xml.trx

(*
    Copyright © 2011 MLstate

    This file is part of OPA.

    OPA is free software: you can redistribute it and/or modify it under the
    terms of the GNU Affero General Public License, version 3, as published by
    the Free Software Foundation.

    OPA 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 OPA. If not, see <http://www.gnu.org/licenses/>.
*)
{{ open Parser_utils }}

(** importing from the lexer/main parser
 *  notice that deco in here is really careful_deco, so it doesn't parse spaces
 *)
let deco rule = (=Opa_parser.careful_deco(rule));
pos <- Opa_parser.pos;
read htmlentities.trx

#####################################################################################
## HTML TEXT ########################################################################
#####################################################################################

dquot              <- [\"]
squot              <- [\']

opa_expr           <- Opa_parser.opa_in_braces_nosp

htmlentity         <-
  / "&" Htmlentities.def:s ";"  {{ s }}
  / "&#" ([0-9]+ $_):s ";"           {{ Utf8.string_of_int (int_of_string s) }}
  / "&#x" (Opa_lexer.hexa:a {{ Char.hexa_value a }})+:l ";" {{ Utf8.string_of_int (List.fold_left (fun i acc -> acc * 16 + i) 0 l) }}
  / "\\" htmlspecial:s {{s}}

htmlspecial        <-
  / "{" {{ "{" }}
  / " " {{ "&nbsp;" }}
  / "<" {{ "&lt;" }}
  / ">" {{ "&gt;" }}
  / "&" {{ "&amp;" }}
  / "\\" {{ "\\" }}
  / pos:pos . {{
    error1 (Printf.sprintf "The char : %c is not a special char in xml." __2) pos
  }}

/** htmlchars **/
htmlchars          <-
  / htmlentity
  / ((![{] ![<] !htmlentity .)+  $_)

/** svaluechars **/
svaluechars        <-
  / htmlentity
  / ((![\'&] .)+ $_)

name                <- [a-zA-Z_0-9] [a-zA-Z_\-.0-9]*        $_
sname               <- name
ename               <- name
tname               <- name
#is the distinction really needed?
#sname              <- [a-zA-Z]+                         $_
#ename              <- [a-zA-Z0-9_\-]+                   $_
#tname              <- [a-zA-Z0-9]+                      $__

svalue             <- svaluechars*:s                    {{ String.concat "" s }}

namespace_aux          <- (sname:ns spacing [:] {{ ns }})?:o {{ Option.default "" o }}
namespace = deco namespace_aux

/** xml comment **/
comment            <- "<!--" (!"-->" .)* "-->"          $
spacing            <- Opa_lexer.spacing
spaces             <- Opa_lexer.spaces $_

htmltext           <- htmlchars+:s                      {{ concat_xml_text s }}

deco_sname         =  deco sname;
deco_ename         =  deco ename;
deco_tname         =  deco tname;
deco_htmltext      =  deco htmltext;
deco_svalue        =  deco svalue;
deco_spaces        =  deco spaces;
#####################################################################################
## TAGS FORMAT ######################################################################
#####################################################################################

open_sign          <- "<" spacing
close_sign         <- spacing ">"
autoclose          <- spacing "/" close_sign

begin_open_tag     <- open_sign namespace:ns deco_tname:tag spacing {{ push_tag (undecorate tag); (ns, tag) }}
(* FIXME: factorisation of open_tag and autoclose_tag *)
/** xml open tag **/
open_tag           <- begin_open_tag:nstag args_option:args close_sign   {{ (nstag, arg_default args) }}
/** xml close tag **/
close_tag          <- open_sign "/" spacing namespace:ns deco_tname:tag close_sign {{ ignore (pop_tag()); (ns, tag) }}

/** xml autoclose tag **/
autoclose_tag      <- begin_open_tag:nstag args_option:args autoclose    {{ ignore (pop_tag()); (nstag, arg_default args) }}

