Made changes to make yelp read the cached HTML files. Fixes #85258 new

2002-08-07  Narayana Pattipati <narayana.pattipati@wipro.com>

	* src/yelp-reader.c (yelp_reader_start): Made changes to make yelp
          read the cached HTML files. Fixes #85258
	* src/yelp-pregenerate.c: new file. Creates yelp-pregenerate utility
          which pre-generates HTML files from XML files.
	* src/yelp-pregenerate.h: new file
	* src/yelp-reader.h: Added prototype for look_for_html_help_file

8 files changed, 748 insertions, 42 deletions

diff --git a/ChangeLog b/ChangeLog
index f7363b9d..d01a8852 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2002-08-07  Narayana Pattipati <narayana.pattipati@wipro.com>
+
+	* src/yelp-reader.c (yelp_reader_start): Made changes to make yelp
+          read the cached HTML files. Fixes #85258
+	* src/yelp-pregenerate.c: new file. Creates yelp-pregenerate utility
+          which pre-generates HTML files from XML files.
+	* src/yelp-pregenerate.h: new file
+	* src/yelp-reader.h: Added prototype for look_for_html_help_file
+
 2002-08-05  Sander Vesik <sander.vesik@sun.com>
 	* stylesheets/yelp-customization.xsl:
 	- apply bold formating to guibuttons
diff --git a/src/.cvsignore b/src/.cvsignore
index 7ed37c19..508f2c41 100644
--- a/src/.cvsignore
+++ b/src/.cvsignore
@@ -16,4 +16,5 @@ yelp-marshal.c
 yelp-marshal.h
 yelp
 yelp-db2html
+yelp-pregenerate
 core*
diff --git a/src/Makefile.am b/src/Makefile.am
index 3ad5e772..d9ca4014 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -10,7 +10,8 @@ INCLUDES =								\
 	-DGNOMELOCALEDIR=\""$(yelplocaledir)"\"				\
 	-DLIBGNOME_MAN2HTML=\"$(LIBGNOME_MAN2HTML)\"			\
 	-DLIBGNOME_INFO2HTML=\"$(LIBGNOME_INFO2HTML)\"			\
-	-DSERVERDIR=\"$(libexecdir)\"
+	-DSERVERDIR=\"$(libexecdir)\"					\
+	-DBINDIR=\""$(bindir)"\"
 
 
 if HTML_WIDGET_GTKHTML1
@@ -20,7 +21,7 @@ html_widget_impl=yelp-html-gtkhtml2.c
 endif
 
 libexec_PROGRAMS = yelp-db2html
-bin_PROGRAMS = yelp
+bin_PROGRAMS = yelp yelp-pregenerate
 
 noinst_PROGRAMS = test-uri test-reader
 
@@ -66,9 +67,15 @@ yelp-marshal-main.c: yelp-marshal.c
 yelp_db2html_SOURCES =							\
 	yelp-db2html.c
 
+yelp_pregenerate_SOURCES =						\
+	yelp-pregenerate.c      yelp-pregenerate.h
+
 yelp_db2html_LDADD =							\
 	@YELP_LIBS@
 
