/*
** Copyright (c) 2012 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the Simplified BSD License (also
** known as the "2-Clause License" or "FreeBSD License".)
** 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.
**
** Author contact information:
** drh@hwaci.com
** http://www.hwaci.com/drh/
**
*******************************************************************************
**
** This file contains callbacks for the markdown parser that generate
** XHTML output.
*/
#include "config.h"
#include "markdown_html.h"
#if INTERFACE
void markdown_to_html(
struct Blob *input_markdown,
struct Blob *output_title,
struct Blob *output_body);
#endif /* INTERFACE */
/* INTER_BLOCK -- skip a line between block level elements */
#define INTER_BLOCK(ob) \
do { if( blob_size(ob)>0 ) blob_append(ob, "\n", 1); } while (0)
/* BLOB_APPEND_LITTERAL -- append a string litteral to a blob */
#define BLOB_APPEND_LITTERAL(blob, litteral) \
blob_append((blob), "" litteral, (sizeof litteral)-1)
/*
* The empty string in the second argument leads to a syntax error
* when the macro is not used with a string litteral. Unfortunately
* the error is not overly explicit.
*/
/* BLOB_APPEND_BLOB -- append blob contents to another */
#define BLOB_APPEND_BLOB(dest, src) \
blob_append((dest), blob_buffer(src), blob_size(src))
/* HTML escape */
static void html_escape(struct Blob *ob, const char *data, size_t size){
size_t beg = 0, i = 0;
while( i<size ){
beg = i;
while( i<size
&& data[i]!='<'
&& data[i]!='>'
&& data[i]!='"'
&& data[i]!='&'
){
i++;
}
blob_append(ob, data+beg, i-beg);
while( i<size ){
if( data[i]=='<' ){
BLOB_APPEND_LITTERAL(ob, "<");
}else if( data[i]=='>' ){
BLOB_APPEND_LITTERAL(ob, ">");
}else if( data[i]=='&' ){
BLOB_APPEND_LITTERAL(ob, "&");
}else if( data[i]=='"' ){
BLOB_APPEND_LITTERAL(ob, """);
}else{
break;
}
i++;
}
}
}
/* HTML block tags */
static void html_raw_block(struct Blob *ob, struct Blob *text, void *opaque){
char *data = blob_buffer(text);
size_t first = 0, size = blob_size(text);
INTER_BLOCK(ob);
while( first<size && data[first]=='\n' ) first++;
while( size>first && data[size-1]=='\n' ) size--;
blob_append(ob, data+first, size-first);
BLOB_APPEND_LITTERAL(ob, "\n");
}
static void html_blockcode(struct Blob *ob, struct Blob *text, void *opaque){
INTER_BLOCK(ob);
BLOB_APPEND_LITTERAL(ob, "<pre><code>");
html_escape(ob, blob_buffer(text), blob_size(text));
BLOB_APPEND_LITTERAL(ob, "</code></pre>\n");
}
static void html_blockquote(struct Blob *ob, struct Blob *text, void *opaque){
INTER_BLOCK(ob);
BLOB_APPEND_LITTERAL(ob, "<blockquote>\n");
BLOB_APPEND_BLOB(ob, text);
BLOB_APPEND_LITTERAL(ob, "</blockquote>\n");
}
static void html_header(
struct Blob *ob,
struct Blob *text,
int level,
void *opaque
){
struct Blob *title = opaque;
/* The first header at the beginning of a text is considered as
* a title and not output. */
if( blob_size(ob)==0 && blob_size(title)==0 ){
BLOB_APPEND_BLOB(title, text);
return;
}
INTER_BLOCK(ob);
