Perform validation of ext URL during form editing

cmsplugin_cascade/admin.py

@@ -1,4 +1,5 @@
 from urllib.parse import urlparse
+import requests
 
 from django.conf.urls import url
 from django.contrib import admin
@@ -42,6 +43,7 @@ def get_urls(self):
             url(r'^published_pages/$', self.get_published_pagelist, name='get_published_pagelist'),
             url(r'^fetch_fonticons/(?P<iconfont_id>[0-9]+)$', self.fetch_fonticons),
             url(r'^fetch_fonticons/$', self.fetch_fonticons, name='fetch_fonticons'),
+            url(r'^validate_exturl/$', self.validate_exturl, name='validate_exturl'),
         ]
         urls.extend(super().get_urls())
         return urls
@@ -111,6 +113,19 @@ def fetch_fonticons(self, request, iconfont_id=None):
             data['families'] = icon_font.get_icon_families()
             return JsonResponse(data)
 
+    def validate_exturl(self, request):
+        """
+        Perform a GET request onto the given external URL and return its status.
+        """
+        exturl = request.GET.get('exturl')
+        request_headers = {'User-Agent': 'Django-CMS-Cascade'}
+        try:
+            response = requests.get(exturl, allow_redirects=True, headers=request_headers)
+        except Exception:
+            return JsonResponse({'status_code': 500})
+        else:
+            return JsonResponse({'status_code': response.status_code})
+
     def changeform_view(self, request, object_id=None, form_url='', extra_context=None):
         extra_context = dict(extra_context or {}, icon_fonts=IconFont.objects.all())
         return super().changeform_view(

cmsplugin_cascade/link/forms.py

@@ -1,4 +1,3 @@
-import requests
 from django.core.exceptions import ObjectDoesNotExist, ValidationError
 from django.contrib.admin.sites import site as admin_site
 from django.db.models.fields.related import ManyToOneRel
@@ -11,7 +10,8 @@
 
 from cms.utils import get_current_site
 from cms.models import Page
-from entangled.forms import EntangledModelFormMixin, get_related_object
+from entangled.forms import EntangledModelFormMixin
+from entangled.utils import get_related_object
 from filer.models.filemodels import File as FilerFileModel
 from filer.fields.file import AdminFileWidget, FilerFileField
 
@@ -199,23 +199,8 @@ def _post_clean(self):
                 self.add_error('download_file', error)
         elif link_type == 'exturl':
             ext_url = self.cleaned_data['glossary'].get('ext_url', False)
-            if ext_url:
-                try:
-                    request_headers = {'User-Agent': 'Django-CMS-Cascade'}
-                    response = requests.head(ext_url, allow_redirects=True, headers=request_headers)
-                    if response.status_code != 200:
-                        error = ValidationError(
-                            _("No external page found on {url}.").format(url=ext_url),
-                            code='invalid',
-                        )
-                except Exception as exc:
-                    error = ValidationError(
-                        _("Failed to connect to {url}.").format(url=ext_url),
-                        code='invalid',
-                    )
-            elif ext_url in empty_fields:
+            if ext_url in empty_fields:
                 error = ValidationError(_("No valid URL provided."), code='required')
-            if error:
                 self.add_error('ext_url', error)
         elif link_type == 'email':
             if self.cleaned_data['glossary'].get('mail_to', False) in empty_fields:

cmsplugin_cascade/link/plugin_base.py

@@ -16,6 +16,7 @@ class LinkPluginBase(CascadePluginBase):
     html_tag_attributes = {'title': 'title', 'target': 'target'}
 
     class Media:
+        css = {'all': ['cascade/css/admin/linkplugin.css']}
         js = ['admin/js/jquery.init.js', 'cascade/js/admin/linkplugin.js']
 
     @classmethod

cmsplugin_cascade/static/cascade/css/admin/linkplugin.css

@@ -0,0 +1,13 @@
+#id_ext_url {
+  background-position-x: calc(100% - 8px);
+  background-position-y: 50%;
+  background-clip: padding-box;
+  background-size: 24px;
+  background-repeat: no-repeat;
+}
+#id_ext_url.valid {
+  background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" fill="green" width="16" height="16"><path fill-rule="evenodd" d="M10.97 4.97a.75.75 0 0 1 1.071 1.05l-3.992 4.99a.75.75 0 0 1-1.08.02L4.324 8.384a.75.75 0 1 1 1.06-1.06l2.094 2.093 3.473-4.425a.236.236 0 0 1 .02-.022z"/></svg>') !important;
+}
+#id_ext_url.invalid {
+  background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" fill="darkorange" width="16" height="16"><path d="M7.938 2.016A.13.13 0 0 1 8.002 2a.13.13 0 0 1 .063.016.146.146 0 0 1 .054.057l6.857 11.667c.036.06.035.124.002.183a.163.163 0 0 1-.054.06.116.116 0 0 1-.066.017H1.146a.115.115 0 0 1-.066-.017.163.163 0 0 1-.054-.06.176.176 0 0 1 .002-.183L7.884 2.073a.147.147 0 0 1 .054-.057zm1.044-.45a1.13 1.13 0 0 0-1.96 0L.165 13.233c-.457.778.091 1.767.98 1.767h13.713c.889 0 1.438-.99.98-1.767L8.982 1.566z"/><path d="M7.002 12a1 1 0 1 1 2 0 1 1 0 0 1-2 0zM7.1 5.995a.905.905 0 1 1 1.8 0l-.35 3.507a.552.552 0 0 1-1.1 0L7.1 5.995z"/></svg>');
+}

cmsplugin_cascade/static/cascade/js/admin/linkplugin.js

@@ -1,6 +1,7 @@
 django.jQuery(function($) {
 	'use strict';
 	var $link_type = $("#id_link_type"), $cmspage_select = $("#id_cms_page");
+	var $link_ext_url = $('#id_ext_url');
 	var $link_target = $(".form-row.field-link_target");
 	var $link_title = $(".form-row.field-link_title");
 
@@ -34,6 +35,9 @@ django.jQuery(function($) {
 			$cmspage_select.change(function(evt) {
 				self.toggleCMSPage(evt.target.value);
 			});
+			$link_ext_url.on('blur', function(evt) {
+				self.validateExtUrl(evt.target.value);
+			});
 			this.refreshChangeForm();
 		},
 		initializeLinkTypes: function() {
@@ -73,8 +77,20 @@ django.jQuery(function($) {
 				$selSection.val(null);
 			});
 		},
+		validateExtUrl: function(exturl) {
+			$.get(django.cascade.validate_exturl_url, {
+				exturl: exturl,
+			}, function(response) {
+				if (response.status_code === 200) {
+					$link_ext_url.addClass('valid').removeClass('invalid');
+				} else {
+					$link_ext_url.addClass('invalid').removeClass('valid');
+				}
+			});
+		},
 		refreshChangeForm: function() {
 			this.toggleLinkTypes($link_type.val());
+			this.validateExtUrl($link_ext_url.val());
 			this.$super && this.$super();
 		}
 	});

cmsplugin_cascade/templates/cascade/admin/change_form.html

@@ -31,6 +31,7 @@ <h2>{% trans "There are no further settings for this plugin" %}</h2>
 		'{{ icof.id }}': '{{ icof.get_stylesheet_url }}'{% if not forloop.last %},{% endif %}{% endfor %}
 	};
 	django.cascade.fetch_fonticons_url = "{% url 'admin:fetch_fonticons' %}";
+	django.cascade.validate_exturl_url = "{% url 'admin:validate_exturl' %}";
 	{% endif %}
 	</script>
 {% endblock %}