/src/mupdf/source/html/office.c

Source
// Copyright (C) 2023-2026 Artifex Software, Inc.
//
// This file is part of MuPDF.
//
// MuPDF is free software: you can redistribute it and/or modify it under the
// terms of the GNU Affero General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// MuPDF 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 Affero General Public License for more
// details.
//
// You should have received a copy of the GNU Affero General Public License
// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
//
// Alternative licensing terms are available from the licensor.
// For commercial licensing, see <https://www.artifex.com/> or contact
// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
// CA 94129, USA, for further information.

#include "mupdf/fitz.h"
#include "html-imp.h"

#include <limits.h>

//#define DEBUG_OFFICE_TO_HTML

/* Defaults are all 0's. FIXME: Very subject to change. Possibly might be removed entirely. */
typedef struct
{
  int output_page_numbers;
  int output_sheet_names;
  int output_cell_markers;
  int output_cell_row_markers;
  int output_cell_names;
  int output_formatting;
  int output_filenames;
  int output_errors;
}
fz_office_to_html_opts;

typedef struct
{
  fz_office_to_html_opts opts;

  fz_output *out;

  int page;

  /* State for if we are parsing a sheet. */
  /* The last column label we have to send. */
  char *label;
  /* Columns are numbered from 1. */
  /* The column we are at. */
  int col_at;
  /* The column we last signalled. If this is 0, then we haven't
   * even started a row yet. */
  int col_signalled;

  /* If we are currently processing a spreadsheet, store the current
   * sheets name here. */
  const char *sheet_name;

  fz_list(char *, shared_strings);

  fz_list(char *, footnotes);

  char *title;
} doc_info;

static void
doc_escape(fz_context *ctx, fz_output *output, const char *str_)
{
  const unsigned char *str = (const unsigned char *)str_;
  int c;

  if (!str)
    return;

  while ((c = *str++) != 0)
  {
    if (c == '&')
    {
      fz_write_string(ctx, output, "&amp;");
    }
    else if (c == '<')
    {
      fz_write_string(ctx, output, "&lt;");
    }
    else if (c == '>')
    {
      fz_write_string(ctx, output, "&gt;");
    }
    else
    {
      /* We get utf-8 in, just parrot it out again. */
      fz_write_byte(ctx, output, c);
    }
  }
}

static void
show_text(fz_context *ctx, fz_xml *top, doc_info *info)
{
  fz_xml *pos = top;
  fz_xml *next;

  while (pos)
  {
    doc_escape(ctx, info->out, fz_xml_text(pos));

    if (fz_xml_is_tag(pos, "lineBreak"))
    {
      fz_write_string(ctx, info->out, "\n");
    }
    else if (fz_xml_is_tag(pos, "tab"))
    {
      fz_write_string(ctx, info->out, "\t");
    }
    else if (fz_xml_is_tag(pos, "lastRenderedPageBreak"))
    {
      info->page++;
    }

    /* Always try to move down. */
    next = fz_xml_down(pos);
    if (next)
    {
      /* We can move down, easy! */
      pos = next;
      continue;
    }

    if (pos == top)
      break;

    /* We can't move down, try moving to next. */
    next = fz_xml_next(pos);
    if (next)
    {
      /* We can move to next, easy! */
      pos = next;
      continue;
    }

    /* If we can't go down, or next, pop up until we
     * find somewhere we can go next from. */
    while (1)
    {
      /* OK. So move up. */
      pos = fz_xml_up(pos);
      /* Check for hitting the top. */
      if (pos == top)
        pos = NULL;
      if (pos == NULL)
        break;
      /* We've returned to a node. See if it's a 'p'. */
      if (fz_xml_is_tag(pos, "p"))
      {
        fz_write_string(ctx, info->out, "\n");
      }
      next = fz_xml_next(pos);
      if (next)
      {
        pos = next;
        break;
      }
    }
  }
}

static void
show_footnote(fz_context *ctx, fz_xml *v, doc_info *info)
{
  int n = fz_atoi(fz_xml_att(v, "w:id"));

  if (n < 0 || n >= info->footnotes_len)
    return;

  if (info->footnotes[n] == NULL ||
    info->footnotes[n][0] == 0)
    return;

  /* Then send the strings. */
  doc_escape(ctx, info->out, info->footnotes[n]);
}

static void
process_doc_stream(fz_context *ctx, fz_xml *xml, doc_info *info, int do_pages)
{
  fz_xml *pos;
  fz_xml *next;
  const char *paragraph_style = NULL;
  const char *inline_style = NULL;