blob_appendf(ob, "<h%d>", level);
BLOB_APPEND_BLOB(ob, text);
blob_appendf(ob, "</h%d>", level);
}
static void html_hrule(struct Blob *ob, void *opaque){
INTER_BLOCK(ob);
BLOB_APPEND_LITTERAL(ob, "<hr />\n");
}
static void html_list(
struct Blob *ob,
struct Blob *text,
int flags,
void *opaque
){
char ol[] = "ol";
char ul[] = "ul";
char *tag = (flags & MKD_LIST_ORDERED) ? ol : ul;
INTER_BLOCK(ob);
blob_appendf(ob, "<%s>\n", tag);
BLOB_APPEND_BLOB(ob, text);
blob_appendf(ob, "</%s>\n", tag);
}
static void html_list_item(
struct Blob *ob,
struct Blob *text,
int flags,
void *opaque
){
char *text_data = blob_buffer(text);
size_t text_size = blob_size(text);
while( text_size>0 && text_data[text_size-1]=='\n' ) text_size--;
BLOB_APPEND_LITTERAL(ob, "<li>");
blob_append(ob, text_data, text_size);
BLOB_APPEND_LITTERAL(ob, "</li>\n");
}
static void html_paragraph(struct Blob *ob, struct Blob *text, void *opaque){
INTER_BLOCK(ob);
BLOB_APPEND_LITTERAL(ob, "<p>");
BLOB_APPEND_BLOB(ob, text);
BLOB_APPEND_LITTERAL(ob, "</p>\n");
}
static void html_table(
struct Blob *ob,
struct Blob *head_row,
struct Blob *rows,
void *opaque
){
INTER_BLOCK(ob);
BLOB_APPEND_LITTERAL(ob, "<table>\n");
if( head_row && blob_size(head_row)>0 ){
BLOB_APPEND_LITTERAL(ob, "<thead>\n");
BLOB_APPEND_BLOB(ob, head_row);
BLOB_APPEND_LITTERAL(ob, "</thead>\n<tbody>\n");
}
if( rows ){
BLOB_APPEND_BLOB(ob, rows);
}
if( head_row && blob_size(head_row)>0 ){
BLOB_APPEND_LITTERAL(ob, "</tbody>\n");
}
BLOB_APPEND_LITTERAL(ob, "</table>\n");
}
static void html_table_cell(
struct Blob *ob,
struct Blob *text,
int flags,
void *opaque
){
if( flags & MKD_CELL_HEAD ){
BLOB_APPEND_LITTERAL(ob, " <th");
}else{
BLOB_APPEND_LITTERAL(ob, " <td");
}
switch( flags & MKD_CELL_ALIGN_MASK ){
case MKD_CELL_ALIGN_LEFT: {
BLOB_APPEND_LITTERAL(ob, " align=\"left\"");
break;
}
case MKD_CELL_ALIGN_RIGHT: {
BLOB_APPEND_LITTERAL(ob, " align=\"right\"");
break;
}
case MKD_CELL_ALIGN_CENTER: {
BLOB_APPEND_LITTERAL(ob, " align=\"center\"");
break;
}
}
BLOB_APPEND_LITTERAL(ob, ">");
BLOB_APPEND_BLOB(ob, text);
if( flags & MKD_CELL_HEAD ){
BLOB_APPEND_LITTERAL(ob, "</th>\n");
}else{
BLOB_APPEND_LITTERAL(ob, "</td>\n");
}
}
static void html_table_row(
struct Blob *ob,
struct Blob *cells,
int flags,
void *opaque
){
BLOB_APPEND_LITTERAL(ob, " <tr>\n");
BLOB_APPEND_BLOB(ob, cells);
BLOB_APPEND_LITTERAL(ob, " </tr>\n");
}
/* HTML span tags */
static int html_raw_span(struct Blob *ob, struct Blob *text, void *opaque){
BLOB_APPEND_BLOB(ob, text);
return 1;
}
static int html_autolink(
struct Blob *ob,
struct Blob *link,
enum mkd_autolink type,
void *opaque
){
if( !link || blob_size(link)<=0 ) return 0;
BLOB_APPEND_LITTERAL(ob, "<a href=\"");
if( type==MKDA_IMPLICIT_EMAIL ) BLOB_APPEND_LITTERAL(ob, "mailto:");
html_escape(ob, blob_buffer(link), blob_size(link));
BLOB_APPEND_LITTERAL(ob, "\">");
if( type==MKDA_EXPLICIT_EMAIL && blob_size(link)>7 ){
/* remove "mailto:" from displayed text */
html_escape(ob, blob_buffer(link)+7, blob_size(link)-7);
