Filters - Add support for also removing HTML elements using XPath selectors (#2632)

changedetectionio/blueprint/tags/templates/edit-tag.html

@@ -89,11 +89,13 @@ xpath://body/div/span[contains(@class, 'example-class')]",
                     {{ render_field(form.subtractive_selectors, rows=5, placeholder="header
 footer
 nav
-.stockticker") }}
+.stockticker
+//*[contains(text(), 'Advertisement')]") }}
                     <span class="pure-form-message-inline">
                         <ul>
-                          <li> Remove HTML element(s) by CSS selector before text conversion. </li>
-                          <li> Add multiple elements or CSS selectors per line to ignore multiple parts of the HTML. </li>
+                          <li> Remove HTML element(s) by CSS and XPath selectors before text conversion. </li>
+                          <li> Don't paste HTML here, use only CSS and XPath selectors </li>
+                          <li> Add multiple elements, CSS or XPath selectors per line to ignore multiple parts of the HTML. </li>
                         </ul>
                       </span>
                 </fieldset>

changedetectionio/forms.py

@@ -469,7 +469,7 @@ class processor_text_json_diff_form(commonSettingsForm):
 
     include_filters = StringListField('CSS/JSONPath/JQ/XPath Filters', [ValidateCSSJSONXPATHInput()], default='')
 
-    subtractive_selectors = StringListField('Remove elements', [ValidateCSSJSONXPATHInput(allow_xpath=False, allow_json=False)])
+    subtractive_selectors = StringListField('Remove elements', [ValidateCSSJSONXPATHInput(allow_json=False)])
 
     extract_text = StringListField('Extract text', [ValidateListRegex()])
 
@@ -576,7 +576,7 @@ class globalSettingsApplicationForm(commonSettingsForm):
     empty_pages_are_a_change =  BooleanField('Treat empty pages as a change?', default=False)
     fetch_backend = RadioField('Fetch Method', default="html_requests", choices=content_fetchers.available_fetchers(), validators=[ValidateContentFetcherIsReady()])
     global_ignore_text = StringListField('Ignore Text', [ValidateListRegex()])
-    global_subtractive_selectors = StringListField('Remove elements', [ValidateCSSJSONXPATHInput(allow_xpath=False, allow_json=False)])
+    global_subtractive_selectors = StringListField('Remove elements', [ValidateCSSJSONXPATHInput(allow_json=False)])
     ignore_whitespace = BooleanField('Ignore whitespace')
     password = SaltyPasswordField()
     pager_size = IntegerField('Pager size',

changedetectionio/html_tools.py

@@ -1,4 +1,5 @@
 from typing import List
+from lxml import etree
 import json
 import re
 
@@ -57,11 +58,26 @@ def subtractive_css_selector(css_selector, html_content):
         item.decompose()
     return str(soup)
 
+def subtractive_xpath_selector(xpath_selector, html_content): 
+    html_tree = etree.HTML(html_content)
+    elements_to_remove = html_tree.xpath(xpath_selector)
+
+    for element in elements_to_remove:
+        element.getparent().remove(element)
+
+    modified_html = etree.tostring(html_tree, method="html").decode("utf-8")
+    return modified_html
 
 def element_removal(selectors: List[str], html_content):
-    """Joins individual filters into one css filter."""
-    selector = ",".join(selectors)
-    return subtractive_css_selector(selector, html_content)
+    """Removes elements that match a list of CSS or xPath selectors."""
+    modified_html = html_content
+    for selector in selectors:
+        if selector.startswith(('xpath:', 'xpath1:', '//')):
+            xpath_selector = selector.removeprefix('xpath:').removeprefix('xpath1:')
+            modified_html = subtractive_xpath_selector(xpath_selector, modified_html)
+        else:
+            modified_html = subtractive_css_selector(selector, modified_html)
+    return modified_html
 
 def elementpath_tostring(obj):
     """

changedetectionio/templates/edit.html

@@ -310,12 +310,13 @@ xpath://body/div/span[contains(@class, 'example-class')]",
                     {{ render_field(form.subtractive_selectors, rows=5, placeholder=has_tag_filters_extra+"header
 footer
 nav
-.stockticker") }}
+.stockticker
+//*[contains(text(), 'Advertisement')]") }}
                     <span class="pure-form-message-inline">
                         <ul>
-                          <li> Remove HTML element(s) by CSS selector before text conversion. </li>
-                          <li> Don't paste HTML here, use only CSS selectors </li>
-                          <li> Add multiple elements or CSS selectors per line to ignore multiple parts of the HTML. </li>
+                          <li> Remove HTML element(s) by CSS and XPath selectors before text conversion. </li>
+                          <li> Don't paste HTML here, use only CSS and XPath selectors </li>
+                          <li> Add multiple elements, CSS or XPath selectors per line to ignore multiple parts of the HTML. </li>
                         </ul>
                       </span>
                 </fieldset>

changedetectionio/templates/settings.html

@@ -155,11 +155,13 @@
                       {{ render_field(form.application.form.global_subtractive_selectors, rows=5, placeholder="header
 footer
 nav
-.stockticker") }}
+.stockticker
+//*[contains(text(), 'Advertisement')]") }}
                       <span class="pure-form-message-inline">
                         <ul>
-                          <li> Remove HTML element(s) by CSS selector before text conversion. </li>
-                          <li> Add multiple elements or CSS selectors per line to ignore multiple parts of the HTML. </li>
+                          <li> Remove HTML element(s) by CSS and XPath selectors before text conversion. </li>
+                          <li> Don't paste HTML here, use only CSS and XPath selectors </li>
+                          <li> Add multiple elements, CSS or XPath selectors per line to ignore multiple parts of the HTML. </li>
                         </ul>
                       </span>
                     </fieldset>

changedetectionio/tests/test_element_removal.py

@@ -87,6 +87,9 @@ def test_element_removal_output():
      Some initial text<br>
      <p>across multiple lines</p>
      <div id="changetext">Some text that changes</div>
+     <div>Some text should be matched by xPath // selector</div>
+     <div>Some text should be matched by xPath selector</div>
+     <div>Some text should be matched by xPath1 selector</div>
      </body>
     <footer>
     <p>Footer</p>
@@ -94,7 +97,16 @@ def test_element_removal_output():
      </html>
     """
     html_blob = element_removal(
-        ["header", "footer", "nav", "#changetext"], html_content=content
+      [
+        "header",
+        "footer",
+        "nav",
+        "#changetext",
+        "//*[contains(text(), 'xPath // selector')]",
+        "xpath://*[contains(text(), 'xPath selector')]",
+        "xpath1://*[contains(text(), 'xPath1 selector')]"
+      ],
+      html_content=content
     )
     text = get_text(html_blob)
     assert (