#ifdef DEBUG_OFFICE_TO_HTML
  fz_write_printf(ctx, fz_stddbg(ctx), "process_doc_stream:\n");
  fz_output_xml(ctx, fz_stddbg(ctx), xml, 0);
#endif

  /* First off, see if we can do page numbers. */
  if (do_pages)
  {
    pos = fz_xml_find_dfs(xml, "lastRenderedPageBreak", NULL, NULL);
    if (pos)
    {
      /* We *can* do page numbers, so start here. */
      fz_write_string(ctx, info->out, "<div id=\"page1\">\n");
      info->page = 1;
    }
  }

  /* Now walk the tree for real. */
  pos = xml;
  while (pos)
  {
    /* When we arrive on a node, check if it's a 't'. */
    if (fz_xml_is_tag(pos, "t"))
    {
      show_text(ctx, pos, info);
      /* Do NOT go down, we've already dealt with that. */
    }
    else if (fz_xml_is_tag(pos, "br"))
    {
      if (paragraph_style && strcmp(paragraph_style, "pre"))
      {
        fz_write_printf(ctx, info->out, "<br/>\n");
      }
      else
      {
        fz_write_printf(ctx, info->out, "\n");
      }
    }
    else if (fz_xml_is_tag(pos, "footnoteReference"))
    {
      show_footnote(ctx, pos, info);
      /* Do NOT go down, we've already dealt with that. */
    }
    else if (fz_xml_is_tag(pos, "tabs"))
    {
      /* Don't walk through tabs, or we will hit lots of 'tab' entries and
       * output incorrect information. */
    }
    else if (fz_xml_is_tag(pos, "pStyle"))
    {
      /* Should prob fix fz_xml_*() to strip namespace prefix
      from attributes, to match what it does for tag names.
      */
      paragraph_style = fz_xml_att(pos, "w:val");
      if (paragraph_style)
      {
        if (!strcmp(paragraph_style, "BodyText"))
          paragraph_style = NULL;
        else if (!strcmp(paragraph_style, "Heading1"))
          paragraph_style = "h1";
        else if (!strcmp(paragraph_style, "Heading2"))
          paragraph_style = "h2";
        else if (!strcmp(paragraph_style, "Heading3"))
          paragraph_style = "h3";
        else if (!strcmp(paragraph_style, "Heading4"))
          paragraph_style = "h4";
        else if (!strcmp(paragraph_style, "Heading5"))
          paragraph_style = "h5";
        else if (!strcmp(paragraph_style, "Heading6"))
          paragraph_style = "h6";
        else if (!strcmp(paragraph_style, "SourceCode"))
          paragraph_style = "pre";
        else
          paragraph_style = NULL;

        if (paragraph_style)
          fz_write_printf(ctx, info->out, "<%s>", paragraph_style);
      }
    }
    else if (fz_xml_is_tag(pos, "rStyle"))
    {
      inline_style = fz_xml_att(pos, "w:val");
      if (inline_style)
      {
        if (!strcmp(inline_style, "VerbatimChar"))
          inline_style = "tt";
        else
        {
          if (0)
            fz_write_printf(ctx, info->out, "<!-- %s -->", inline_style);
          inline_style = NULL;
        }
        if (inline_style)
          fz_write_printf(ctx, info->out, "<%s>", inline_style);
      }
    }
    else
    {
      fz_xml *down;
      if (fz_xml_is_tag(pos, "lineBreak"))
      {
        fz_write_string(ctx, info->out, "\n");
      }
      else if (fz_xml_is_tag(pos, "p"))
      {
        fz_write_string(ctx, info->out, "<p>");
      }
      else if (fz_xml_is_tag(pos, "tab"))
      {
        fz_write_string(ctx, info->out, "\t");
      }
      else if (do_pages && fz_xml_is_tag(pos, "lastRenderedPageBreak"))
      {
        if (info->page)
          fz_write_string(ctx, info->out, "\n</div>\n");
        info->page++;
        fz_write_printf(ctx, info->out, "<div id=\"page%d\">\n", info->page);
      }
      /* Try to move down. */
      down = fz_xml_down(pos);
      if (down)
      {
        /* We can move down, easy! */
        pos = down;
        continue;
      }
    }
    /* Try moving to next. */
    next = fz_xml_next(pos);
    if (next)
    {
      /* We can move to next, easy! */
      pos = next;
      continue;
    }

