Don't change link text

app/views/customers/_actions.html.erb

@@ -1,4 +1,4 @@
-<%= link_to t(:label_appointment), "https://calendar.google.com/calendar/render?action=TEMPLATE&text=#{@customer.name}+-&details=#{ link_to t(:customer_details), "https://#{Setting.host_name}#{customer_path @customer.id}"}%0A#{@customer.primary_phone}&dates=#{Time.now.strftime("%Y%m%d")}T090000/#{Time.now.strftime("%Y%m%d")}T170000", target: :_blank %>
+<%= link_to t(:label_appointment), "https://calendar.google.com/calendar/render?action=TEMPLATE&text=#{@customer.name}+-&details=#{ link_to t(:customer_details), "https://#{Setting.host_name}#{customer_path @customer.id}"}%0A#{@customer.primary_phone}%3Cbr/%3E+&dates=#{Time.now.strftime("%Y%m%d")}T090000/#{Time.now.strftime("%Y%m%d")}T170000", target: :_blank, id: :appointment_link %>
 
 <br/>
 <br/>

app/views/estimates/_list.html.erb

@@ -2,6 +2,7 @@
 
   <% estimates.sort.reverse.each do |estimate| %>
     <div class="row">
+      <%= check_box_tag "estimate_ids[]", estimate.id, false,  onchange: "updateLink()", class: "estimate-checkbox" %>
       <b><%= link_to "##{estimate.doc_number}", estimate_path(estimate), target: :_blank %></b> <%= estimate.txn_date %>
     </div>
   <% end %>

app/views/invoices/_list.html.erb

@@ -12,7 +12,7 @@
 
     <% invoices.sort.reverse.each do |invoice| %>
       <div class="row">
-        <%= check_box_tag "invoice_ids[]", invoice.id, false, class: "invoice-checkbox" if invoices.count > 1 %>
+        <%= check_box_tag "invoice_ids[]", invoice.id, false,  onchange: "updateLink()", class: "invoice-checkbox" if invoices.count > 1 %>
         <b><%= link_to "##{invoice.doc_number}", invoice_path(invoice), target: :_blank %></b> <%= invoice.txn_date %>
       </div>
     <% end %>

assets/javascripts/application.js

@@ -0,0 +1,31 @@
+function updateLink() {
+  const linkElement = document.getElementById("appointment_link");
+  const regex = /((?:<br\/>|%3Cbr\/?%3E))([\s\S]*?)(&dates)/gi;
+  linkElement.href = linkElement.href.replace(regex, `$1${getSelectedDocs()}$3`);
+}
+
+function getSelectedDocs() {
+  const invoices = document.querySelectorAll('.invoice-checkbox');
+  const estimates = document.querySelectorAll('.estimate-checkbox');
+  
+  const invoiceIds = Array.from(invoices)
+      .filter(checkbox => checkbox.checked)
+      .map(checkbox => checkbox.value);
+
+  const estimateIds = Array.from(estimates)
+      .filter(checkbox => checkbox.checked)
+      .map(checkbox => checkbox.value);
+
+  let output = '';
+
+  for (const value of invoiceIds) {
+    output += `%0A<a href="${window.location.origin}/invoices/${value}">Invoice:%20${value}</a>%0A`;
+  }
+
+  for (const value of estimateIds) {
+    output += `%0A<a href="${window.location.origin}/estimates/${value}">Estimate:%20${value}</a>%0A`;
+  }
+  
+  // You can return the array or use it as needed
+  return output;
+}