/** xml empty opening tag **/
open_frag          <- open_sign close_sign
/** xml empty closing tag **/
close_frag         <- open_sign "/" spacing close_sign

close_tag_or_frag <- close_tag:t {{ Some t }}
                   / close_frag {{ None }}

#####################################################################################
## XHTML TYPES ######################################################################
#####################################################################################
/** xml text **/
xhtml_text  <- deco_htmltext:v {{ create_textnode v }}

;xhtml_node <-
  / xhtml_tag / xhtml_text / xhtml_fragment
  / opa_expr:e {{ wrap_e magic_to_xml e }}

;/** xml tag **/
xhtml_tag <-
  / comment spacing xhtml_tag:tag {{ tag }}
  / autoclose_tag:t {{ let nstag,args = t in create_element nstag args [] }}
  / open_tag:open_tag just_xhtml_nodes:children close_tag_or_frag:close_tag
    {{ let nstag, args = open_tag in
         Option.iter (tag_mismatch nstag) close_tag;
         create_element nstag args children }}

;/** xml fragment **/
xhtml_fragment <- open_frag xhtml_nodes:p close_frag {{ let (l,label) = p in create_fragment l label }}
;xhtml_nodes = deco just_xhtml_nodes
;just_xhtml_nodes <- xhtml_node*


;xhtml_empty_frag = deco just_xhtml_empty_frag
;just_xhtml_empty_frag <- open_frag spacing close_frag

;xhtml_node_root    <-
   / xhtml_empty_frag:p                                                              {{ create_empty_fragment (label p) }}
   / (xhtml_tag / xhtml_fragment):t                                                  {{ t }}

;xhtml_node_root_with_spaces_plus = deco just_xhtml_node_root_with_spaces_plus
;just_xhtml_node_root_with_spaces_plus <- xhtml_node_root:v (deco_spaces:s xhtml_node_root:v
                                          {{ if fst s = "" then (None,v) else (Some s,v) }})*:l {{ (None,v) :: l }}
;unwrapped_xhtml             <- xhtml_node_root_with_spaces_plus:l             {{  create_fragment_with_spaces l  }}

#####################################################################################
## HTML ATTRIBUTES ##################################################################
#####################################################################################

#
# Some specific attributes need special handling to prevent agains XSS
#

;attr_name_with_special_handling <- (*style_insensitive {{ Some () }}
                                  /*) xhtml_specific tag_specific_a href_insensitive $

#Ensure that [style] is always typed
#Ensure that [a href] and [area href] are either static or checked dynamically

href_insensitive  <- "href"~

;args_option = deco just_args?;

/** xml attribute **/
just_args <-
  / "xmlns:" deco_ename:e spacing arg_attr:v spacing args_option:tl {{
       let old = arg_default tl in
       let c = (fst e,v) in
       {old with xmlns_declaration = c :: old.xmlns_declaration}
    }}
  / (=deco("xmlns")):xmlns spacing arg_attr:v spacing args_option:tl {{
       let old = arg_default tl in
       let c = ("",v) in
       {old with xmlns_declaration = c :: old.xmlns_declaration}
    }}
  / xhtml_specific style_insensitive spacing "=" spacing style_value:v spacing args_option:tl               {{ {(arg_default tl) with style  = Some v} }}
  / xhtml_specific class_insensitive spacing "=" spacing class_value:v spacing args_option:tl               {{ {(arg_default tl) with class_ = Some v} }}
  / xhtml_specific event_insensitive deco_sname:s spacing "=" spacing event_value:ev spacing args_option:tl {{ add_event tl s ev }}
  / xhtml_specific options_on_event_insensitive deco_sname:s spacing "=" spacing options_on_event_value:ev spacing args_option:tl  {{ add_event_option tl s ev }}
  / xhtml_specific "events" spacing "=" spacing opa_expr:e spacing args_option:tl                           {{ add_events tl e }}
  / xhtml_specific tag_specific_a href_insensitive spacing "=" spacing href_value:v spacing args_option:tl            {{ {(arg_default tl) with href = Some v } }}
  / !"xmlns" namespace:ns (!attr_name_with_special_handling) deco_ename:attr_n spacing arg_attr?:attr_v spacing args_option:tl           {{ add_arg tl (ns,attr_n) attr_v }}