    /* If we can't go down, or next, pop up until we
     * find somewhere we can go next from. */
    while (1)
    {
      /* OK. So move up. */
      pos = fz_xml_up(pos);
      /* Check for hitting the top. */
      if (pos == NULL)
        break;
      /* We've returned to a node. See if it's a 'p'. */
      if (fz_xml_is_tag(pos, "p"))
      {
        if (paragraph_style)
        {
          fz_write_printf(ctx, info->out, "</%s>", paragraph_style);
          paragraph_style = NULL;
        }
        fz_write_string(ctx, info->out, "</p>\n");
      }
      else if (fz_xml_is_tag(pos, "r"))
      {
        /* Seems to be pseudo-close for rStyle. */
        if (inline_style)
        {
          fz_write_printf(ctx, info->out, "</%s>", inline_style);
          inline_style = NULL;
        }
      }
      next = fz_xml_next(pos);
      if (next)
      {
        pos = next;
        break;
      }
    }
  }

  if (do_pages && info->page)
    fz_write_string(ctx, info->out, "\n</div>\n");
}

static void
process_item(fz_context *ctx, fz_archive *arch, const char *file, doc_info *info, int do_pages)
{
  fz_xml *xml = fz_parse_xml_archive_entry(ctx, arch, file, 1);

  fz_try(ctx)
    process_doc_stream(ctx, xml, info, do_pages);
  fz_always(ctx)
    fz_drop_xml(ctx, xml);
  fz_catch(ctx)
    fz_rethrow(ctx);
}

static void
process_rootfile(fz_context *ctx, fz_archive *arch, const char *file, doc_info *info)
{
  fz_xml *xml = fz_parse_xml_archive_entry(ctx, arch, file, 0);

  fz_try(ctx)
  {
    /* FIXME: Should really search for these just inside 'spine'. */
    fz_xml *pos = fz_xml_find_dfs(xml, "itemref", NULL, NULL);
    while (pos)
    {
      char *idref = fz_xml_att(pos, "idref");
      fz_xml *item = fz_xml_find_dfs(xml, "item", "id", idref);
      while (item)
      {
        char *type = fz_xml_att(item, "media-type");
        char *href = fz_xml_att(item, "href");
        if (type && href && !strcmp(type, "application/xml"))
        {
          process_item(ctx, arch, href, info, 1);
        }
        item = fz_xml_find_next_dfs(pos, "item", "id", idref);
      }
      pos = fz_xml_find_next_dfs(pos, "itemref", NULL, NULL);
    }
  }
  fz_always(ctx)
    fz_drop_xml(ctx, xml);
  fz_catch(ctx)
    fz_rethrow(ctx);
}

/* XLSX support */
static char *
make_rel_name(fz_context *ctx, const char *file)
{
  size_t z = strlen(file);
  char *s = fz_malloc(ctx, z + 12);
  char *t;
  const char *p;
  const char *slash = file;

  for (p = file; *p != 0; p++)
    if (*p == '/')
      slash = p+1;

  t = s;
  if (slash != file)
  {
    memcpy(t, file, slash - file);
    t += slash - file;
  }
  memcpy(t, "_rels/", 6);
  t += 6;
  memcpy(t, file + (slash - file), z - (slash - file));
  t += z - (slash - file);
  memcpy(t, ".rels", 6);

  return s;
}

static char *lookup_rel(fz_context *ctx, fz_xml *rels, const char *id)
{
  fz_xml *pos;

  if (id == NULL)
    return NULL;

  pos = fz_xml_find_dfs(rels, "Relationship", NULL, NULL);
  while (pos)
  {
    char *id2 = fz_xml_att(pos, "Id");

    if (id2 && !strcmp(id, id2))
      return fz_xml_att(pos, "Target");

    pos = fz_xml_find_next_dfs(pos, "Relationship", NULL, NULL);
  }

  return NULL;
}

static void
send_cell_formatting(fz_context *ctx, doc_info *info)
{
  if (info->col_signalled == 0)
  {
    fz_write_string(ctx, info->out, "<tr>\n");
    info->col_signalled = 1;
    if (info->col_at > 1)
      fz_write_string(ctx, info->out, "<td>");
  }

  /* Send the label */
  while (info->col_signalled < info->col_at)
  {
    fz_write_string(ctx, info->out, "</td>");
    info->col_signalled++;
    if (info->col_signalled < info->col_at)
      fz_write_string(ctx, info->out, "<td>");
  }
  if (info->sheet_name && info->sheet_name[0])
    fz_write_printf(ctx, info->out, "<td id=\"%s!%s\">", info->sheet_name, info->label);
  else
    fz_write_printf(ctx, info->out, "<td id=\"%s\">", info->label);
}

static void
show_shared_string(fz_context *ctx, fz_xml *v, doc_info *info)
{
  const char *t = fz_xml_text(fz_xml_down(v));
  int n = fz_atoi(t);

  if (n < 0 || n >= info->shared_strings_len)
    return;

  if (info->shared_strings[n] == NULL ||
    info->shared_strings[n][0] == 0)
    return;

  send_cell_formatting(ctx, info);
  /* Then send the strings. */
  doc_escape(ctx, info->out, info->shared_strings[n]);
}