+yelp_pregenerate_LDADD =						\
+	@YELP_LIBS@
+
 yelp_SOURCES =								\
 	$(gnome_yelp_idl_sources)					\
 	yelp-base.c		yelp-base.h				\
diff --git a/src/yelp-db2html.c b/src/yelp-db2html.c
index b90fc77c..3d97713f 100644
--- a/src/yelp-db2html.c
+++ b/src/yelp-db2html.c
@@ -1,3 +1,4 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
 /*
  * gnome-db2html3 - by John Fleck - based on Daniel Veillard's
  * xsltproc: user program for the XSL Transformation engine
diff --git a/src/yelp-pregenerate.c b/src/yelp-pregenerate.c
new file mode 100644
index 00000000..70608940
--- /dev/null
+++ b/src/yelp-pregenerate.c
@@ -0,0 +1,510 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+/*
+ * Copyright (C) 2002 Sun Microsyatems Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc.,  59 Temple Place - Suite 330, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <config.h>
+#include <glib.h>
+#include <string.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include <libgnome/gnome-i18n.h>
+#include <libxml/xmlversion.h>
+#include <libxml/xmlmemory.h>
+#include <libxml/debugXML.h>
+#include <libxml/HTMLtree.h>
+#include <libxml/DOCBparser.h>
+#include <libxml/catalog.h>
+#include "yelp-pregenerate.h"
+
+static gboolean   parse_books         (GNode        *tree,
+                                       xmlDoc       *doc);
+static gboolean   parse_section       (GNode        *parent,
+                                       xmlNode      *xml_node);
+static void       parse_doc_source    (GNode        *parent,
+                                       xmlNode      *xml_node,
+                                       gchar        *docid);
+static gchar *    strip_scheme        (gchar        *original_uri,
+                                       gchar        **scheme);
+
+static gboolean   tree_empty	      (xmlNode 	    *cl_node);
+static gboolean   trim_empty_branches (xmlNode      *cl_node);
+Section *	  section_new 	      (SectionType   type,
+				       const gchar  *name);
+
+static gboolean   yelp_pregenerate_write_to_html (gchar 	*xml_file,
+					   	  gchar         *html_data);
+
+static GHashTable *seriesid_hash = NULL;
+static GHashTable *docid_hash    = NULL;
+static GList 	  *xml_list      = NULL;
+
+#define YELP_DB2HTML BINDIR"/yelp-db2html"
+#define BUFFER_SIZE 16384
+
+
+gint 
+main (gint argc, gchar **argv) 
+{
+	/* This utility pre-generates HTML files from a given list of XML
+	 * files. 
+	 */
+
+	gchar  *xml_url;
+	gchar  *xml_file;
+	gchar  *command_line = NULL;
+ 	gchar  *html_data = NULL;	
+	GError *error = NULL;
+	gint    exit_status;
+	GList  *index;
+	GNode  *tree;
+	FILE   *fp = NULL;
+	gchar   buffer[256];
+	int    c = 0;
+	
+	if (argc < 2) {
+		g_print ("Pre-generates HTML files from XML files. This uses yelp-db2html executable\nfor XML to HTML conversion.\n\nUsage: yelp-pregenerate [OPTIONS] \n\n"
+			 "-a :                 Pregenerate HTMLs for all XML files installed in \n                     the system\n"
+			 "-f <XML-LIST-FILE> : Pregenerate HTMLs for all the XML files specified in\n                     file XML-LIST-FILE. Enter full path of XML-LIST-FILE\n"
+			 "<XML_FILE(S)>....  : Enter one or more XML files to be converted to \n                     HTML files on the command line\n\n");
+
+		exit (1);
+	}
+
+	c = getopt (argc, argv, "af:");
+
+	switch (c) {
+	case 'a':
+                g_print ("Pre-generating HTMLs for all XML files installed in the system.\n");
+                tree = g_new0 (GNode, 1);
+                
+                yelp_pregenerate_xml_list_init (tree);	