arg_attr <- "=" spacing arg_value:v {{ v }}

/** xml attribute value **/
arg_value <-
  / squot deco_svalue:s squot {{ string2 s }}
  / String_expr.string_with_opa:e spacing {{ e }}
  / opa_expr:e {{ wrap_e magic_to_string e }}
  / deco_ename:s {{ string2 s }}
  / xhtml_specific Opa_parser.naked_id:v {{ v }}

(* handle the special case of [href] attribute, which could be used to inject scripts *)
href_value <-
   / squot deco_svalue:s squot     {{ record ["constant", string2 s] }}
   / opa_expr:e                    {{ record ["typed",    e] }}
   / String_expr.string_with_opa:e {{
     match e with
       | (Const (CString _), _)     -> record ["constant", e] (*This is a constant string, it needs no further checks*)
       | _                          -> record ["untyped", e]  (*This is a dynamic string, we need to perform whitelist filtering*)
   }}

#####################################################################################
## CSS INLINE ATTRIBUTES ############################################################
#####################################################################################

### See opa/opalib/lib/css.opa for the types used here
### Almost each rule correspond to one type defined there
### For concrete syntax examples, see opa/test/style.opa

style_insensitive  <- "style"~

style_sep          <- spacing ";" spacing
style_delim        <- spacing ":" spacing


css_size_units <- ("em"/"ex"/"px"/"in"/"cm"/"mm"/"pt"/"pc"/"%") $_

css_size_number_with_expr = deco just_css_size_number_with_expr;
just_css_size_number_with_expr <-
  / just_css_size_number_without_expr:v {{ v }}
  / opa_expr:v                     {{ `expr v }}

css_size_number_without_expr = deco just_css_size_number_without_expr;
just_css_size_number_without_expr <-
  / Opa_lexer.float:v {{ `float v }}
  / Opa_lexer.int:v   {{ `int v }}

css_size_with_or_without_expr <-
  / css_size_number_with_expr:e spacing css_size_units:u {{ (e, Some u) }}
  / css_size_number_without_expr:e spacing css_size_units?:u {{ (e, u) }}

css_size_value <- css_size_with_or_without_expr:e
 {{ let ((value,pos),unit) = e in
      match unit with
        | None ->
            if value = `float 0. || value = `int 0 then
              (* zero is the only value that is allowed not to have a unit *)
              record1 "em" (float 0. pos)
            else
              failwith "You have to give a unit for non-zero values in css lengths"
        | Some "px" ->
            record1 "px"
              ( match value with
                  | `int i -> int2 (i,pos)
                  | `float f -> intfloat2 (f,pos)
                  | `expr e -> e
              )
        | Some unit ->
            record1
              (match unit with "in" -> "inch" | "%" -> "percent" | unit -> unit)
              (match value with
                 | `int i -> floatint2 (i,pos)
                 | `float f -> float2 (f,pos)
                 | `expr e -> e
              )
  }}

css_size <-
  / css_size_value
  / opa_expr:e {{ coerce_name_expr e Opacapi.Types.Css.size }}

css_size_or_normal <-
  / (=deco("normal")):s {{ simple_record_expr "normal" (label s) }}
  / css_size_value:e {{ record1 "size" e }}
  / opa_expr:e {{ coerce_name_expr e Opacapi.Types.Css.size_or_normal }}

css_size_or_none <-
  / (=deco("none")):s {{ simple_record_expr "none" (label s) }}
  / css_size_value:e {{ record1 "size" e }}
  / opa_expr:e {{ coerce_name_expr e Opacapi.Types.Css.size_or_none }}