/* Google docs maxes columns out at ZZZ = 18278.
 * Excel (and similar) max out at XFD = 16384.
 */
#define MAX_GOOGLE_DOC_COLUMN 18278

static int
col_from_label(const char *label)
{
  int col = 0;
  int len = 26;
  int base = 0;

  /* If we can't read the column, return 0. */
  if (label == NULL || *label < 'A' || *label > 'Z')
    return 0;

  /*  Each section (A-Z, AA-ZZ, AAA-ZZZ etc) is of len 'len', and starts
   *  at base index 'base'. Each section is 26 times as long, and starts
   *  at base + len from the previous section.
   *
   *  A:  col = 26 * 0 + 0 + 0
   *  AA: col = (26 * 0 + 0 + 0) * 26 + 0 + 26 = 26
   *  AAA:  col = (((26 * 0 + 0 + 0) * 26 + 0 + 26)*26 + 0 + 26*26 = 26 + 26 * 26
   */
  do
  {
    col = 26 * col + (*label++) - 'A' + base;
    if (col > MAX_GOOGLE_DOC_COLUMN)
      return 0;
    base += len;
    len *= 26;
  }
  while (*label >= 'A' && *label <= 'Z');

  return col+1;
}

static void
show_cell_text(fz_context *ctx, fz_xml *top, doc_info *info)
{
  fz_xml *pos = top;
  fz_xml *next;

  while (pos)
  {
    char *text = fz_xml_text(pos);

    if (text)
    {
      send_cell_formatting(ctx, info);
      doc_escape(ctx, info->out, text);
    }

    /* Always try to move down. */
    next = fz_xml_down(pos);
    if (next)
    {
      /* We can move down, easy! */
      pos = next;
      continue;
    }

    if (pos == top)
      break;

    /* We can't move down, try moving to next. */
    next = fz_xml_next(pos);
    if (next)
    {
      /* We can move to next, easy! */
      pos = next;
      continue;
    }

    /* If we can't go down, or next, pop up until we
     * find somewhere we can go next from. */
    while (1)
    {
      /* OK. So move up. */
      pos = fz_xml_up(pos);
      /* Check for hitting the top. */
      if (pos == top)
        pos = NULL;
      if (pos == NULL)
        break;
      next = fz_xml_next(pos);
      if (next)
      {
        pos = next;
        break;
      }
    }
  }
}

static void
arrived_at_cell(fz_context *ctx, doc_info *info, const char *label)
{
  int col;

  /* If we have a label queued, and no label is given here, then we're
   * processing a 'cell' callback after having had a 'cellname'
   * callback. So don't signal it twice! */
  if (label == NULL && info->label)
    return;

  col = label ? col_from_label(label) : 0;

  fz_free(ctx, info->label);
  info->label = NULL;
  info->label = label ? fz_strdup(ctx, label) : NULL;
  info->col_at = col;
}

static void
show_cell(fz_context *ctx, fz_xml *cell, doc_info *info)
{
  char *t = fz_xml_att(cell, "t");
  fz_xml *v = fz_xml_find_down(cell, "v");
  const char *r = fz_xml_att(cell, "r");

  arrived_at_cell(ctx, info, r);
  if (t && t[0] == 's' && t[1] == 0)
    show_shared_string(ctx, v, info);
  else
    show_cell_text(ctx, v, info);
}

static void
new_row(fz_context *ctx, doc_info *info)
{
  if (info->col_signalled)
  {
    /* We've sent at least one cell. So need to close the
     * td and tr */
    fz_write_string(ctx, info->out, "</td>\n</tr>\n");
  }
  else
  {
    /* We've not sent anything for this row. Keep the counts
     * correct. */
    fz_write_string(ctx, info->out, "<tr></tr>\n");
  }
  info->col_at = 1;
  info->col_signalled = 0;
  fz_free(ctx, info->label);
  info->label = NULL;
}

static void
process_sheet(fz_context *ctx, fz_archive *arch, const char *name, const char *file, doc_info *info)
{
  fz_xml *xml = fz_parse_xml_archive_entry(ctx, arch, file, 1);