+                
+                g_node_destroy (tree);
+                break;
+	case 'f':
+                g_print ("Pre-generating HTMLs for the list of XML files specified in %s\n", argv[optind - 1]);
+
+                fp = fopen (argv[optind - 1], "r");
+
+                if (fp == NULL) {
+                        g_print ("Error in opening the file %s\n", 
+                                 argv[optind - 1]);
+                        exit (1);
+                }
+
+                while (fgets (buffer, 256, fp) != NULL) {
+                        xml_file = g_strchomp (buffer);	
+                        xml_list = g_list_append (xml_list, g_strdup(xml_file));
+                }
+
+                fclose (fp);
+                break;
+
+	case -1:
+
+                if (argc >= 2) {
+                        int i = 1;
+                        g_print ("Pre-generating HTMLs for the XML files entered on the command line\n");
+                        while (i <= argc -1 && argv[i]) {
+                                if (g_strrstr (argv[i], ".xml")) {
+                                        xml_list = g_list_append (xml_list, argv[i]);
+                                } else {
+                                        g_print("The file %s entered on the command line is not an XML file\n", argv[i]);
+                                }
+                                i++;
+                        }
+                }
+                break;
+
+	case '?':
+                g_print ("Usage: yelp-pregenerate [OPTIONS] \n\n"
+                         "-a :                 Pregenerate HTMLs for all XML files installed in \n                     the system\n"
+                         "-f <XML-LIST-FILE> : Pregenerate HTMLs for all the XML files specified in\n                     file XML-LIST-FILE. Enter full path of XML-LIST-FILE\n"
+                         "<XML_FILE(S)>....  : Enter one or more XML files to beconverted to \n                     HTML files on the command line\n\n");
+                exit (1);
+
+	default :
+                exit (1);	
+
+	}
+
+	for (index = xml_list; index; index = index->next) {
+		html_data = NULL;
+		error = NULL;
+
+		xml_url = (gchar *)index->data;
+
+		if (!g_file_test (xml_url, G_FILE_TEST_EXISTS)) {
+			g_print ("File %s to be parsed does not exist\n", xml_url);
+			continue;
+		}
+
+		command_line = g_strdup_printf ("%s/yelp-db2html %s", 
+                                                SERVERDIR,
+                                                xml_url);
+		
+		g_print ("Parsing %s\n", xml_url);
+
+		g_spawn_command_line_sync (command_line,
+					   &html_data,
+					   NULL,
+					   &exit_status,
+					   &error);
+
+		if (html_data) {
+			yelp_pregenerate_write_to_html (xml_url, html_data);
+                }
+	}
+
+	g_list_free (xml_list);
+	g_free (command_line);
+	g_free (html_data);
+
+	exit (0);
+}
+
+
+/* This function gets the list of XML help files installed in the system 
+ * by querying the Scrollkeeper database.
+ */
+
+gboolean
+yelp_pregenerate_xml_list_init (GNode *tree)
+{
+	gchar       *docpath;
+	gchar       *full_command;
+	xmlDoc      *doc;
+	const GList *node;
+	gboolean     success = FALSE;
+	gchar 	    *std_err;
+	gchar 	    *command, *argument;
+
+	g_return_val_if_fail (tree != NULL, FALSE);
+
+	seriesid_hash = g_hash_table_new_full (g_str_hash,
+					       g_str_equal,
+					       g_free, NULL);
+
+	docid_hash = g_hash_table_new_full (g_str_hash, g_str_equal,
+					    g_free, NULL);
+
+	doc = NULL;
+
