An example of using Lift's Wiring feature to build an invoice system.
Subtotal: subtotal
Tax Rate:
Taxable: taxable
Tax: Tax
Total: Total
The code for managing the invoice page is very simple.
We define the relationship between the data:
case class Line(guid: String, name: String, price: Double, taxable: Boolean) private object Info { val invoices = ValueCell(List(newLine)) val taxRate = ValueCell(0.05d) val subtotal = invoices.lift(_.foldLeft(0d)(_ + _.price)) val taxable = invoices.lift(_.filter(_.taxable). foldLeft(0D)(_ + _.price)) val tax = taxRate.lift(taxable) {_ * _} val total = subtotal.lift(tax) {_ + _} }
Next we create snippets to display the data:
def subtotal(in: NodeSeq) = WiringUI.asText(in, Info.subtotal) def taxable(in: NodeSeq) = WiringUI.asText(in, Info.taxable) def tax(in: NodeSeq) = WiringUI.asText(in, Info.tax, JqWiringSupport.fade) def total(in: NodeSeq) = WiringUI.asText(in, Info.total, JqWiringSupport.fade)
And hook the snippets into our view:
<div>Subtotal: <span class="lift:InvoiceWiring.subtotal">subtotal</span></div> <div>Tax Rate: <input class="lift:InvoiceWiring.taxRate"></div> <div>Taxable: <span class="lift:InvoiceWiring.taxable">taxable</span></div> <div>Tax: <span class="lift:InvoiceWiring.tax">Tax</span></div> <div>Total: <span class="lift:InvoiceWiring.total">Total</span></div>
And each time any of the cells changes, the display is automatically
updated.