From d61c6bbf52c93d3ab7bc5e87844dce6696c49e03 Mon Sep 17 00:00:00 2001
From: Philipp Neuhaus <philipp.neuhaus@uni-muenster.de>
Date: Thu, 3 Mar 2022 14:44:30 +0100
Subject: [PATCH] Added an option to redirect links like "/redcap_latest/" as
 well.

---
 README.md           |  7 +++++++
 redcap_redirect.php | 20 +++++++++++++++-----
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index c1da21e..49f2784 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,8 @@ If your apache server receives a request for a url that isn't on disk AND the ur
 The rewrite rule finds that /redcap_v8.1.0/index.php is NOT a valid file but has a 'redcap_vx.y.z' in it so it passes it to the redcap_redirect.php script which queries the database and determines that your redcap version is actually 9.2.5.  So, it redirects the user to:
 `https://redcap.stanford.edu/redcap_v9.2.5/index.php?pid=10601`
 
+- If uncommented, URLs like `https://redcap.stanford.edu/redcap_latest/index.php?pid=10601` will also get redirected to the redcap_redirect.php script
+
 - If a url does NOT contain redcap_vx.y.z the rewrite rule will not take effect and the user will get the default Apache 404 error.
 
 - If a url redcap version is updated, but the file with the new version does not exist, the user will get a nice custom 404 error message:
@@ -33,6 +35,11 @@ The rewrite rule finds that /redcap_v8.1.0/index.php is NOT a valid file but has
     RewriteCond %{REQUEST_URI} "^.*\/redcap_v(\d+\.\d+\.\d+)\/.*$"
     # Redirect to this script to handle the version substitution
     RewriteRule "^(.+)$"   "/redcap_redirect.php"   [PT,L,NS]
+
+    #Optional: Uncomment to also redirect links with "/redcap_latest/" instead of a version...
+    #RewriteCond %{REQUEST_URI} "^.*\/redcap_latest\/.*$"
+    #RewriteRule "^(.+)$"     "/redcap_redirect.php"   [PT,L,NS]
+
 </IfModule>
 ```
 
diff --git a/redcap_redirect.php b/redcap_redirect.php
index c5b1746..1d945d8 100644
--- a/redcap_redirect.php
+++ b/redcap_redirect.php
@@ -24,6 +24,10 @@
         RewriteCond %{REQUEST_URI} "^.*\/redcap_v(\d+\.\d+\.\d+)\/.*$"
         # Redirect to this script to handle the version substitution
         RewriteRule "^(.+)$"     "/redcap_redirect.php"   [PT,L,NS]
+
+        #Optional: Uncomment to also redirect links with "/redcap_latest/" instead of a version...
+        #RewriteCond %{REQUEST_URI} "^.*\/redcap_latest\/.*$"
+        #RewriteRule "^(.+)$"     "/redcap_redirect.php"   [PT,L,NS]
      </IfModule>
 
  * Note: if your redcap server is not installed in the DOCUMENT_ROOT, then you may need to modify the RewriteRule line
@@ -44,16 +48,22 @@
 
 $requestUri = filter_var($_SERVER['REQUEST_URI'], FILTER_SANITIZE_URL);
 
-// Check the redirectURL for a redcap version - https://regex101.com/r/q7oCR5/1
-$re = '/^(.*\/redcap_v)(\d+\.\d+\.\d+)(\/.*?)(\?.*)*$/';
+// Check the redirectURL for a redcap version or the string "redcap_latest" - https://regex101.com/r/q7oCR5/1
+$re = '/^(.*\/redcap_)(v\d+\.\d+\.\d+)(\/.*?)(\?.*)*$/';
 preg_match($re, $requestUri, $uriMatches);
 $uriVersion = empty($uriMatches[2]) ? NULL : $uriMatches[2];
 
-// See if we have a version in the url and it is not current
-if (!empty($uriVersion) && ($uriVersion !== $redcap_version)) {
+if (empty($uriMatches)) {
+  $re = '/^(.*\/redcap_)(latest)(\/.*?)(\?.*)*$/';
+  preg_match($re, $requestUri, $uriMatches);
+  $uriVersion = empty($uriMatches[2]) ? NULL : $uriMatches[2];
+}
+
+// See if we have a version in the url and it is not current (or the string "latest")
+if ((!empty($uriVersion) && ($uriVersion !== $redcap_version)) || $uriVersion == 'latest') {
 
     // Rebuild the new url with the current db version
-    $newUrl = $uriMatches[1] . $redcap_version . $uriMatches[3];
+    $newUrl = $uriMatches[1] . "v" . $redcap_version . $uriMatches[3];
 
     // Build the server path to the url
     $newUrlPath = $_SERVER['DOCUMENT_ROOT'] . $newUrl;