+	for (node = gnome_i18n_get_language_list ("LC_MESSAGES"); node; node = node->next) {
+		command = "scrollkeeper-get-content-list";
+		argument = node->data;
+		full_command = g_strconcat (command, 
+					    " ", argument, NULL);
+
+		success = g_spawn_command_line_sync (full_command, 
+						     &docpath,
+						     &std_err, NULL, NULL);
+		g_free (full_command);
+		g_free (std_err);
+
+		if (!success) {
+			g_warning ("Didn't successfully run command: '%s %s'",
+			   	   command, argument);
+			return FALSE;
+		}
+
+		if (docpath) {
+			docpath = g_strchomp (docpath);
+			doc = xmlParseFile (docpath);
+			g_free (docpath);
+		}
+
+		if (doc) {
+			if (doc->xmlRootNode && 
+			    !tree_empty(doc->xmlRootNode->xmlChildrenNode)) {
+                                break;
+			} else {
+				xmlFreeDoc (doc);
+				doc = NULL;
+			}
+		}
+	}
+
+	if (doc) {
+
+                trim_empty_branches (doc->xmlRootNode);
+
+                parse_books (tree, doc);
+
+                xmlFreeDoc (doc);
+	}
+
+	return TRUE;
+}
+
+
+gboolean
+parse_books (GNode *tree, xmlDoc *doc)
+{
+	xmlNode  *node;
+	gboolean  success;
+	GNode    *book_node;
+
+	g_return_val_if_fail (tree != NULL, FALSE);
+
+	node = doc->xmlRootNode;
+
+	if (!node || !node->name ||
+	    g_ascii_strcasecmp (node->name, "ScrollKeeperContentsList")) {
+		g_warning ("Invalid ScrollKeeper XML Contents List!");
+		return FALSE;
+	}
+
+	book_node = g_node_append_data (tree,
+					section_new (YELP_SECTION_CATEGORY,
+					 	     "scrollkeeper"));
+
+	for (node = node->xmlChildrenNode; node; node = node->next) {
+		if (!g_ascii_strcasecmp (node->name, "sect")) {
+			success = parse_section (book_node, node);
+		}
+	}
+
+	return TRUE;
+}
+
+static gboolean
+parse_section (GNode *parent, xmlNode *xml_node)
+{
+	xmlNode *cur;
+	xmlChar *xml_str;
+	gchar   *name;
+	GNode   *node;
+	gchar   *docid;
+
+	/* Find the title */
+	for (cur = xml_node->xmlChildrenNode; cur; cur = cur->next) {
+		if (!g_ascii_strcasecmp (cur->name, "title")) {
+			xml_str = xmlNodeGetContent (cur);
+
+			if (xml_str) {
+				name = g_strdup (xml_str);
+				xmlFree (xml_str);
+			}
+		}
+	}
+
+	if (!name) {
+		g_warning ("Couldn't find name of the section");
+		return FALSE;
+	}
+
+	node = g_node_append_data (parent,
+				   section_new (YELP_SECTION_CATEGORY, name));
+
+	for (cur = xml_node->xmlChildrenNode; cur; cur = cur->next) {
+		if (!g_ascii_strcasecmp (cur->name, "sect")) {
+			parse_section (node, cur);
+		}
+		else if (!g_ascii_strcasecmp (cur->name, "doc")) {
+
+                        xml_str = xmlGetProp (cur, "docid");
+			if (xml_str) {
+				docid = g_strdup (xml_str);
+				xmlFree (xml_str);
+			}
+
+			parse_doc_source (node, cur, docid);
+		}
+	}
+
+	return TRUE;
+}
+
+
+static void
+parse_doc_source (GNode *parent, xmlNode *xml_node, gchar *docid)
+{
+	xmlNode *cur;
+	xmlChar *xml_str;
+	gchar   *docsource;
+
+	for (cur = xml_node->xmlChildrenNode; cur; cur = cur->next) {
+
+		if (!g_ascii_strcasecmp (cur->name, "docsource")) {
+			xml_str = xmlNodeGetContent (cur);
+			docsource = strip_scheme (xml_str, NULL);
+		
+			xml_list = g_list_append (xml_list, docsource);
+			xmlFree (xml_str);
+			break;
+		}
+	}
+}
+
+
+static gchar *
+strip_scheme(gchar *original_uri, gchar **scheme)
+{
+	gchar *new_uri;
+	gchar *point;
+
+	point = strstr (original_uri, ":");
+
+	if (!point) {
+		if (scheme) {
+			*scheme = NULL;
+		}
+
+		return g_strdup (original_uri);
+	}
+
+	if (scheme) {
+		*scheme = g_strndup(original_uri, point - original_uri);
+	}
+
+	new_uri = g_strdup (point + 1);
