refactor: mathjax: Add a constant for the URL of mathjax

1 files changed, 6 insertions, 5 deletions

diff --git a/sphinx/ext/mathjax.py b/sphinx/ext/mathjax.py
index e4318f35d..141f61735 100644
--- a/sphinx/ext/mathjax.py
+++ b/sphinx/ext/mathjax.py
@@ -25,6 +25,11 @@ from sphinx.locale import _
 from sphinx.util.math import get_node_equation_number
 from sphinx.writers.html import HTMLTranslator
 
+# more information for mathjax secure url is here:
+# https://docs.mathjax.org/en/latest/start.html#secure-access-to-the-cdn
+MATHJAX_URL = ('https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.7/latest.js?'
+               'config=TeX-AMS-MML_HTMLorMML')
+
 
 def html_visit_math(self: HTMLTranslator, node: nodes.math) -> None:
     self.body.append(self.starttag(node, 'span', '', CLASS='math notranslate nohighlight'))
@@ -92,11 +97,7 @@ def setup(app: Sphinx) -> Dict[str, Any]:
                                (html_visit_math, None),
                                (html_visit_displaymath, None))
 
-    # more information for mathjax secure url is here:
-    # https://docs.mathjax.org/en/latest/start.html#secure-access-to-the-cdn
-    app.add_config_value('mathjax_path',
-                         'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.7/latest.js?'
-                         'config=TeX-AMS-MML_HTMLorMML', 'html')
+    app.add_config_value('mathjax_path', MATHJAX_URL, 'html')
     app.add_config_value('mathjax_options', {}, 'html')
     app.add_config_value('mathjax_inline', [r'\(', r'\)'], 'html')
     app.add_config_value('mathjax_display', [r'\[', r'\]'], 'html')