Extra validation

changedetectionio/__init__.py

@@ -814,11 +814,12 @@ def changedetection_app(config=None, datastore_o=None):
     @login_required
     def diff_history_page(uuid):
 
+        from changedetectionio import forms
+
         # More for testing, possible to return the first/only
         if uuid == 'first':
             uuid = list(datastore.data['watching'].keys()).pop()
 
-
         extra_stylesheets = [url_for('static_content', group='styles', filename='diff.css')]
         try:
             watch = datastore.data['watching'][uuid]
@@ -827,7 +828,12 @@ def changedetection_app(config=None, datastore_o=None):
             return redirect(url_for('index'))
 
         # For submission of requesting an extract
+        extract_form = forms.extractDataForm(request.form)
         if request.method == 'POST':
+            if not extract_form.validate():
+                flash("An error occurred, please see below.", "error")
+
+            else:
                 extract_regex = request.form.get('extract_regex').strip()
                 output = watch.extract_regex_from_all_history(extract_regex)
                 if output:
@@ -884,9 +890,6 @@ def changedetection_app(config=None, datastore_o=None):
         is_html_webdriver = True if watch.get('fetch_backend') == 'html_webdriver' or (
                     watch.get('fetch_backend', None) is None and system_uses_webdriver) else False
 
-        from changedetectionio import forms
-        extract_form = forms.extractDataForm(request.form)
-
         output = render_template("diff.html",
                                  current_diff_url=watch['url'],
                                  current_previous_version=str(previous_version),

changedetectionio/forms.py

@@ -451,6 +451,5 @@ class globalSettingsForm(Form):
 
 
 class extractDataForm(Form):
-    extract_regex = StringField('RegEx to extract')
+    extract_regex = StringField('RegEx to extract', validators=[validators.Length(min=1, message="Needs a RegEx")])
     extract_submit_button = SubmitField('Extract as CSV', render_kw={"class": "pure-button pure-button-primary"})
-