src/hg/hgApi/hgApi.c 1.1

Index: src/hg/hgApi/hgApi.c
===================================================================
RCS file: src/hg/hgApi/hgApi.c
diff -N src/hg/hgApi/hgApi.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/hg/hgApi/hgApi.c	21 May 2010 20:26:48 -0000	1.1
@@ -0,0 +1,97 @@
+/* hgApi - provide a JSON based API to the browser. */
+
+#include "common.h"
+#include "hdb.h"
+#include "cheapcgi.h"
+#include "hPrint.h"
+#include "dystring.h"
+
+static char const rcsid[] = "$Id$";
+
+static void fail(char *msg)
+{
+puts("Status: 400\n\n");
+puts(msg);
+exit(-1);
+}
+
+void makeIndent(char *buf, int bufLen, int indent)
+{
+indent = min(indent, bufLen - 2);
+memset(buf, '\t', indent);
+buf[indent] = 0;
+}
+
+static void trackJson(struct dyString *json, struct trackDb *tdb, int *count, int indent)
+{
+char tabs[100];
+makeIndent(tabs, sizeof(tabs), indent);
+if((*count)++)
+    dyStringPrintf(json, ",\n");
+dyStringPrintf(json, "%s\"%s\": {\n", tabs, tdb->track);
+makeIndent(tabs, sizeof(tabs), indent + 1);
+dyStringPrintf(json, "%s\"shortLabel\": \"%s\",\n%s\"longLabel\": \"%s\",\n%s\"group\": \"%s\"",
+               tabs, javaScriptLiteralEncode(tdb->shortLabel), tabs, javaScriptLiteralEncode(tdb->longLabel),
+               tabs, javaScriptLiteralEncode(tdb->grp));
+if(tdbIsComposite(tdb) && tdb->subtracks != NULL)
+    {
+    struct trackDb *ptr;
+    dyStringPrintf(json, ",\n%s\"subtracks\": {\n", tabs);
+    int count = 0;
+    for (ptr = tdb->subtracks; ptr != NULL; ptr = ptr->next)
+        {
+        trackJson(json, ptr, &count, indent + 2);
+        }
+    dyStringPrintf(json, "\n%s}", tabs);
+    }
+makeIndent(tabs, sizeof(tabs), indent);
+dyStringPrintf(json, "\n%s}", tabs);
+}
+
+int main(int argc, char *argv[])
+{
+struct dyString *output = newDyString(1000);
+char *database = cgiOptionalString("db");
+char *cmd = cgiOptionalString("cmd");
+char *jsonp = cgiOptionalString("jsonp");
+if(database)
+    database = sqlEscapeString(database);
+
+if(!cmd)
+    fail("Missing 'cmd' parameter");
+
+if(!strcmp(cmd, "trackList"))
+    {
+    if(database)
+        {
+        struct trackDb *tdb, *tdbList = NULL;
+        tdbList = hTrackDb(database, NULL);
+        dyStringPrintf(output, "{\n");
+        int count = 0;
+        for (tdb = tdbList; tdb != NULL; tdb = tdb->next)
+            {
+            trackJson(output, tdb, &count, 1);
+            count++;
+            }
+        dyStringAppend(output, "\n}\n");
+        }
+    else
+        {
+        fail("Missing 'db' parameter");
+        }
+    }
+else
+    fail("Unsupported 'cmd' parameter");
+
+// It's debatable whether the type should be text/plain, text/javascript or application/javascript; I think
+// any of the types containing "javascript" don't work with IE6, so I'm using text/plain
+
+puts("Content-Type:text/plain");
+puts("\n");
+if(jsonp)
+    printf("%s(%s)", jsonp, dyStringContents(output));
+else 
+    puts(dyStringContents(output));
+
+return 0;
+}