+
+	return new_uri;
+}
+
+
+Section *
+section_new (SectionType  type,
+             const gchar  *name)
+{ 
+	Section *section;
+
+	section = g_new0 (Section, 1);
+
+	section->type = type;
+
+	if (name) {
+		section->name = g_strdup (name);
+	} else {
+		section->name = g_strdup ("");
+	}
+
+	return section;
+}
+
+static gboolean
+trim_empty_branches (xmlNode *node)
+{
+	xmlNode  *child;
+	xmlNode  *next;
+	gboolean  empty;
+
+	if (!node) {
+		return TRUE;
+	}
+
+	for (child = node->xmlChildrenNode; child; child = next) {
+		next = child->next;
+
+		if (!g_ascii_strcasecmp (child->name, "sect")) {
+			empty = trim_empty_branches (child);
+			if (empty) {
+				xmlUnlinkNode (child);
+				xmlFreeNode (child);
+			}
+		}
+	}
+
+	for (child = node->xmlChildrenNode; child; child = child->next) {
+		if (!g_ascii_strcasecmp (child->name, "sect") ||
+		    !g_ascii_strcasecmp (child->name, "doc")) {
+			return FALSE;
+		}
+	}
+
+	return TRUE;
+}
+
+static gboolean
+tree_empty (xmlNode *cl_node)
+{
+	xmlNode  *node, *next;
+	gboolean  ret_val;
+
+	if (cl_node == NULL)
+		return TRUE;
+
+	for (node = cl_node; node != NULL; node = next) {
+		next = node->next;
+
+		if (!g_ascii_strcasecmp (node->name, "sect") &&
+                    node->xmlChildrenNode->next != NULL) {
+			ret_val = tree_empty (node->xmlChildrenNode->next);
+
+			if (!ret_val) {
+				return ret_val;
+			}
+		}
+
+		if (!g_ascii_strcasecmp (node->name, "doc")) {
+			return FALSE;
+		}
+	}
+
+	return TRUE;
+}
+
+/* Stores the result of XML to HTML conversion in the same directory where 
+ * the XML file resides.
+ */
+
+static gboolean
+yelp_pregenerate_write_to_html (gchar  *xml_url,
+				gchar  *html_data)
+{
+	gchar 	*pos;
+	GString *path;
+	gchar   *html_url;
+	gint 	 len = 0;
+	FILE    *fp;
+	
+	pos = g_strrstr (xml_url, ".xml");
+
+	len = pos - xml_url;
+
+	path = g_string_new (xml_url);
+
+	path = g_string_truncate (path, len);
+
+	path = g_string_append (path, ".html");
+
+	html_url = g_string_free (path, FALSE);
+
+	fp = fopen (html_url, "w+");
+
+	if (fp == NULL) {
+		g_print ("Error in opening file %s\n", html_url);
+
+		return FALSE;
+	}
+
+        g_print ("Writing output to %s\n", html_url);
+
+	fwrite (html_data, strlen (html_data), 1, fp);
+
+	fclose (fp);
+
+	return TRUE;
+}
diff --git a/src/yelp-pregenerate.h b/src/yelp-pregenerate.h
new file mode 100644
index 00000000..d468948f
--- /dev/null
+++ b/src/yelp-pregenerate.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2002 Sun Microsystems Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ */
+
+#ifndef __YELP_PREGENERATE_H__
+#define __YELP_PREGENERATE_H__ 
+
+typedef struct _Section   Section;
+
+#define SECTION(x) ((Section *) x)
+
+typedef enum {
+	YELP_SECTION_DOCUMENT_SECTION,
+	YELP_SECTION_DOCUMENT,
+	YELP_SECTION_CATEGORY,
+	YELP_SECTION_INDEX
+} SectionType;
+
+struct _Section {
+	gchar           *name;
+	SectionType     type;
+};
+
+gboolean  yelp_pregenerate_xml_list_init (GNode       	 *tree);
+
+#endif /* __YELP_PREGENERATE_H__*/
diff --git a/src/yelp-reader.c b/src/yelp-reader.c
index 6ca00367..6e19e8d6 100644
--- a/src/yelp-reader.c
+++ b/src/yelp-reader.c
@@ -725,9 +725,14 @@ yelp_reader_new ()
 gboolean
 yelp_reader_start (YelpReader *reader, YelpURI *uri)
 {
-        YelpReaderPriv   *priv;
+	YelpReaderPriv   *priv;
 	ReaderThreadData *th_data;
 	gint              stamp;
+	const gchar      *document = NULL;
+	gchar            *chunk = NULL;
+	gchar            *str_uri = NULL;
+	gchar             buffer[BUFFER_SIZE];
+	YelpURI	         *new_uri;
 	
