Do error catching etc.

app/Http/Middleware/InterestingMessage.php

@@ -26,6 +26,7 @@ namespace FireflyIII\Http\Middleware;
 use Closure;
 use FireflyIII\Models\Account;
 use FireflyIII\Models\Bill;
+use FireflyIII\Models\TransactionCurrency;
 use FireflyIII\Models\TransactionGroup;
 use FireflyIII\Models\TransactionJournal;
 use FireflyIII\Models\Webhook;
@@ -68,6 +69,10 @@ class InterestingMessage
             Preferences::mark();
             $this->handleWebhookMessage($request);
         }
+        if ($this->currencyMessage($request)) {
+            Preferences::mark();
+            $this->handleCurrencyMessage($request);
+        }
 
         return $next($request);
     }
@@ -221,10 +226,57 @@ class InterestingMessage
     private function webhookMessage(Request $request): bool
     {
         // get parameters from request.
-        $billId  = $request->get('webhook_id');
+        $webhookId = $request->get('webhook_id');
+        $message   = $request->get('message');
+
+        return null !== $webhookId && null !== $message;
+    }
+
+    /**
+     * @param Request $request
+     *
+     * @return bool
+     */
+    private function currencyMessage(Request $request): bool
+    {
+        // get parameters from request.
+        $code    = $request->get('code');
         $message = $request->get('message');
 
-        return null !== $billId && null !== $message;
+        return null !== $code && null !== $message;
+    }
+
+    private function handleCurrencyMessage(Request $request): void
+    {
+        // params:
+        // get parameters from request.
+        $code    = $request->get('code');
+        $message = $request->get('message');
+
+        /** @var TransactionCurrency $webhook */
+        $currency = TransactionCurrency::whereCode($code)->first();
+
+        if (null === $currency) {
+            return;
+        }
+        if ('enabled' === $message) {
+            session()->flash('success', (string)trans('firefly.currency_is_now_enabled', ['name' => $currency->name]));
+        }
+        if ('enable_failed' === $message) {
+            session()->flash('error', (string)trans('firefly.could_not_enable_currency', ['name' => $currency->name]));
+        }
+        if ('disabled' === $message) {
+            session()->flash('success', (string)trans('firefly.currency_is_now_disabled', ['name' => $currency->name]));
+        }
+        if ('disable_failed' === $message) {
+            session()->flash('error', (string)trans('firefly.could_not_disable_currency', ['name' => $currency->name]));
+        }
+        if ('default' === $message) {
+            session()->flash('success', (string)trans('firefly.new_default_currency', ['name' => $currency->name]));
+        }
+        if ('default_failed' === $message) {
+            session()->flash('error', (string)trans('firefly.default_currency_failed', ['name' => $currency->name]));
+        }
     }
 
     /**

public/v1/js/ff/currencies/index.js

@@ -45,8 +45,13 @@ function setDefaultCurrency(e) {
             'Content-Type': 'application/json',
             'X-CSRF-Token': $('meta[name="csrf-token"]').attr('content'),
         },
+        error: function () {
+            window.location = redirectUrl + '?message=default_failed&code=' + currencyCode;
+        },
+        success: function () {
+            window.location = redirectUrl + '?message=default&code=' + currencyCode;
+        }
     });
-    window.location = redirectUrl + '?message=default&code=' + currencyCode;
     return false;
 }
 
@@ -66,8 +71,13 @@ function enableCurrency(e) {
             'Content-Type': 'application/json',
             'X-CSRF-Token': $('meta[name="csrf-token"]').attr('content'),
         },
+        error: function () {
+            window.location = redirectUrl + '?message=enable_failed&code=' + currencyCode;
+        },
+        success: function () {
+            window.location = redirectUrl + '?message=enabled&code=' + currencyCode;
+        }
     });
-    window.location = redirectUrl + '?message=enabled&code=' + currencyCode;
     return false;
 }
 
@@ -76,7 +86,7 @@ function disableCurrency(e) {
     var currencyCode = button.data('code');
 
     var params = {
-        enabled: true
+        enabled: false
     }
 
     $.ajax({
@@ -87,7 +97,12 @@ function disableCurrency(e) {
             'Content-Type': 'application/json',
             'X-CSRF-Token': $('meta[name="csrf-token"]').attr('content'),
         },
+        error: function () {
+            window.location = redirectUrl + '?message=disable_failed&code=' + currencyCode;
+        },
+        success: function () {
+            window.location = redirectUrl + '?message=disabled&code=' + currencyCode;
+        }
     });
-    window.location = redirectUrl + '?message=disabled&code=' + currencyCode;
     return false;
 }

resources/lang/en_US/firefly.php

@@ -1582,7 +1582,8 @@ return [
     'create_currency'                           => 'Create a new currency',
     'store_currency'                            => 'Store new currency',
     'update_currency'                           => 'Update currency',
-    'new_default_currency'                      => ':name is now the default currency.',
+    'new_default_currency'                      => '":name" is now the default currency.',
+    'default_currency_failed'                   => 'Could not make ":name" the default currency. Please check the logs.',
     'cannot_delete_currency'                    => 'Cannot delete :name because it is still in use.',
     'cannot_delete_fallback_currency'           => ':name is the system fallback currency and can\'t be deleted.',
     'cannot_disable_currency_journals'          => 'Cannot disable :name because transactions are still using it.',
@@ -1608,7 +1609,9 @@ return [
     'disable_currency'                          => 'Disable',
     'currencies_default_disabled'               => 'Most of these currencies are disabled by default. To use them, you must enable them first.',
     'currency_is_now_enabled'                   => 'Currency ":name" has been enabled',
+    'could_not_enable_currency'                 => 'Could not enable currency ":name". Please review the logs.',
     'currency_is_now_disabled'                  => 'Currency ":name" has been disabled',
+    'could_not_disable_currency'                => 'Could not disable currency ":name". Perhaps it is still in use?',
 
     // forms:
     'mandatoryFields'                           => 'Mandatory fields',