css_background_position_xy = deco just_css_background_position_xy;
just_css_background_position_xy <- css_size {{ `size __1 }}
                                 / "left" {{ `left }}
                                 / "center" {{`center }}
                                 / "right" {{ `right }}
                                 / "top" {{ `top }}
                                 / "bottom" {{ `bottom }}
css_background_position <-
  / css_background_position_xy:f css_background_position_xy?:s {{ background_position f s }}

css_repeat <-
  / (=deco( "repeat-x"
          / "repeat-y"
          / "no-repeat"
          / "repeat")):s
    {{ css_build (map_annot (fun s -> "background_"^hyphen_to_underscore s) s) [] }}

css_background_unary <-
  / opa_expr:e !css_size_units                                                        {{ coerce_name_expr e Opacapi.Types.Css.background }}
  (* this is the first rule because css_background_position can also start with an opa expr *)
  / Css.css_url:e                                                                     {{ css_build_unsafe "background_image" [e] }}
  / css_background_position:e                                                         {{ css_build_unsafe "background_position" [fst e; snd e] }}
  / css_repeat:e                                                                      {{ e }}
  / Css.color:e                                                                       {{ css_build_unsafe "background_color" [e] }}
  / (=deco("fixed")):p                                                                {{ css_build1' "background_attached" p }}

css_background <-
  / css_background_unary:v (spacing css_background_unary:v {{v}})*:l                  {{ list_expr_of_expr_list_unsafe (v :: l) }}

css_border_style_elt <-
  / (=deco("none"/"hidden"/"dotted"/"dashed"/"solid"/"double"/"groove"/"ridge"/"inset"/"outset")):v {{ css_build_with_prefix "border_" v }}

css_border_width_elt <-
  / (=deco("thin"/"medium"/"thick")):v {{ css_build_with_prefix "border_" v }}
  / css_size:e {{ css_build_unsafe "border_size" [e] }}

css_border_type <-
  / css_border_style_elt
  / css_border_width_elt
  / Css.color:e {{ css_build_unsafe "border_color" [e] }}

css_border_type_list <-
  / css_border_type:v (spacing css_border_type:v {{v}})*:l {{ css_build_unsafe "border_type" [list_expr_of_expr_list_unsafe (v :: l)] }}

css_default_cursor <-
  / (=deco("auto"/"crosshair"/"default"/"pointer"/"move"/"text"/"wait"/"progress"/"help")):v {{ css_build_with_prefix "cursor_" v }}
  / (=deco("e-resize"/"ne-resize"/"nw-resize"/"n-resize"/"se-resize"/"sw-resize"/"s-resize"/"w-resize")):v {{ let v' = map_annot (fun s -> fst (String.split_char '-' s)) v in
                                                                                                              css_build_with_prefix "cursor_resize_" v' }}
css_cursor <-
  / (Css.css_url:url spacing Opa_lexer.comma {{url}})*:l css_default_cursor:e {{ css_build_unsafe "cursor2" [list_expr_of_expr_list l (label e);e] }}

css_direction <-
  / (=deco("ltr")):p {{ simple_record_expr "right_to_left" (label p) }}
  / (=deco("rtl")):p {{ simple_record_expr "left_to_right" (label p) }}

css_display <-
  / (=deco("inline-block"/"none"/"block"/"inline")):v {{ css_simple_record_hyphen2 v }}

css_float <-
  / (=deco("none"/"left"/"right")):v {{ css_simple_record_hyphen2 v }}

#text_decoration <-
#  / (=deco("overline"/"underline"/"line-through"/"none")):v {{}}

css_decoration <-
  / (=deco("italic"/"bold"/"overline"/"underline"/"small-caps"/"line-through"/"normal")):v {{ css_simple_record_hyphen2 v }}

css_font_family <-
  / (=deco("TimesNewRoman"/"Georgia"/"Garamond"/"Helvetica"/"Verdana"/"Trebuchet"/"HeavyImpact"/"Monospace")):v {{ css_simple_record_hyphen2 v }}

css_font_variant <-
  / (=deco("normal" / "inherit" / "small-caps")):v {{ css_simple_record_hyphen2 v }}

css_decoration_list1 <-
  / css_decoration:v (spacing css_decoration:v {{v}})*:l {{ list_expr_of_expr_list_unsafe (v :: l) }}