 	g_return_val_if_fail (YELP_IS_READER (reader), FALSE);
 	g_return_val_if_fail (uri != NULL, FALSE);
@@ -751,49 +756,100 @@ yelp_reader_start (YelpReader *reader, YelpURI *uri)
 	th_data->uri    = yelp_uri_ref (uri);
 	th_data->stamp  = stamp;
 
-	if (yelp_uri_get_type (uri) == YELP_URI_TYPE_DOCBOOK_XML || 
-	    yelp_uri_get_type (uri) == YELP_URI_TYPE_DOCBOOK_SGML) {
-		const gchar *document;
-		gchar *chunk;
+	str_uri = yelp_uri_to_string (uri);
 
-		document = yelp_cache_lookup (yelp_uri_get_path (uri));
-		
-		if (document) {
-			if (yelp_uri_get_section (uri) &&
-			    strcmp (yelp_uri_get_section (uri), "")) {
-				chunk = reader_get_chunk (document, 
-							  yelp_uri_get_section (uri));
-			} else {
-				chunk = reader_get_chunk (document, "toc");
-			}
-		
-			if (chunk) {
-				ReaderQueueData *q_data;
-				
-				q_data = reader_q_data_new (reader, stamp, 
-							    READER_QUEUE_TYPE_START);
-				g_async_queue_push (priv->thread_queue, 
-						    q_data);
-
-				q_data = reader_q_data_new (reader, stamp, 
-							    READER_QUEUE_TYPE_DATA);
-
-				q_data->data = chunk;
-				g_async_queue_push (priv->thread_queue, 
-						    q_data);
-				
-				q_data = reader_q_data_new (reader, stamp, 
-							    READER_QUEUE_TYPE_FINISHED);
-
-				g_async_queue_push (priv->thread_queue, 
-						    q_data);
-
-				g_idle_add ((GSourceFunc) reader_idle_check_queue, th_data);
-				return TRUE;
+	if (str_uri && *str_uri) {
+		str_uri = look_for_html_help_file (str_uri);
+		new_uri = yelp_uri_new (str_uri);
+	}
+	else
+		new_uri = yelp_uri_copy (uri);
+
+	g_free (str_uri);
+
+	if (yelp_uri_get_type (new_uri) == YELP_URI_TYPE_DOCBOOK_XML ||
+	    yelp_uri_get_type (new_uri) == YELP_URI_TYPE_DOCBOOK_SGML) {
+
+		document = yelp_cache_lookup (yelp_uri_get_path (new_uri));
+	}
+
+        /* check if there is HTML cache. If found, use the HTML cache. */
+	else if (yelp_uri_get_type (new_uri) == YELP_URI_TYPE_HTML) {
+		GnomeVFSHandle   *handle;
+		GnomeVFSResult    result;
+		GString          *html_buffer;
+		GnomeVFSFileSize  n;
+
+		result = gnome_vfs_open (&handle,
+					 yelp_uri_get_path (new_uri),
+					 GNOME_VFS_OPEN_READ);
+
+		if (result != GNOME_VFS_OK) {
+			/* FIXME: Signal error */
+			yelp_uri_unref (new_uri);
+			return FALSE;
+		}
+
+		html_buffer = NULL;
+
+		while (TRUE) {
+			result = gnome_vfs_read (handle, buffer,
+						 BUFFER_SIZE, &n);
+
+			/* FIXME: Do some error checking */
+			if (result != GNOME_VFS_OK) {
+				break;
 			}
+
+			if (html_buffer == NULL)
+				html_buffer = g_string_new (g_strndup (buffer,
+							    n));
+			else
+				html_buffer = g_string_append (html_buffer,
+							       g_strndup (buffer,
+							       n));
 		}
+		document = html_buffer->str;
+		g_string_free (html_buffer, FALSE);
 	}
-	
+
+	if (document) {
+		if (yelp_uri_get_section (new_uri) &&
+		    strcmp (yelp_uri_get_section (new_uri), "")) {
+			chunk = reader_get_chunk (document,
+						  yelp_uri_get_section (new_uri));
+		} else {
+			chunk = reader_get_chunk (document, "toc");
+		}
+
+		if (chunk) {
+			ReaderQueueData *q_data;
+
+			q_data = reader_q_data_new (reader, stamp,
+						    READER_QUEUE_TYPE_START);
+			g_async_queue_push (priv->thread_queue,
+					    q_data);
+
+			q_data = reader_q_data_new (reader, stamp,
+						    READER_QUEUE_TYPE_DATA);
+
+			q_data->data = chunk;
+			g_async_queue_push (priv->thread_queue,
+					    q_data);
+
+			q_data = reader_q_data_new (reader, stamp,
+						    READER_QUEUE_TYPE_FINISHED);
+			g_async_queue_push (priv->thread_queue,
+					    q_data);
+
+			g_idle_add ((GSourceFunc) reader_idle_check_queue,
+				    th_data);
+
+			yelp_uri_unref (new_uri);
+			return TRUE;
+		}
+	}
+
 	g_timeout_add (100, (GSourceFunc) reader_idle_check_queue, th_data);
 
