CateforiesFragment.kt

private fun checkData() {
        if (view == null) return

        when (model.state) {
            CREATED -> {
                showProgress()
                model.setListener { checkData() }
                model.load()
            }

            PROGRESS -> {
                showProgress()
                model.setListener { checkData() }
            }

            ERROR -> {
                showError(R.string.unable_to_load) {
                    showProgress()
                    model.setListener { checkData() }
                    model.load()
                }
            }

            LOADED -> {
                adapter.addItems(model.data.sortedBy { it.name })
                showContent()

                adapter.setOnclickListener { category ->
                    
                }

            }
        }
    }