#text_decoration_list1 <-
#  / text_decoration:v (spacing text_decoration:v {{v}})*:l {{ list_expr_of_expr_list_unsafe (v :: l) }}


css_font <-
  / css_decoration_list1?:dec pos:pos spacing css_size:size1 (spacing Opa_lexer.slash spacing css_size:size {{size}})?:size2 pos:pos2 spacing css_font_family:ff {{ css_build_unsafe "font2" [Option.default (list_nil pos) dec;size1;option_expr_of_expr_option size2 pos2; ff] }}

css_list_style_position <- (=deco("inside" / "outside")):v {{ css_simple_record_hyphen2 v }}
css_list_style_def <-
  / Css.css_url:v {{ record1 "image" v }}
  / (=deco(
       /"disc"/"square"
       /"decimal-leading-zero"
       /"decimal"
       /"lower-roman"
       /"upper-roman"
       /"lower-alpha"/"lower-latin"
       /"upper-alpha"/"upper-latin"
       /"lower-greek"
     )):v                            {{ list_style_def v }}

css_list_style <-
  / css_list_style_position:p (spacing css_list_style_def:d {{d}})?:d pos:pos {{ css_build_unsafe "list_style2" [some p; option_expr_of_expr_option d pos] }}
  / css_list_style_def:d (spacing css_list_style_position:p {{p}})?:p pos:pos {{ css_build_unsafe "list_style2" [option_expr_of_expr_option p pos; some d] }}

css_block_size <-
  / css_size (spacing css_size (spacing css_size (spacing css_size {{__2}})? {{ __2,__3 }})? {{ __2,__3 }})?
    {{ let a = __1 in
         match __2 with
           | None -> a, a, a, a (* top, left, bottom, right *)
           | Some (b, co) ->
               match co with
                 | None -> a, b, a, b
                 | Some (c, do_) ->
                     match do_ with
                       | None -> a, b, c, b
                       | Some d -> a, d, c, b
    }}

css_overflow <-
  (=deco("hidden"/"scroll"/"visible"/"auto")):v {{ simple_record_expr2 v }}

css_position <-
  (=deco("absolute"/"relative"/"fixed"/"static")):v {{ simple_record_expr2 v }}

css_align <-
  (=deco("left"/"right"/"center"/"justify")):v {{ simple_record_expr2 v }}

css_vertical_align <-
  (=deco("baseline" / "middle")):v {{ simple_record_expr2 v }}

css_visibility <-
  (=deco("visible" / "hidden")):v {{ simple_record_expr2 v }}

css_white_space <-
  (=deco("normal"/"pre"/"nowrap")):v {{ simple_record_expr2 v }}

css_z_index <-
  / (=deco("auto")):p {{ none (label p) }}
  / (=deco(Opa_lexer.int)):i {{ some (int2 i) }}

css_opacity <-
  (=deco(Opa_lexer.float)):v {{ float2 v }}

css_border_collapse <-
  (=deco("collapse" / "separate" / "inherit")):v {{ simple_record_expr2 v }}

css_table_layout <-
  (=deco("auto" / "fixed" / "inherit")):v {{ simple_record_expr2 v }}