 	g_thread_create_full ((GThreadFunc) reader_start, th_data,
@@ -801,6 +857,9 @@ yelp_reader_start (YelpReader *reader, YelpURI *uri)
 			      TRUE,
 			      FALSE, G_THREAD_PRIORITY_NORMAL,
 			      NULL /* FIXME: check for errors */);
+
+	yelp_uri_unref (new_uri);
+
 	return FALSE;
 }
 
@@ -819,3 +878,79 @@ yelp_reader_cancel (YelpReader *reader)
 
 	STAMP_MUTEX_UNLOCK;
 }
+
+
+/* Given an XML file, look if there is a cached HTML file. If the HTML is
+ * newer than XML, return it. Else return XML only.
+ */
+
+gchar *
+look_for_html_help_file (gchar *url)
+{
+	gchar *sect, *pos;
+	int len=0;
+	GString *path;
+	char    *html_url, *xml_url;
+	char    *scheme;
+	struct stat html_stat, xml_stat;
+
+	if (g_strrstr (url, ".xml") == NULL)
+		return url;
+
+	path = g_string_new (url);
+	sect = g_strrstr (url, "?");
+
+	len = sect - url;
+	path = g_string_truncate (path, len);
+
+	scheme = g_strrstr (path->str, ":");
+
+	xml_url = g_strdup (scheme + 1);
+
+	pos = g_strrstr (path->str, ".xml");
+
+	if (pos == NULL) {
+		g_string_free (path, TRUE);
+		g_free (xml_url);
+
+		return url;
+	}
+
+	len = pos - path->str;
+
+	path = g_string_truncate (path, len);
+
+	path = g_string_append (path, ".html");
+
+	scheme = g_strrstr (path->str, ":");
+
+	html_url = g_strdup (scheme + 1);
+
+	if (g_file_test (html_url, G_FILE_TEST_EXISTS)) {
+
+		stat (html_url, &html_stat);
+		stat (xml_url, &xml_stat);
+
+		g_free (xml_url);
+		g_free (html_url);
+
+		if (html_stat.st_mtime >= xml_stat.st_mtime) {
+
+			if (sect)
+				path = g_string_append (path, sect);
+
+			return g_string_free (path, FALSE);
+		}
+		else {
+			g_string_free (path, TRUE);
+			return url;
+		}
+	}
+	else {
+		g_free (xml_url);
+		g_free (html_url);
+		g_string_free (path, TRUE);
+
+		return url;
+	}
+}
diff --git a/src/yelp-reader.h b/src/yelp-reader.h
index d545c87a..01b3250f 100644
--- a/src/yelp-reader.h
+++ b/src/yelp-reader.h
@@ -65,5 +65,6 @@ YelpReader *     yelp_reader_new          (void);
 gboolean         yelp_reader_start        (YelpReader *reader,
 					   YelpURI    *uri);
 void             yelp_reader_cancel       (YelpReader *reader);
+gchar *          look_for_html_help_file  (gchar      *xml_uri);
 
 #endif /* __YELP_READER_H__ */