Added new IIIF_DELIMITTER configuration parameter to enable page or s…

…tack slice selection. Now disabled by default unless IIIF_DELIMITTER is set. Resolves: #261

ChangeLog

@@ -1,3 +1,8 @@
+19/10/2023:
+	- Added new IIIF_DELIMITTER configuration parameter to enable page or stack slice selection. Now disabled
+	  by default unless IIIF_DELIMITTER is set. Resolves: https://github.com/ruven/iipsrv/issues/261
+
+
 03/10/2023:
 	- Cleanup of autoconf C++ checks and added conditional building of FCGI
 	- Fixes for compilation errors on Mac OS X / clang

README

@@ -246,6 +246,9 @@ recovery, 2 for 'resilient' mode with maximum recovery from codestream errors. S
 IIIF_VERSION: Set the major IIIF Image API version. Values should be a single digit. For example: 2 for versions 2 or 2.1 etc.
 3 for IIIF version 3.x. If not set, defaults to version IIIF 3.x
 
+IIIF_DELIMITTER: Set delimitter to enable page or slice selection for a multi-page or image stack for IIIF requests.
+Delimitter can be a single character or an arbitrary string. Disabled by default.
+
 DECODER_MODULES: Comma separated list of external modules for decoding 
 other image formats. This is only necessary if you have activated 
 --enable-modules for ./configure and written your own image format 

src/Environment.h

@@ -49,6 +49,7 @@
 #define EMBED_ICC true
 #define KAKADU_READMODE 0
 #define IIIF_VERSION 3
+#define IIIF_DELIMITTER ""
 
 
 #include <string>
@@ -343,6 +344,12 @@ class Environment {
   }
 
 
+  static std::string getIIIFDelimitter(){
+    const char* envpara = getenv( "IIIF_DELIMITTER" );
+    if( envpara ) return std::string( envpara );
+    else return IIIF_DELIMITTER;
+  }
+
 };
 
 

src/IIIF.cc

@@ -47,6 +47,11 @@
 
 using namespace std;
 
+
+// Need to initialize static member
+string IIIF::delimitter = "";
+
+
 // The request is in the form {identifier}/{region}/{size}/{rotation}/{quality}{.format}
 //     eg. filename.tif/full/full/0/native.jpg
 // or in the form {identifier}/info.json
@@ -121,11 +126,12 @@ void IIIF::run( Session* session, const string& src )
     return;
   }
 
+  // Re-usable string position variable
+  size_t pos;
+
   // Extract any meta-identifier in the file name that may refer to a page within an image stack or multi-page image
   // These consist of a semi-colon and a page or stack index of the form <image>;<index> For example: image.tif;3
-  const char delimitter = ',';
-  if( filename.find_last_of( delimitter ) != string::npos ){
-    size_t pos = filename.find_last_of( delimitter );
+  if( IIIF::delimitter.size() && ( (pos=filename.rfind(IIIF::delimitter)) != string::npos ) ){
     int page = atoi( filename.substr(pos+1).c_str() );
     session->view->xangle = page;
     filename = filename.substr(0,pos);
@@ -158,7 +164,7 @@ void IIIF::run( Session* session, const string& src )
 
   // Check whether the client has requested a specific IIIF version within the HTTP Accept header
   //  - first look for the protocol prefix
-  size_t pos = session->headers["HTTP_ACCEPT"].find( IIIF_PROTOCOL );
+  pos = session->headers["HTTP_ACCEPT"].find( IIIF_PROTOCOL );
   if( pos != string::npos ){
     // The Accept header should contain a versioned context string of the form http://iiif.io/api/image/3/context.json
     string profile = session->headers["HTTP_ACCEPT"].substr( pos, string(IIIF_PROTOCOL).size()+15 );

src/Main.cc

@@ -333,6 +333,10 @@ int main( int argc, char *argv[] )
   unsigned int iiif_version = Environment::getIIIFVersion();
 
 
+  // Set our IIIF multi-page delimitter
+  IIIF::delimitter = Environment::getIIIFDelimitter();
+
+
   // Create our image processing engine
   Transform processor;
 
@@ -367,6 +371,9 @@ int main( int argc, char *argv[] )
     logfile << "Setting HTTP Cache-Control header to '" << cache_control << "'" << endl;
     logfile << "Setting 3D file sequence name pattern to '" << filename_pattern << "'" << endl;
     logfile << "Setting default IIIF Image API version to " << iiif_version << endl;
+    if( IIIF::delimitter.size() ){
+      logfile << "Setting default IIIF multi-page delimitter to '" << IIIF::delimitter << "'" << endl;
+    }
     if( !cors.empty() ) logfile << "Setting Cross Origin Resource Sharing to '" << cors << "'" << endl;
     if( !base_url.empty() ) logfile << "Setting base URL to '" << base_url << "'" << endl;
     if( max_layers != 0 ){

src/Task.h

@@ -18,7 +18,6 @@
     Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 */
 
-
 #ifndef _TASK_H
 #define _TASK_H
 
@@ -355,6 +354,7 @@ class DeepZoom : public Task {
 /// IIIF Command
 class IIIF : public Task {
  public:
+  static std::string delimitter;
   void run( Session* session, const std::string& argument );
 };