Allow doing math in price field for each markups

app/views/line_items/_line_item_fields.html.erb

@@ -23,9 +23,10 @@
   </td>
 
   <td data-label="<%= t :label_price %>">
-    <%= f.number_field :unit_price,
+    <%= f.text_field :unit_price,
-          step: 0.01,
           class: "price-field",
+          inputmode: "decimal",
+          autocomplete: "off",
           no_label: true,
           disabled: readonly %>
   </td>

assets/javascripts/blur.js

@@ -0,0 +1,33 @@
+function evaluateMathExpression(expr) {
+  if (!expr) return null;
+
+  // allow only digits, decimal, operators, parentheses, spaces
+  if (!/^[0-9+\-*/().\s]+$/.test(expr)) {
+    return null;
+  }
+
+  try {
+    return Function('"use strict"; return (' + expr + ')')();
+  } catch {
+    return null;
+  }
+}
+
+document.addEventListener("blur", function(e) {
+
+  if (!e.target.classList.contains("price-field")) return;
+
+  const field = e.target;
+  const value = field.value.trim();
+
+  const result = evaluateMathExpression(value);
+
+  if (result !== null && !isNaN(result)) {
+    field.value = Number(result).toFixed(2);
+  }
+
+  if (typeof updateLineItemTotals === "function") {
+    updateLineItemTotals();
+  }
+
+}, true);

lib/redmine_qbo_line_items/hooks/view_hook_listener.rb

@@ -19,6 +19,7 @@ module RedmineQboLineItems
           javascript_include_tag( 'nested_form_controller', plugin: :redmine_qbo_lineitems),
           javascript_include_tag("line_items", plugin: :redmine_qbo_lineitems),
           javascript_include_tag("autocomplete", plugin: :redmine_qbo_lineitems),
+          javascript_include_tag("blur", plugin: :redmine_qbo_lineitems),
           stylesheet_link_tag("line_items", plugin: :redmine_qbo_lineitems)
         ])
       end