Merge pull request #891 from Kukks/pay-button-language

Allow language parameter in pay button endpoint

BTCPayServer/Controllers/PublicController.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using System.Web;
 using BTCPayServer.Filters;
 using BTCPayServer.Models;
 using BTCPayServer.Models.StoreViewModels;
@@ -58,7 +59,17 @@ namespace BTCPayServer.Controllers
                 RedirectURL = model.BrowserRedirect,
                 FullNotifications = true
             }, store, HttpContext.Request.GetAbsoluteRoot(), cancellationToken: cancellationToken);
+            if (string.IsNullOrEmpty(model.CheckoutQueryString))
+            {
                 return Redirect(invoice.Data.Url);
             }
+
+            var additionalParamValues = HttpUtility.ParseQueryString(model.CheckoutQueryString);
+            var uriBuilder = new UriBuilder(invoice.Data.Url);
+            var paramValues = HttpUtility.ParseQueryString(uriBuilder.Query);
+            paramValues.Add(additionalParamValues);
+            uriBuilder.Query = paramValues.ToString();
+            return Redirect(uriBuilder.Uri.AbsoluteUri);
+        }
     }
 }

BTCPayServer/Models/StoreViewModels/PayButtonViewModel.cs

@@ -30,6 +30,7 @@ namespace BTCPayServer.Models.StoreViewModels
         public string NotifyEmail { get; set; }
 
         public string StoreId { get; set; }
+        public string CheckoutQueryString { get; set; }
 
         // Data that influences Pay Button UI, but not invoice creation
         public string UrlRoot { get; set; }

BTCPayServer/Views/Stores/PayButton.cshtml

@@ -1,4 +1,4 @@
-@model PayButtonViewModel
+@model PayButtonViewModel
 @{
     Layout = "../Shared/_NavLayout.cshtml";
     ViewData.SetActivePageAndTitle(StoreNavPages.PayButton);
@@ -140,6 +140,24 @@
             Finally <i>Browser Redirect</i> defines where BtcPayServer will redirect customer after puchase is completed.
         </div>
     </div>
+     <h3>Advanced</h3>
+        <br />
+        <div class="row">
+            <div class="col-lg-7">
+                <div class="form-group">
+                    <label>Checkout Additional Query String</label>
+                    <input name="checkoutQueryString" type="text" class="form-control" placeholder="(optional)"
+                           v-model="srvModel.checkoutQueryString" v-on:change="inputChanges"
+                           :class="{'is-invalid': errors.has('checkoutQueryString') }">
+                    <small class="text-danger">{{ errors.first('checkoutQueryString') }}</small>
+                </div>
+            </div>
+            <div class="col-lg-5">
+                <br />
+                This parameter allows you to specify additional query string paramters that should be appended to the checkout page once the invoice is created. For example, <kbd>lang=da-DK</kbd> would load the checkout page in Danishby default.
+                
+            </div>
+        </div>
     <hr />
     <h3>Generated code</h3>
     <div class="row" v-show="!errors.any()">

BTCPayServer/wwwroot/paybutton/paybutton.js

@@ -26,7 +26,7 @@ function esc(input) {
 }
 
 Vue.use(VeeValidate);
-const dictionary = {
+var dictionary = {
     en: {
         attributes: {
             price: 'Price', checkoutDesc: 'Checkout Description', orderId: 'Order Id',
@@ -97,6 +97,9 @@ function inputChanges(event, buttonSize) {
     if (srvModel.notifyEmail) {
         html += addinput("notifyEmail", srvModel.notifyEmail);
     }   
+    if (srvModel.checkoutQueryString) {
+        html += addinput("checkoutQueryString", srvModel.checkoutQueryString);
+    }
 
     html += '\n    <input type="image" src="' + esc(srvModel.payButtonImageUrl) + '" name="submit" style="width:' + width +
         '" alt="Pay with BtcPay, Self-Hosted Bitcoin Payment Processor">';