1 files changed, 39 insertions, 0 deletions
diff --git a/docs/source/_extensions/redirects.py b/docs/source/_extensions/redirects.py
new file mode 100644
index 00000000..6a59b622
--- /dev/null
+++ b/docs/source/_extensions/redirects.py
@@ -0,0 +1,39 @@
+import os
+
+# https://tech.signavio.com/2017/managing-sphinx-redirects
+
+
+template="""<html>
+  <head>
+    <meta http-equiv="refresh" content="1; url=%s" />
+    <script>
+      window.location.href = "%s"
+    </script>
+  </head>
+</html>"""
+
+
+def gather_redirects():
+    output = {}
+
+    output.update({ 'projjson.html' : 'usage/projjson.html' })
+    return output
+
+from shutil import copyfile
+# copy legacy redirects
+def copy_legacy_redirects(app, docname): # Sphinx expects two arguments
+    if app.builder.name == 'html':
+        for key in app.config.redirect_files:
+            src = key
+            tgt = app.config.redirect_files[key]
+            html = template % (tgt, tgt)
+            with open(os.path.join(app.outdir, src), 'wb') as f:
+                f.write(html.encode('utf-8'))
+                f.close()
+
+
+
+def setup(app):
+    app.add_config_value('redirect_files', {}, 'html')
+    app.connect('build-finished', copy_legacy_redirects)
+    return { 'parallel_read_safe': False, 'parallel_write_safe': True }