[Modules] [PATCH] Add environment variables to the params set for mod_transform

[Vincent Bray]

Hi,

Attached is a patch which sends r->subprocess_env to the params
argument of xsltApplyStylesheet() for the 0.6.0 release of
mod_transform, as requested by a user on #apache. It's my first
attempt at doing anything useful with C but I've got thick skin so if
it's crap, say so :-)

-- 
noodl
-------------- next part --------------
Index: include/mod_transform_private.h
===================================================================
--- include/mod_transform_private.h	(revision 92)
+++ include/mod_transform_private.h	(working copy)
@@ -115,6 +115,14 @@
 }
 transform_xmlio_input_ctx;
 
+typedef struct
+{
+    int counter;
+    request_rec *r;
+    const char **params;
+}
+params_ctx;
+
 apr_status_t transform_apachefs_filter(ap_filter_t * f,
                                        apr_bucket_brigade * bb);
 
Index: src/mod_transform.c
===================================================================
--- src/mod_transform.c	(revision 92)
+++ src/mod_transform.c	(working copy)
@@ -61,6 +61,52 @@
     return NULL;
 }
 
+/* apr_table_do callback for populating the xslt params array */
+static int populate_params(void *rec, const char *key, const char *value)
+{
+    params_ctx *ctx = rec;
+    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, ctx->r, 
+                  "mod_transform: populating array with: (%d) %s - %s",
+                  ctx->counter, key, value);
+    ctx->params[ctx->counter++] = key;
+    ctx->params[ctx->counter++] = value;
+    return 1;
+}
+
+/* Convert subprocess_env to the format libxslt expects for params */
+static char *env_to_params(request_rec *r)
+{
+    int params_cnt, env_cnt;
+    const char **params;
+    params_ctx *ctx;
+    
+    /* Get the number of entries in the env table. */
+    env_cnt = apr_table_elts(r->subprocess_env)->nelts;
+    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
+                  "mod_transform: Env var count: %d", env_cnt);
+    
+    /** 
+     * Create the params array large enough to hold a flattened, null terminated
+     * subprocess_env. The format is:
+     * const char *feh[] = {"key", "val", "key", "val", NULL};
+     */
+    params_cnt = env_cnt * 2 + 1;
+    params = apr_palloc(r->pool, sizeof(char *) * params_cnt);
+    
+    /* Use this simple struct to keep state in the callback */
+    ctx = apr_palloc(r->pool, sizeof(params_ctx));
+    ctx->r = r;
+    ctx->counter = 0;
+    ctx->params = params;
+    
+    /* Populate params */
+    apr_table_do(populate_params, ctx, r->subprocess_env);
+    /* Terminate the array */
+    ctx->params[params_cnt - 1] = NULL;
+    
+    return ctx->params;
+}
+
 static apr_status_t transform_run(ap_filter_t * f, xmlDocPtr doc)
 {
     size_t length;
@@ -77,6 +123,7 @@
                                           &transform_module);
     svr_cfg *sconf = ap_get_module_config(f->r->server->module_config,
                                           &transform_module);
+    const char **params;
 
     if (!doc) {
         return pass_failure(f, "XSLT: Couldn't parse XML Document", notes);
@@ -128,7 +175,9 @@
         return pass_failure(f, "XSLT: Loading of the XSLT File has failed", notes);
     }
 
-    result = xsltApplyStylesheet(transform, doc, 0);
+    params = env_to_params(f->r);
+    
+    result = xsltApplyStylesheet(transform, doc, params);
     if (!result) {
         if (!stylesheet_is_cached) {
             xsltFreeStylesheet(transform);