From 41887e90168fec96c109225aa011359a0218fea8 Mon Sep 17 00:00:00 2001
From: Sam Hatchett <sam.hatchett@xylem.com>
Date: Wed, 27 Jul 2022 16:37:49 -0400
Subject: [PATCH] adds client callback API function

---
 include/epanet2_2.h | 12 ++++++++++++
 src/epanet.c        | 13 +++++++++++++
 src/project.c       |  2 ++
 src/report.c        |  6 ++++++
 src/types.h         |  5 ++++-
 5 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/include/epanet2_2.h b/include/epanet2_2.h
index 18ef127..ddd1db7 100644
--- a/include/epanet2_2.h
+++ b/include/epanet2_2.h
@@ -517,6 +517,18 @@ typedef struct Project *EN_Project;
 
   ********************************************************************/
 
+  /**
+  @brief Set a user-supplied callback function for reporting
+  @param ph an EPANET project handle.
+  @param callback a function pointer with declared signature, which gets called by EPANET for reporting.
+  @return an error code.
+  @details The report callback function must have the signature specified - void(void* userData, EN_Project, char*) -
+           use the userData parameter to pass any client context necessary (a context pointer or wrapper object perhaps).
+           Leave un-set or set the report callback to NULL to revert to EPANET's default behavior.
+  **/
+  int DLLEXPORT EN_setReportCallback(EN_Project ph, void (*callback)(void *userData, void *EN_projectHandle, char*));
+  int DLLEXPORT EN_setReportCallbackUserData(EN_Project ph, void *userData);
+
   /**
   @brief Writes a line of text to a project's report file.
   @param ph an EPANET project handle.
diff --git a/src/epanet.c b/src/epanet.c
index 9a3c194..6c2ba3d 100644
--- a/src/epanet.c
+++ b/src/epanet.c
@@ -841,6 +841,19 @@ int DLLEXPORT EN_closeQ(EN_Project p)
 
  ********************************************************************/
 
+
+ int  DLLEXPORT EN_setReportCallback(EN_Project p, void (*callback)(void*,void*,char*))
+ {
+   p->report.reportCallback = callback;
+   return 0;
+ }
+
+ int DLLEXPORT EN_setReportCallbackUserData(EN_Project p, void *userData)
+ {
+   p->report.reportCallbackUserData = userData;
+   return 0;
+ }
+
 int DLLEXPORT EN_writeline(EN_Project p, char *line)
 /*----------------------------------------------------------------
 **  Input:   line = line of text
diff --git a/src/project.c b/src/project.c
index b470ec3..40f5639 100644
--- a/src/project.c
+++ b/src/project.c
@@ -281,6 +281,8 @@ void initpointers(Project *pr)
     pr->hydraul.smatrix.NZSUB = NULL;
     pr->hydraul.smatrix.LNZ = NULL;
 
+    pr->report.reportCallback = NULL;
+
     initrules(pr);
 }
 
diff --git a/src/report.c b/src/report.c
index 8fc6d16..2922332 100644
--- a/src/report.c
+++ b/src/report.c
@@ -885,6 +885,12 @@ void writeline(Project *pr, char *s)
 **--------------------------------------------------------------
 */
 {
+    if (pr->report.reportCallback != NULL)
+    {
+        pr->report.reportCallback(pr->report.reportCallbackUserData, pr, s);
+        return;
+    }
+
     Report *rpt = &pr->report;
 
     if (rpt->RptFile == NULL) return;
diff --git a/src/types.h b/src/types.h
index b0e91b5..27d2fd7 100755
--- a/src/types.h
+++ b/src/types.h
@@ -629,7 +629,10 @@ typedef struct {
     Rpt2Fname[MAXFNAME+1], // Secondary report file name
     DateStamp[26];         // Current date & time
 
-  SField   Field[MAXVAR];  // Output reporting fields
+    SField   Field[MAXVAR];  // Output reporting fields
+
+    void (*reportCallback)(void*,void*,char*); // user-supplied reporting callback
+    void *reportCallbackUserData;  // user-supplied reporting context
 
 } Report;