public void Write_body(Bry_bfr bfr, Xop_ctx ctx, Xoh_wtr_ctx hctx, Xoae_page page) {
   synchronized (thread_lock_2) {
     this.page = page;
     this.wiki = page.Wikie();
     this.app = wiki.Appe();
     Xoa_ttl page_ttl = page.Ttl();
     int page_ns_id = page_ttl.Ns().Id();
     byte page_tid =
         Xow_page_tid.Identify(
             wiki.Domain_tid(),
             page_ns_id,
             page_ttl
                 .Page_db()); // NOTE: can't cache page_tid b/c Write_body is called directly;
                              // DATE:2014-10-02
     byte[] data_raw = page.Db().Text().Text_bry();
     int bfr_page_bgn = bfr.Len();
     boolean page_tid_uses_pre = false;
     if (page_mode == Xopg_page_.Tid_edit) Write_body_edit(bfr, data_raw, page_ns_id, page_tid);
     else {
       switch (page_tid) {
         case Xow_page_tid.Tid_msg:
         case Xow_page_tid.Tid_js:
         case Xow_page_tid.Tid_css:
         case Xow_page_tid.Tid_lua:
           Write_body_pre(bfr, app, wiki, hctx, data_raw, tmp_bfr);
           page_tid_uses_pre = true;
           break;
         case Xow_page_tid.Tid_json:
           app.Wiki_mgr().Wdata_mgr().Write_json_as_html(bfr, page_ttl.Full_db(), data_raw);
           break;
         case Xow_page_tid.Tid_wikitext:
           Write_body_wikitext(bfr, app, wiki, data_raw, ctx, hctx, page, page_tid, page_ns_id);
           break;
       }
     }
     if (wiki.Domain_tid() != Xow_domain_tid_.Tid__home // allow home wiki to use javascript
         && !page_tid_uses_pre) { // if .js, .css or .lua, skip test; may have js fragments, but
                                  // entire text is escaped and put in pre; don't show spurious
                                  // warning; DATE:2013-11-21
       wiki.Html_mgr().Js_cleaner().Clean_bfr(wiki, page_ttl, bfr, bfr_page_bgn);
     }
   }
 }
	public static byte[] Write_wdata_links(List_adp slink_list, Xowe_wiki wiki, Xoa_ttl ttl, Wdata_external_lang_links_data external_links_mgr) {
		try {
			switch (wiki.Domain_tid()) {
				case Xow_domain_type_.Tid_home:		// home will never be in wikidata
				case Xow_domain_type_.Tid_wikidata:	// wikidata will never be in wikidata
					return Qid_null;
			}
			Wdata_wiki_mgr wdata_mgr = wiki.Appe().Wiki_mgr().Wdata_mgr();
			Wdata_doc doc = wdata_mgr.Pages_get(wiki, ttl); if (doc == null) return Qid_null;	// no links
			boolean external_links_mgr_enabled = external_links_mgr.Enabled();
			Ordered_hash links = doc.Slink_list();
			Bry_bfr tmp_bfr = wiki.Appe().Utl__bfr_mkr().Get_k004();
			Xow_wiki_abrv wiki_abrv = new Xow_wiki_abrv();
			int len = links.Count();
			for (int i = 0; i < len; i++) {
				Wdata_sitelink_itm slink = (Wdata_sitelink_itm)links.Get_at(i);
				byte[] xwiki_key = slink.Site();
				Xow_wiki_abrv_.parse_(wiki_abrv, xwiki_key, 0, xwiki_key.length);
				if (wiki_abrv.Domain_tid() == Xow_wiki_abrv_.Tid_null) {
					wiki.Appe().Usr_dlg().Warn_many("", "", "unknown wiki in wikidata: ttl=~{0} wiki=~{1}", ttl.Page_db_as_str(), String_.new_u8(xwiki_key));
					continue;
				}
				if (wiki_abrv.Domain_tid() != wiki.Domain_tid()) continue;	// ignore wikis in a different domain; EX: looking at enwiki:Earth, and wikidata has dewikiquote; ignore dewikiquote; DATE:2014-06-21
				byte[] lang_key = wiki_abrv.Lang_itm().Key();
				if (external_links_mgr_enabled && external_links_mgr.Langs_hide(lang_key, 0, lang_key.length)) continue;
				tmp_bfr.Add(lang_key);
				tmp_bfr.Add_byte(Byte_ascii.Colon);
				tmp_bfr.Add(slink.Name());
				Xoa_ttl slink_ttl = Xoa_ttl.parse_(wiki, tmp_bfr.Xto_bry_and_clear());
				if (slink_ttl == null) continue;								// invalid ttl
				Xow_xwiki_itm xwiki_itm = slink_ttl.Wik_itm();
				if (	xwiki_itm == null									// not a known xwiki; EX: [[zzz:abc]]
					||	Bry_.Eq(xwiki_itm.Domain_bry(), wiki.Domain_bry())	// skip if same as self; i.e.: do not include links to enwiki if already in enwiki
					) continue;
				slink.Page_ttl_(slink_ttl);
				slink_list.Add(slink);
			}
			tmp_bfr.Mkr_rls();
			if (external_links_mgr_enabled && external_links_mgr.Sort())
				slink_list.Sort_by(Xoa_ttl_sorter._);
			return doc.Qid();
		} catch (Exception e) {Err_.Noop(e); return Qid_null;}
	}