}else{
html_escape(ob, blob_buffer(link), blob_size(link));
}
BLOB_APPEND_LITTERAL(ob, "</a>");
return 1;
}
static int html_code_span(struct Blob *ob, struct Blob *text, void *opaque){
BLOB_APPEND_LITTERAL(ob, "<code>");
html_escape(ob, blob_buffer(text), blob_size(text));
BLOB_APPEND_LITTERAL(ob, "</code>");
return 1;
}
static int html_double_emphasis(
struct Blob *ob,
struct Blob *text,
char c,
void *opaque
){
BLOB_APPEND_LITTERAL(ob, "<strong>");
BLOB_APPEND_BLOB(ob, text);
BLOB_APPEND_LITTERAL(ob, "</strong>");
return 1;
}
static int html_emphasis(
struct Blob *ob,
struct Blob *text,
char c,
void *opaque
){
BLOB_APPEND_LITTERAL(ob, "<em>");
BLOB_APPEND_BLOB(ob, text);
BLOB_APPEND_LITTERAL(ob, "</em>");
return 1;
}
static int html_image(
struct Blob *ob,
struct Blob *link,
struct Blob *title,
struct Blob *alt,
void *opaque
){
BLOB_APPEND_LITTERAL(ob, "<img src=\"");
html_escape(ob, blob_buffer(link), blob_size(link));
BLOB_APPEND_LITTERAL(ob, "\" alt=\"");
html_escape(ob, blob_buffer(alt), blob_size(alt));
if( title && blob_size(title)>0 ){
BLOB_APPEND_LITTERAL(ob, "\" title=\"");
html_escape(ob, blob_buffer(title), blob_size(title));
}
BLOB_APPEND_LITTERAL(ob, "\" />");
return 1;
}
static int html_line_break(struct Blob *ob, void *opaque){
BLOB_APPEND_LITTERAL(ob, "<br />\n");
return 1;
}
static int html_link(
struct Blob *ob,
struct Blob *link,
struct Blob *title,
struct Blob *content,
void *opaque
){
BLOB_APPEND_LITTERAL(ob, "<a href=\"");
html_escape(ob, blob_buffer(link), blob_size(link));
if( title && blob_size(title)>0 ){
BLOB_APPEND_LITTERAL(ob, "\" title=\"");
html_escape(ob, blob_buffer(title), blob_size(title));
}
BLOB_APPEND_LITTERAL(ob, "\">");
BLOB_APPEND_BLOB(ob, content);
BLOB_APPEND_LITTERAL(ob, "</a>");
return 1;
}
static int html_triple_emphasis(
struct Blob *ob,
struct Blob *text,
char c,
void *opaque
){
BLOB_APPEND_LITTERAL(ob, "<strong><em>");
BLOB_APPEND_BLOB(ob, text);
BLOB_APPEND_LITTERAL(ob, "</em></strong>");
return 1;
}
static void html_normal_text(struct Blob *ob, struct Blob *text, void *opaque){
html_escape(ob, blob_buffer(text), blob_size(text));
}
void markdown_to_html(
struct Blob *input_markdown,
struct Blob *output_title,
struct Blob *output_body
){
struct mkd_renderer html_renderer = {
0, 0, /* no prolog or epilog */
/* block level elements */
html_blockcode,
html_blockquote,
html_raw_block,
html_header,
html_hrule,
html_list,
html_list_item,
html_paragraph,
html_table,
html_table_cell,
html_table_row,
/* span level elements */
html_autolink,
html_code_span,
html_double_emphasis,
html_emphasis,
html_image,
html_line_break,
html_link,
html_raw_span,
html_triple_emphasis,
/* low level elements */
0, /* entities are copied verbatim */
html_normal_text,
/* misc. parameters */
64, /* maximum stack */
"*_", /* emphasis characters */
output_title /* opaque data */
};
blob_reset(output_title);
blob_reset(output_body);
markdown(output_body, input_markdown, &html_renderer);
}