From 28dfae3e7c5d7291a4036358050c9c886ee43316 Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Fri, 16 Dec 2022 16:00:13 +0100
Subject: [PATCH] expose templating API for in-memory data

---
 contrib/gana                       |  2 +-
 src/include/taler_templating_lib.h | 17 +++++++++++++++++
 src/templating/templating_api.c    | 25 +++++++++++++++++++++++++
 3 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/contrib/gana b/contrib/gana
index 149aa0a08..20f8eb7a7 160000
--- a/contrib/gana
+++ b/contrib/gana
@@ -1 +1 @@
-Subproject commit 149aa0a08d787419e02277ef231d93c6a0154a47
+Subproject commit 20f8eb7a72e2160409f0f78264ec5198e9caa193
diff --git a/src/include/taler_templating_lib.h b/src/include/taler_templating_lib.h
index e4f3f1f1c..53946b9c0 100644
--- a/src/include/taler_templating_lib.h
+++ b/src/include/taler_templating_lib.h
@@ -24,6 +24,23 @@
 #include <microhttpd.h>
 
 
+/**
+ * Fill in Mustach template @a tmpl using the data from @a root
+ * and return the result in @a result.
+ *
+ * @param tmpl 0-terminated string with Mustach template
+ * @param root JSON data to fill into the template
+ * @param[out] result where to write the result
+ * @param[out] result_size where to write the length of the result
+ * @return 0 on success, otherwise Mustach-specific error code
+ */
+int
+TALER_TEMPLATING_fill (const char *tmpl,
+                       const json_t *root,
+                       void **result,
+                       size_t *result_size);
+
+
 /**
  * Load a @a template and substitute using @a root, returning the result in a
  * @a reply encoded suitable for the @a connection with the given @a
diff --git a/src/templating/templating_api.c b/src/templating/templating_api.c
index 47ada208e..324e199eb 100644
--- a/src/templating/templating_api.c
+++ b/src/templating/templating_api.c
@@ -171,6 +171,31 @@ make_static_url (struct MHD_Connection *con,
 }
 
 
+int
+TALER_TEMPLATING_fill (const char *tmpl,
+                       const json_t *root,
+                       void **result,
+                       size_t *result_size)
+{
+  int eno;
+
+  if (0 !=
+      (eno = mustach_jansson (tmpl,
+                              (json_t *) root,
+                              (char **) result,
+                              result_size)))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "mustach failed on template with error %d\n",
+                eno);
+    *result = NULL;
+    *result_size = 0;
+    return eno;
+  }
+  return eno;
+}
+
+
 enum GNUNET_GenericReturnValue
 TALER_TEMPLATING_build (struct MHD_Connection *connection,
                         unsigned int *http_status,