  private void Write_page_by_tid(
      Xop_ctx ctx,
      Xoh_wtr_ctx hctx,
      byte html_gen_tid,
      Bry_bfr bfr,
      Bry_fmtr fmtr,
      byte[] page_data) {
    // if custom_html, use it and exit; needed for Default_tab
    byte[] custom_html = page.Html_data().Custom_html();
    if (custom_html != null) {
      bfr.Add(custom_html);
      return;
    }
    // temp variables
    if (root_dir_bry == null) this.root_dir_bry = app.Fsys_mgr().Root_dir().To_http_file_bry();
    Xoa_ttl page_ttl = page.Ttl();
    int page_ns_id = page_ttl.Ns().Id();
    byte page_tid = Xow_page_tid.Identify(wiki.Domain_tid(), page_ns_id, page_ttl.Page_db());
    DateAdp modified_on = page.Db().Page().Modified_on();
    byte[] modified_on_msg =
        wiki.Msg_mgr()
            .Val_by_id_args(
                Xol_msg_itm_.Id_portal_lastmodified,
                modified_on.XtoStr_fmt_yyyy_MM_dd(),
                modified_on.XtoStr_fmt_HHmm());
    byte[] page_body_class = Xoh_page_body_cls.Calc(tmp_bfr, page_ttl, page_tid);
    byte[] html_content_editable =
        wiki.Gui_mgr().Cfg_browser().Content_editable() ? Content_editable_bry : Bry_.Empty;
    byte[] page_content_sub = Xoh_page_wtr_wkr_.Bld_page_content_sub(app, wiki, page, tmp_bfr);
    byte[] js_edit_toolbar_bry =
        html_gen_tid == Xopg_page_.Tid_edit
            ? wiki.Fragment_mgr().Html_js_edit_toolbar()
            : Bry_.Empty;
    Xol_vnt_mgr vnt_mgr = wiki.Lang().Vnt_mgr();
    if (vnt_mgr.Enabled()) {
      byte[] converted_title = vnt_mgr.Convert_lang().Converted_title(); // prefer converted title
      if (converted_title
          == null) // converted title does not exist; use regular page title and convert it
      converted_title = vnt_mgr.Convert_lang().Auto_convert(vnt_mgr.Cur_itm(), page_ttl.Page_txt());
      page_ttl = Xoa_ttl.Parse(wiki, page_ttl.Ns().Id(), converted_title);
    }
    byte[] page_name =
        Xoh_page_wtr_wkr_.Bld_page_name(
            tmp_bfr, page_ttl,
            null); // NOTE: page_name does not show display_title (<i>). always pass in null
    byte[] page_display_title =
        Xoh_page_wtr_wkr_.Bld_page_name(tmp_bfr, page_ttl, page.Html_data().Display_ttl());
    page.Html_data()
        .Custom_tab_name_(
            page_name); // set tab_name to page_name; note that if null, gui code will ignore and
                        // use Ttl.Page_txt; PAGE: zh.w:釣魚臺列嶼主權問題 DATE:2015-10-05
    Xow_portal_mgr portal_mgr = wiki.Html_mgr().Portal_mgr().Init_assert();
    fmtr.Bld_bfr_many(
        bfr,
        root_dir_bry,
        Xoa_app_.Version,
        Xoa_app_.Build_date,
        app.Tcp_server().Running_str(),
        page.Db().Page().Id(),
        page.Ttl().Full_db(),
        page_name,
        page.Html_data().Page_heading().Init(page.Html_data(), page_display_title),
        modified_on_msg,
        mgr.Css_common_bry(),
        mgr.Css_wiki_bry(),
        page.Html_data().Head_mgr().Init(app, wiki, page).Init_dflts(),
        page.Lang().Dir_ltr_bry(),
        page.Html_data().Indicators(),
        page_content_sub,
        wiki.Html_mgr().Portal_mgr().Div_jump_to(),
        wiki.Xtn_mgr().Xtn_pgbnr().Write_html(page, ctx, hctx),
        page_body_class,
        html_content_editable,
        page_data,
        wdata_lang_wtr

        // sidebar divs
        ,
        portal_mgr.Div_personal_bry(),
        portal_mgr.Div_ns_bry(wiki.Utl__bfr_mkr(), page_ttl, wiki.Ns_mgr()),
        portal_mgr.Div_view_bry(
            wiki.Utl__bfr_mkr(), html_gen_tid, page.Html_data().Xtn_search_text()),
        portal_mgr.Div_logo_bry(),
        portal_mgr.Div_home_bry(),
        new Xopg_xtn_skin_fmtr_arg(page, Xopg_xtn_skin_itm_tid.Tid_sidebar),
        portal_mgr.Div_sync_bry(
            tmp_bfr, app.Api_root().Addon().Bldr().Sync().Manual_enabled(), wiki, page),
        portal_mgr.Div_wikis_bry(wiki.Utl__bfr_mkr()),
        portal_mgr.Sidebar_mgr().Html_bry(),
        mgr.Edit_rename_div_bry(page_ttl),
        page.Html_data().Edit_preview_w_dbg(),
        js_edit_toolbar_bry);
    Xoh_page_wtr_wkr_.Bld_head_end(bfr, tmp_bfr, page); // add after </head>
    Xoh_page_wtr_wkr_.Bld_html_end(bfr, tmp_bfr, page); // add after </html>		
  }