Hey!! i need your help:
i have a string with data:image/png;base64 so i created this fun :

fun String.cleanupImageString(): String {
    return this.replace("data:image/png;base64,", "")
        .replace("data:image/jpeg;base64,", "")
}

the i used this fun to convert to byteArray encoded to Image and convert to ImageBitmap:

@OptIn(ExperimentalEncodingApi::class)
actual fun String.decodeThumbnailImage(): ImageBitmap? {
    return try {
        val byteArray = Base64.decode(cleanupImageString())
        val skiaImage = Image.makeFromEncoded(byteArray)
        skiaImage.toComposeImageBitmap()
    } catch (e: Exception) {
        null
    }
}

but its returning null. Any idea? or another approach? thanks

[Csaba Szugyiczki]

Do you get an exception?
Debug it or add a logging line in the catch block to see what kind of Exception you might get.

[Eduardo Ruesta]

yea! let me catch the exception

[Eduardo Ruesta]

kotlin.IllegalArgumentException: Invalid symbol '
'(12) at index 76

[Eduardo Ruesta]

maybe its related to this method:

fun String.cleanupImageString(): String {
    return this.replace("data:image/png;base64,", "")
        .replace("data:image/jpeg;base64,", "")
}

[Csaba Szugyiczki]

My guess would be, based on the name of these methods, is that you are passing a decoded base64 byteArray to the makeFromEncoded method, which does not seem to be the right way to do this

[Csaba Szugyiczki]

@OptIn(ExperimentalEncodingApi::class)
actual fun String.decodeThumbnailImage(): ImageBitmap? {
    return try {
        val byteArray = cleanupImageString().toByteArray()
        val skiaImage = Image.makeFromEncoded(byteArray)
        skiaImage.toComposeImageBitmap()
    } catch (e: Exception) {
        null
    }
}

[Csaba Szugyiczki]

I would try something like this

[Eduardo Ruesta]

let me see

[Chrimaeon]

Or check the documentation of Image.makeFromEncoded so you don’t need to guess what it expects 😅

[Eduardo Ruesta]

fun makeFromEncoded(bytes: ByteArray): Image {
    Stats.onNativeCall()
    val ptr = interopScope {
        _nMakeFromEncoded(toInterop(bytes), bytes.size)
    }
    require(ptr != NullPointer) { "Failed to Image::makeFromEncoded" }
    return Image(ptr)
}

[Eduardo Ruesta]

i resolved! was something related to an extra spacing in the string

[Eduardo Ruesta]

thanks!