%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2003-2016. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
%%% Description : Callback module for exporting XHTML to HTML.
-module(xmerl_html).
-export(['#xml-inheritance#'/0]).
%% Note: we assume XHTML data, so all tags are lowercase!
-export(['#root#'/4,
'#element#'/5,
'#text#'/1,
p/4]).
-import(xmerl_lib, [start_tag/2, end_tag/1, is_empty_data/1,
find_attribute/2, export_text/1]).
-include("xmerl.hrl").
'#xml-inheritance#'() -> [].
%% The '#text#' function is called for every text segment.
'#text#'(Text) ->
export_text(Text).
%% The '#root#' tag is called when the entire structure has been
%% exported. It does not appear in the structure itself.
'#root#'(Data, Attrs, [], _E) ->
Ver = case find_attribute(version, Attrs) of
{value, V} ->
V;
false ->
%%% "-//W3C//DTD HTML 4.01//EN" % strict
"-//W3C//DTD HTML 4.01 Transitional//EN" % loose
end,
URI = case find_attribute(uri, Attrs) of
{value, U} ->
[" \"", U, "\""];
false ->
%%% " \"http://www.w3.org/TR/html4/strict.dtd\""
%%% " \"http://www.w3.org/TR/html4/loose.dtd\""
""
end,
["<!DOCTYPE HTML PUBLIC \"", Ver, "\"", URI, ">\n", Data].
%% HTML does not have the <Tag/> empty-element form of XML/XHTML.
markup(Tag, Attrs, Data) ->
[start_tag(Tag, Attrs), Data, end_tag(Tag)].
%% Some HTML elements must not have an end tag at all.
markup_noend(Tag, Attrs, Data) ->
[start_tag(Tag, Attrs), Data].
%% For some element types, the end tag is forbidden. (In all other
%% cases, we always generate the end tag, to make sure that the scope of
%% a markup is not extended by mistake.)
'#element#'(Tag, Data, Attrs, _Parents, _E) ->
case forbid_end(Tag) of
false ->
markup(Tag, Attrs, Data);
true ->
markup_noend(Tag, Attrs, Data)
end.
%% HTML tags with special handling
p(Data, Attrs, _Parents, _E) ->
%% In general, we cannot drop the end tag for paragraph elements;
%% that is only allowed if we know that it is immediately followed
%% by some other block-level tag.
case is_empty_data(Data) of
true ->
%% Paragraph elements should never be completely empty.
markup(p, Attrs, "\s");
false ->
markup(p, Attrs, Data)
end.
%% Utility functions
forbid_end(area) -> true;
forbid_end(base) -> true;
forbid_end(basefont) -> true;
forbid_end(br) -> true;
forbid_end(col) -> true;
forbid_end(frame) -> true;
forbid_end(hr) -> true;
forbid_end(img) -> true;
forbid_end(input) -> true;
forbid_end(isindex) -> true;
forbid_end(link) -> true;
forbid_end(meta) -> true;
forbid_end(param) -> true;
forbid_end(_) -> false.
