Enforce stock max en 0 min for amount of products in orders

Fixes #48

app/assets/javascripts/orders.js.coffee

@@ -9,16 +9,36 @@ ready = ->
     increment($(this), -1)
 
   $('.form_row').each((index, row) ->
-    disIfNec(row)
+    updateInput(row, false)
-    $(row).on('input', recalculate)
+    $(row).on('input', ->
+      updateInput(row)
+    )
   )
 
   recalculate()
 
+
+
+# Validate input, and then update
+updateInput = (row, useRecalculate = true)->
+  cell = row.querySelector("input")
+  if ! cell.validity.valid
+    if(parseInt(cell.value) > parseInt(cell.max))
+      cell.value = parseInt(cell.max)
+    else
+      cell.value = 0
+
+  # Disable buttons if necessary
+  disIfNec(row)
+
+  if useRecalculate
+    recalculate();
+
+
 disIfNec = (row) ->
   counter = parseInt($(row).find('.row_counter').val())
   $(row).find('.btn-dec').prop('disabled', counter == 0);
-  $(row).find('.btn-inc').prop('disabled', counter == parseInt($(row).find('.stock').val()))
+  $(row).find('.btn-inc').prop('disabled', counter == parseInt($(row).find('.row_counter').attr('max')))
 
 recalculate = () ->
   value = ($(row).find('.row_counter').val() * $(row).find('.price').val() for row in $('.form_row')).reduce (a, b) -> a+b
@@ -29,12 +49,12 @@ increment = (button, n) ->
 
   # Fix the counter
   counter = $(row).find('.row_counter')
-  counter.val(parseInt(counter.val()) + n)
+  value = parseInt(counter.val())
+  # Apparently CoffeeScript doesn't support ?:
+  value =  if isNaN(value) then 0 else value
+  counter.val(value + n)
 
-  # Disable buttons if necessary
+  updateInput(row[0])
-  disIfNec(row)
-
-  recalculate()
 
 $(document).ready(ready)
 $(document).on('page:load', ready)

app/views/order_items/_order_item.html.erb

@@ -9,7 +9,7 @@
         <%= content_tag :span, product.name %>
         <%= content_tag :small, euro(product.price) %>
         </h4>
-        <%= f.counter :count, max: 1000, skip_label: true, wrapper_class: "input-group", class: "row_counter" %>
+        <%= f.counter :count, max: product.stock, min:0, skip_label: true, wrapper_class: "input-group", class: "row_counter" %>
         <%= f.fields_for :product do |product| %>
           <%= product.hidden_field :price_cents, class: :price %>
           <%= product.hidden_field :stock, class: :stock %>