css_unary <-
  / "background" style_delim css_background:v                                            {{ css_build_unsafe "background" [v] }}
  / "border-collapse" style_delim css_border_collapse:v                                  {{ css_build_unsafe "border_collapse" [v] }}
  / ("border-top"/"border-bottom"/"border-left"/"border-right"/"border"):s
      style_delim (css_border_type_list / opa_expr ):e                                   {{ let s =
                                                                                              match s with
                                                                                                | "border" -> "border_all"
                                                                                                   | s -> hyphen_to_underscore s
                                                                                            in
                                                                                              css_build_unsafe s [e] }}
    # FIXME lack of support for separate horizontal/vertical spacing; should be similar to
    #       block_size but with at most 2 (not 4) values
  / "border-spacing" style_delim css_size                                                {{ css_build_unsafe "border_spacing" [__3] }}
  / "border-radius" style_delim css_size                                                 {{ css_build_unsafe "border_radius" [__3] }}
  / "bottom" style_delim css_size                                                        {{ css_build_unsafe "bottom" [__3] }}
  / "color" style_delim (Css.color / opa_expr):v                                         {{ css_build_unsafe "color" [v] }}
  / "cursor" style_delim (css_cursor / opa_expr:e {{css_build_unsafe "cursor" [e]}})     {{ __3 }}
  / "direction" style_delim (css_direction / opa_expr)                                   {{ css_build_unsafe "direction" [__3] }}
  / "display" style_delim (css_display / opa_expr)                                       {{ css_build_unsafe "display" [__3] }}
  / "float" style_delim (css_float / opa_expr)                                           {{ css_build_unsafe "float" [__3] }}
  / "font" style_delim (css_font / opa_expr:e {{ css_build_unsafe "font" [e] }})         {{ __3 }}
  / "font-family" style_delim (css_font_family / opa_expr)                               {{ css_build_unsafe "font_family" [__3] }}
  / "font-size" style_delim css_size                                                     {{ css_build_unsafe "font_size" [__3] }}
  / "font-decoration" style_delim (css_decoration_list1 / opa_expr)                      {{ css_build_unsafe "font_decorations" [__3] }}
  / "font-variant" style_delim (css_font_variant / opa_expr)                             {{ css_build_unsafe "font_variant" [__3] }}
#  / "text-decoration" style_delim (text_decoration_list1 / opa_expr)                     {{ css_build_unsafe 
  / "height" style_delim css_size                                                        {{ css_build_unsafe "height" [__3] }}
  / ("min-height" / "max-height"):s style_delim css_size_or_none                         {{ css_build_unsafe (hyphen_to_underscore s) [__3] }}
  / "left" style_delim css_size                                                          {{ css_build_unsafe "left" [__3] }}
  / "letter-spacing" style_delim css_size_or_normal                                      {{ css_build_unsafe "letter_spacing" [__3] }}
  / "line-height" style_delim css_size                                                   {{ css_build_unsafe "line_height" [__3] }}
  / "list-style" style_delim (css_list_style / opa_expr:e {{ css_build_unsafe "list_style" [e]}}) {{ __3 }}
  / ("margin-top"/"margin-bottom"/"margin-left"/"margin-right") style_delim css_size     {{ css_build_unsafe (hyphen_to_underscore __1) [__3] }}
  / "margin" style_delim css_block_size                                                  {{ let (a,b,c,d) = map_tuple4 some __3 in
                                                                                              css_build_unsafe "margin" [a;b;c;d] }}
  / "opacity" style_delim css_opacity                                                    {{ css_build_unsafe "opacity" [__3] }}
  / "overflow" style_delim (css_overflow / opa_expr)                                     {{ css_build_unsafe "overflow" [__3] }}
  / ("padding-top"/"padding-bottom"/"padding-left"/"padding-right") style_delim css_size {{ css_build_unsafe (hyphen_to_underscore __1) [__3] }}
  / "padding" style_delim css_block_size                                                 {{ let (a,b,c,d) = map_tuple4 some __3 in
                                                                                              css_build_unsafe "padding" [a;b;c;d] }}
  / "position" style_delim (css_position / opa_expr)                                     {{ css_build_unsafe "position" [__3] }}
  / "right" style_delim css_size                                                         {{ css_build_unsafe "right" [__3] }}
  / "table-layout" style_delim css_table_layout                                          {{ css_build_unsafe "table_layout" [__3] }}
  / "text-align" style_delim (css_align / opa_expr)                                      {{ css_build_unsafe "text_align" [__3] }}
  / "top" style_delim css_size                                                           {{ css_build_unsafe "top" [__3] }}
  / "vertical-align" style_delim css_vertical_align                                      {{ css_build_unsafe "vertical_align" [__3] }}
  / "visibility" style_delim (css_visibility / opa_expr)                                 {{ css_build_unsafe "visibility" [__3] }}
  / "width":s style_delim css_size                                                       {{ css_build_unsafe "width" [__3] }}
  / ("min-width" / "max-width"):s style_delim css_size_or_none                           {{ css_build_unsafe (hyphen_to_underscore s) [__3] }}
  / "white-space" style_delim (css_white_space / opa_expr)                               {{ css_build_unsafe "white_space" [__3] }}
  / "z-index" style_delim (css_z_index / opa_expr)                                       {{ css_build_unsafe "z_index" [__3] }}

