Coroutine in Fragment causing UIs not to render when navigating

Issue

I am using a coroutine inside a fragment to handle a network request. However when I navigate away to another fragment the UI from the next fragment is blank and nothing loads. I am using lifecycle scope so I thought the coroutine would be cancelled/cleaned up on destoyed but the only way the UI returns is if I comment out the coroutine.

 lifecycleScope.launch(context = Dispatchers.IO){
        if (pdfResponse != null) {
            try {
                file = getTempPdfFile(pdfResponse)
            } catch (e: Exception) {

            }
    }
}

  private fun getTempPdfFile(body: ResponseBody): File? {
    return try {
        val file = File.createTempFile("myfile", ".pdf")
        var inputStream: InputStream? = null
        var outputStream: OutputStream? = null
        try {
            val fileReader = ByteArray(4096)
            var fileSizeDownloaded: Long = 0
            inputStream = body.byteStream()
            outputStream = FileOutputStream(file)
            while (true) {
                val read: Int = inputStream.read(fileReader)
                if (read == -1) {
                    break
                }
                outputStream.write(fileReader, 0, read)
                fileSizeDownloaded += read.toLong()
            }
            outputStream.flush()
            return file
        } catch (e: IOException) {
            null
        } finally {
            inputStream?.close()
            outputStream?.close()
        }
    } catch (e: IOException) {
        null
    }
}

Can anyone help me diagnose the cause of this issue?

Solution

I created a suspend function in the viewmodel like this:

 suspend fun createPdfFile()  =
    withContext(Dispatchers.IO) {
        if (getPdfResponse() != null) {
            try {
                file = getPdfResponse()?.let { getTempPdfFile(it) }
            } catch (e: Exception) {
            }
        }
    }

Then in the view I called it using :

lifecycleScope.launch(Dispatchers.Main) {
   createPdfFile()
}

Answered By - AndroidDev123