#ifdef DEBUG_OFFICE_TO_HTML
  fz_write_printf(ctx, fz_stddbg(ctx), "process_sheet:\n");
  fz_output_xml(ctx, fz_stddbg(ctx), xml, 0);
#endif

  fz_write_printf(ctx, info->out, "<table id=\"%s\">\n", name);

  info->sheet_name = name;
  info->col_at = 0;
  info->col_signalled = 0;

  fz_try(ctx)
  {
    fz_xml *pos = xml;
    fz_xml *next;

    while (pos)
    {
      /* When we arrive on a node, check if it's a cell. */
      if (fz_xml_is_tag(pos, "c"))
      {
        show_cell(ctx, pos, info);
        /* Do NOT go down, we've already dealt with that. */
      }
      else
      {
        /* Try to move down. */
        next = fz_xml_down(pos);
        if (next)
        {
          /* We can move down, easy! */
          pos = next;
          continue;
        }
      }
      /* Try moving to next. */
      next = fz_xml_next(pos);
      if (next)
      {
        /* We can move to next, easy! */
        pos = next;
        continue;
      }

      /* If we can't go down, or next, pop up until we
       * find somewhere we can go next from. */
      while (1)
      {
        /* OK. So move up. */
        pos = fz_xml_up(pos);
        /* Check for hitting the top. */
        if (pos == NULL)
          break;

        /* We've returned to a node. See if it's a 'row'. */
        if (fz_xml_is_tag(pos, "row"))
          new_row(ctx, info);

        next = fz_xml_next(pos);
        if (next)
        {
          pos = next;
          break;
        }
      }
    }
    if (info->col_signalled)
      fz_write_printf(ctx, info->out, "</td>\n</tr>\n");
    fz_write_printf(ctx, info->out, "</table>\n");
  }
  fz_always(ctx)
    fz_drop_xml(ctx, xml);
  fz_catch(ctx)
    fz_rethrow(ctx);
}

static void
process_slide(fz_context *ctx, fz_archive *arch, const char *file, doc_info *info)
{
  fz_write_printf(ctx, info->out, "<div id=\"slide%d\">\n", info->page++);
  process_item(ctx, arch, file, info, 0);
  fz_write_printf(ctx, info->out, "</div>\n");
}

static char *
make_absolute_path(fz_context *ctx, const char *abs, const char *rel)
{
  const char *a = abs;
  const char *aslash = a;
  int up = 0;
  size_t z1, z2;
  char *s;

  if (rel == NULL)
    return NULL;
  if (abs == NULL || *rel == '/')
    return fz_strdup(ctx, rel);

  for (a = abs; *a != 0; a++)
    if (*a == '/')
      aslash = a+1;

  while (rel[0] == '.')
  {
    if (rel[1] == '/')
      rel += 2;
    else if (rel[1] == '.' && rel[2] == '/')
      rel += 3, up++;
    else
      fz_throw(ctx, FZ_ERROR_FORMAT, "Unresolvable path");
  }
  if (rel[0] == 0)
    fz_throw(ctx, FZ_ERROR_FORMAT, "Unresolvable path");

  while (up)
  {
    while (aslash != abs && aslash[-1] != '/')
      aslash--;

    up--;
  }

  z1 = aslash - abs;
  z2 = strlen(rel);
  s = fz_malloc(ctx, z1 + z2 + 1);
  if (z1)
    memcpy(s, abs, z1);
  memcpy(s+z1, rel, z2+1);

  return s;
}

static char *
collate_t_content(fz_context *ctx, fz_xml *top)
{
  char *val = NULL;
  fz_xml *next;
  fz_xml *pos = fz_xml_down(top);

  while (pos != top)
  {
    /* Capture all the 't' content. */
    if (fz_xml_is_tag(pos, "t"))
    {
      /* Remember the content. */
      char *s = fz_xml_text(fz_xml_down(pos));

      if (s == NULL)
      {
        /* Do nothing */
      }
      else if (val == NULL)
        val = fz_strdup(ctx, s);
      else
      {
        char *val2;
        size_t z1 = strlen(val);
        size_t z2 = strlen(s) + 1;
        fz_try(ctx)
        {
          val2 = fz_malloc(ctx, z1 + z2);
        }
        fz_catch(ctx)
        {
          fz_free(ctx, val);
          fz_rethrow(ctx);
        }
        memcpy(val2, val, z1);
        memcpy(val2 + z1, s, z2);
        fz_free(ctx, val);
        val = val2;
      }
      /* Do NOT go down, we've already dealt with that. */
    }
    else if (fz_xml_is_tag(pos, "rPr") || fz_xml_is_tag(pos, "rPh"))
    {
      /* We do not want the 't' content from within these. */
    }
    else
    {
      /* Try to move down. */
      next = fz_xml_down(pos);
      if (next)
      {
        /* We can move down, easy! */
        pos = next;
        continue;
      }
    }
    /* Try moving to next. */
    next = fz_xml_next(pos);
    if (next)
    {
      /* We can move to next, easy! */
      pos = next;
      continue;
    }

    /* If we can't go down, or next, pop up until we
     * find somewhere we can go next from. */
    while (1)
    {
      /* OK. So move up. */
      pos = fz_xml_up(pos);
      /* Check for hitting the top. */
      if (pos == top)
        break;
      next = fz_xml_next(pos);
      if (next)
      {
        pos = next;
        break;
      }
    }
  }

  return val;
}

static fz_xml *
try_parse_xml_archive_entry(fz_context *ctx, fz_archive *arch, const char *filename, int preserve_white)
{
  if (!fz_has_archive_entry(ctx, arch, filename))
    return NULL;

  return fz_parse_xml_archive_entry(ctx, arch, filename, preserve_white);
}

static void
load_shared_strings(fz_context *ctx, fz_archive *arch, fz_xml *rels, doc_info *info, const char *file)
{
  fz_xml *pos = fz_xml_find_dfs(rels, "Relationship", "Type", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/sharedStrings");
  const char *ss_file = fz_xml_att(pos, "Target");
  char *resolved = NULL;
  fz_xml *xml = NULL;

  if (ss_file == NULL)
    return;

  fz_var(xml);
  fz_var(resolved);

  fz_try(ctx)
  {
    resolved = make_absolute_path(ctx, file, ss_file);
    xml = fz_parse_xml_archive_entry(ctx, arch, resolved, 1);

    pos = fz_xml_find_dfs(xml, "si", NULL, NULL);
    while (pos)
    {
      char **ss = fz_push_list(ctx, info->shared_strings);

      *ss = collate_t_content(ctx, pos);

      pos = fz_xml_find_next_dfs(pos, "si", NULL, NULL);
    }
  }
  fz_always(ctx)
  {
    fz_drop_xml(ctx, xml);
    fz_free(ctx, resolved);
  }
  fz_catch(ctx)
    fz_rethrow(ctx);
}

static void
load_footnotes(fz_context *ctx, fz_archive *arch, fz_xml *rels, doc_info *info, const char *file)
{
  char *resolved = NULL;
  fz_xml *xml = NULL;
  char *str = NULL;

  fz_var(xml);
  fz_var(str);
  fz_var(resolved);

  fz_try(ctx)
  {
    fz_xml *pos;

    resolved = make_absolute_path(ctx, file, "footnotes.xml");
    xml = try_parse_xml_archive_entry(ctx, arch, resolved, 1);
    if (xml == NULL)
      break;

    pos = fz_xml_find_dfs(xml, "footnote", NULL, NULL);
    while (pos)
    {
      int n = fz_atoi(fz_xml_att(pos, "w:id"));

      if (n < 0 || n >= INT_MAX)
      {
        fz_warn(ctx, "Footnote %d out of range", n);
      }
      else
      {
        str = collate_t_content(ctx, pos);
        if (str)
        {
          if (n >= info->footnotes_len)
            fz_extend_list(ctx, info->footnotes, n+1 - info->footnotes_len);

          info->footnotes[n] = str;
          str = NULL;
        }
      }
      pos = fz_xml_find_next_dfs(pos, "footnote", NULL, NULL);
    }
  }
  fz_always(ctx)
  {
    fz_drop_xml(ctx, xml);
    fz_free(ctx, resolved);
    fz_free(ctx, str);
  }
  fz_catch(ctx)
    fz_rethrow(ctx);
}

static void
process_office_document(fz_context *ctx, fz_archive *arch, const char *file, doc_info *info)
{
  char *file_rels;
  fz_xml *xml = NULL;
  fz_xml *rels = NULL;
  char *resolved_rel = NULL;

  if (file == NULL)
    return;

  file_rels = make_rel_name(ctx, file);

  fz_var(resolved_rel);

  fz_var(rels);
  fz_var(xml);

  fz_try(ctx)
  {
    fz_xml *pos;

    rels = fz_parse_xml_archive_entry(ctx, arch, file_rels, 0);
    xml = fz_parse_xml_archive_entry(ctx, arch, file, 1);

    /* XLSX */
    pos = fz_xml_find_dfs(xml, "sheet", NULL, NULL);
    if (pos)
    {
      load_shared_strings(ctx, arch, rels, info, file);
      while (pos)
      {
        char *name = fz_xml_att(pos, "name");
        char *id = fz_xml_att(pos, "r:id");
        char *sheet = lookup_rel(ctx, rels, id);

        if (sheet)
        {
          resolved_rel = make_absolute_path(ctx, file, sheet);
          process_sheet(ctx, arch, name, resolved_rel, info);
          fz_free(ctx, resolved_rel);
          resolved_rel = NULL;
        }
        pos = fz_xml_find_next_dfs(pos, "sheet", NULL, NULL);
      }
      break;
    }

    /* Let's try it as a powerpoint */
    pos = fz_xml_find_dfs(xml, "sldId", NULL, NULL);
    if (pos)
    {
      while (pos)
      {
        char *id = fz_xml_att(pos, "r:id");
        char *sheet = lookup_rel(ctx, rels, id);

        if (sheet)
        {
          resolved_rel = make_absolute_path(ctx, file, sheet);
          process_slide(ctx, arch, resolved_rel, info);
          fz_free(ctx, resolved_rel);
          resolved_rel = NULL;
        }
        pos = fz_xml_find_next_dfs(pos, "sldId", NULL, NULL);
      }
      break;
    }

    /* Let's try it as word. */
    {
      load_footnotes(ctx, arch, rels, info, file);
      process_doc_stream(ctx, xml, info, 1);
    }
  }
  fz_always(ctx)
  {
    fz_drop_xml(ctx, xml);
    fz_drop_xml(ctx, rels);
    fz_free(ctx, resolved_rel);
    fz_free(ctx, file_rels);
  }
  fz_catch(ctx)
    fz_rethrow(ctx);
}

static void
process_office_document_properties(fz_context *ctx, fz_archive *arch, const char *file, doc_info *info)
{
  fz_xml *xml = NULL;
  char *title;

  fz_var(xml);

  fz_try(ctx)
  {
    fz_xml *pos;

    xml = fz_parse_xml_archive_entry(ctx, arch, file, 1);

    pos = fz_xml_find_dfs(xml, "title", NULL, NULL);
    title = fz_xml_text(fz_xml_down(pos));
    if (title)
    {
      fz_write_string(ctx, info->out, "<title>");
      doc_escape(ctx, info->out, title);
      fz_write_string(ctx, info->out, "</title>");
    }
  }
  fz_always(ctx)
  {
    fz_drop_xml(ctx, xml);
  }
  fz_catch(ctx)
    fz_rethrow(ctx);
}

static fz_buffer *
fz_office_to_html(fz_context *ctx, fz_html_font_set *set, fz_buffer *buffer_in, fz_archive *dir, fz_office_to_html_opts *opts)
{
  fz_stream *stream = NULL;
  fz_archive *archive = NULL;
  fz_buffer *buffer_out = NULL;
  fz_xml *xml = NULL;
  fz_xml *pos = NULL;
  fz_xml *rels = NULL;
  const char *schema = "http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument";
  const char *schema_props = "http://schemas.openxmlformats.org/package/2006/relationships/metadata/core-properties";
  doc_info info = { 0 };
  int i;

  fz_var(archive);
  fz_var(stream);
  fz_var(buffer_out);
  fz_var(xml);
  fz_var(rels);

  if (opts)
    info.opts = *opts;

  fz_try(ctx)
  {
    if (buffer_in)
    {
      stream = fz_open_buffer(ctx, buffer_in);
      archive = fz_open_archive_with_stream(ctx, stream);
    }
    else
      archive = fz_keep_archive(ctx, dir);
    buffer_out = fz_new_buffer(ctx, 1024);
    info.out = fz_new_output_with_buffer(ctx, buffer_out);

    /* Is it an HWPX ?*/
    xml = try_parse_xml_archive_entry(ctx, archive, "META-INF/container.xml", 0);
    if (xml)
    {
      pos = fz_xml_find_dfs(xml, "rootfile", "media-type", "application/hwpml-package+xml");
      if (!pos)
        fz_throw(ctx, FZ_ERROR_FORMAT, "Archive not hwpx.");

      while (pos)
      {
        const char *file = fz_xml_att(pos, "full-path");
        process_rootfile(ctx, archive, file, &info);
        pos = fz_xml_find_next_dfs(pos, "rootfile", "media-type", "application/hwpml-package+xml");
      }
      fz_close_output(ctx, info.out);
      break;
    }

    /* Try other types */
    {
      xml = try_parse_xml_archive_entry(ctx, archive, "_rels/.rels", 0);

      fz_write_string(ctx, info.out, "<html>\n");

      pos = fz_xml_find_dfs(xml, "Relationship", "Type", schema_props);
      if (pos)
      {
        const char *file = fz_xml_att(pos, "Target");
        fz_write_string(ctx, info.out, "<head>\n");
        process_office_document_properties(ctx, archive, file, &info);
        fz_write_string(ctx, info.out, "</head>\n");
      }

      fz_write_string(ctx, info.out, "<body>\n");
      pos = fz_xml_find_dfs(xml, "Relationship", "Type", schema);
      if (!pos)
        fz_throw(ctx, FZ_ERROR_FORMAT, "Archive not docx.");

      while (pos)
      {
        const char *file = fz_xml_att(pos, "Target");
        if (file)
          process_office_document(ctx, archive, file, &info);
        pos = fz_xml_find_next_dfs(pos, "Relationship", "Type", schema);
      }
    }

    fz_close_output(ctx, info.out);
  }
  fz_always(ctx)
  {
    fz_drop_xml(ctx, rels);
    fz_drop_xml(ctx, xml);
    for (i = 0; i < info.shared_strings_len; ++i)
      fz_free(ctx, info.shared_strings[i]);
    fz_free(ctx, info.shared_strings);
    for (i = 0; i < info.footnotes_len; ++i)
      fz_free(ctx, info.footnotes[i]);
    fz_free(ctx, info.footnotes);
    fz_drop_output(ctx, info.out);
    fz_free(ctx, info.label);
    fz_drop_archive(ctx, archive);
    fz_drop_stream(ctx, stream);
  }
  fz_catch(ctx)
  {
    fz_drop_buffer(ctx, buffer_out);
    fz_rethrow(ctx);
  }

#ifdef DEBUG_OFFICE_TO_HTML
  {
    unsigned char *storage;
    size_t len = fz_buffer_storage(ctx, buffer_out, &storage);
    fz_write_printf(ctx, fz_stddbg(ctx), "fz_office_to_html: Output buffer, len=%zd:\n", len);
    fz_write_buffer(ctx, fz_stddbg(ctx), buffer_out);
  }
#endif

  return buffer_out;
}

/* Office document handler */

static fz_buffer *
office_to_html(fz_context *ctx, fz_html_font_set *set, fz_buffer *buf, fz_archive *zip)
{
  fz_office_to_html_opts opts = { 0 };

  return fz_office_to_html(ctx, set, buf, zip, &opts);
}

static const fz_htdoc_format fz_htdoc_office =
{
  "Office document",
  office_to_html,
  0, 1,
  FZ_HTML_FLAVOR_DEFAULT
};

static fz_document *
office_open_document(fz_context *ctx, const fz_document_handler *handler, fz_stream *file, fz_stream *accel, fz_archive *zip, void *state)
{
  return fz_htdoc_open_document_with_stream_and_dir(ctx, file, zip, &fz_htdoc_office);
}

static const char *office_extensions[] =
{
  "docx",
  "xlsx",
  "pptx",
  "hwpx",
  NULL
};

static const char *office_mimetypes[] =
{
  // DOCX
  "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
  // XLSX
  "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
  // PPTX
  "application/vnd.openxmlformats-officedocument.presentationml.presentation",
  // HWPX
  "application/haansofthwpx",
  "application/vnd.hancom.hwpx",
  NULL
};

/* We are only ever 75% sure here, to allow a 'better' handler, such as sodochandler
 * to override us by returning 100. */
static int
office_recognize_doc_content(fz_context *ctx, const fz_document_handler *handler, fz_stream *stream, fz_archive *zip, void **state, fz_document_recognize_state_free_fn **free_state)
{
  fz_archive *arch = NULL;
  int ret = 0;
  fz_xml *xml = NULL;

  if (state)
    *state = NULL;
  if (free_state)
    *free_state = NULL;

  fz_var(arch);
  fz_var(ret);
  fz_var(xml);

  fz_try(ctx)
  {
    if (stream)
    {
      arch = fz_try_open_archive_with_stream(ctx, stream);
      if (arch == NULL)
        break;
    }
    else
      arch = fz_keep_archive(ctx, zip);

    xml = fz_try_parse_xml_archive_entry(ctx, arch, "META-INF/container.xml", 0);
    if (xml)
    {
      if (fz_xml_find_dfs(xml, "rootfile", "media-type", "application/hwpml-package+xml"))
        ret = 75; /* HWPX */
      break;
    }
    xml = fz_try_parse_xml_archive_entry(ctx, arch, "_rels/.rels", 0);
    if (xml)
    {
      if (fz_xml_find_dfs(xml, "Relationship", "Type", "http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument"))
      {
        ret = 75; /* DOCX | PPTX | XLSX */
      }
      break;
    }
  }
  fz_always(ctx)
  {
    fz_drop_xml(ctx, xml);
    fz_drop_archive(ctx, arch);
  }
  fz_catch(ctx)
    fz_rethrow(ctx);

  return ret;
}

fz_document_handler office_document_handler =
{
  NULL,
  office_open_document,
  office_extensions,
  office_mimetypes,
  office_recognize_doc_content
};

Coverage Report

Created: 2026-11-12 07:07