# Produces a typed CSS style, as a OPA [Css.property]
;css_properties <- (=deco(just_css_properties)):p {{ unc2 list_expr_of_expr_list p }}
just_css_properties <-
  / spacing css_unary:v spacing (style_sep spacing css_unary:v spacing {{ v }})*:l style_sep? spacing {{ v :: l }}

/** inlined css **/
style_value        <-
  / squot css_properties:e squot                                                       {{ e }}
  / dquot css_properties:e dquot                                                       {{ e }}
  / opa_expr:e                                                                         {{ e }}

#####################################################################################
## CLASS ATTRIBUTE ##################################################################
#####################################################################################

class_insensitive  <- "class"~

;class_attr = deco just_class_attr;
just_class_attr    <-
  / deco_sname:s spacing just_class_attr:l                                           {{ string2 s :: l  }}
  / deco_sname:s spacing                                                             {{ string2 s :: [] }}

/** xml class value **/
class_value        <-
  / squot class_attr:p squot                                                         {{ let (l,pos) = p in list_expr_of_expr_list (List.rev l) pos }}
  / dquot class_attr:p dquot                                                         {{ let (l,pos) = p in list_expr_of_expr_list (List.rev l) pos }}
  / deco_ename:e                                                                     {{ list_expr_of_expr_list [string2 e] (label e)}}
  / opa_expr:e                                                                       {{ e }}

#####################################################################################
## HANDLERS ASSIGNATION #############################################################
#####################################################################################

event_insensitive  <- "on"~

/** xml event value **/
event_value        <- opa_expr:e                                                       {{ action_xml e }}

options_on_event_insensitive <- "options:"event_insensitive
options_on_event_value <- opa_expr:e
                       / squot pos:pos spacing ((deco_ename:s spacing {{s}})*):l squot {{ list_constructors_of_string_list l pos }}
                       / dquot pos:pos spacing ((deco_ename:s spacing {{s}})*):l dquot {{ list_constructors_of_string_list l pos }}
                       / pos:pos                                                     {{ error1 "Incorrect use of options:event" pos }}

#####################################################################################
## MAIN RULE ########################################################################
#####################################################################################
(*; +xml*)
;
/** xhtml **/
xhtml <- enter_xhtml unwrapped_xhtml:v leave_xhtml {{ around_xhtml v }}
       / leave_xhtml {| None |}
/** xmlns **/
xmlns <- enter_xmlns unwrapped_xhtml:v leave_xmlns {{ around_xmlns v }}
       / leave_xmlns {| None |}

#####################################################################################
## NEEDED BY ANOTHER FILE ###########################################################
#####################################################################################

just_name_no_sp         <- [a-zA-Z0-9_\-]+                                                $_
;name_no_sp = deco just_name_no_sp;

#####################################################################################
# A FEW RULES TO DISTINGUISH XHTML AND XMLNS ########################################
#####################################################################################
enter_xhtml <- