Hiding Payment Options for Free Tickets in Open Event Android
Payment Options spinner allows the user to pick any convenient payment method for an order however, Payment Options should not be shown if the total worth of order is zero or the event is free. This blog post will guide you on how its implemented in Open Event Android. Following are the sequence of steps that are followed for this
- Allow the user to select tickets and their quantity
- Use DAO method to get the prices of the tickets selected by the user
- Iterate through the List and keep storing the prices
- Display Payment Selector for order with the total amount greater than zero
Given below is DAO method to get the list of prices for different tickets. The method makes a simple select statement and returns price attribute of tickets with id in passed ids. A single list of float is returned by the function.
| @Query(“SELECT price from Ticket WHERE id in (:ids)”) fun getTicketPriceWithIds(ids : List<Int>): Single<List<Float>> |
This DAO method is then exposed to other parts (ViewModels, Fragments) using service layer class method getTicketPriceWithIds which just makes calls to DAO method and return the result provided by it. Service classes are used for separation of concerns.
| fun getTicketPriceWithIds(ids: List<Int>): Single<List<Float>> { return ticketsDao.getTicketPriceWithIds(ids) } |
When a list of tickets and their quantity is specified by the user the prices of the ticket are fetched using the above-explained methods. These are then stored it in a List of pair with the first element being ticket id and second its quantity.
| fun updatePaymentSelectorVisibility(ticketIdAndQty: List<Pair<Int, Int>>?) { val ticketIds = ArrayList<Int>() ticketIdAndQty?.forEach { if (it.second > 0) ticketIds.add(it.first) } compositeDisposable.add(ticketService.getTicketPriceWithIds(ticketIds) .subscribeOn(Schedulers.io()) .observeOn(AndroidSchedulers.mainThread()) .subscribe({ var total = 0.toFloat() it?.forEach { if (it.toFloat() > 0) total += it.toFloat() } paymentSelectorVisibility.value = total != 0.toFloat() }, { Timber.e(it, “Error Loading tickets!”) })) } |
The above method controls the visibility boolean for payment selector, it essentially iterates over the List<Pair<Int, Int>> and add all the ticket id to a temporary list if quantity for that ticket is greater than zero after this prices for the tickets in temporary list is fetched and sum total is calculated. If this total is greater than zero the visibility boolean is set else reset.
Finally an observable is set on this boolean which automatically updates the UI whenever boolean changes accordingly.
| attendeeFragmentViewModel.paymentSelectorVisibility.observe(this, Observer { if (it !=null && it) { rootView.paymentSelector.visibility = View.VISIBLE } else { rootView.paymentSelector.visibility = View.GONE } }) |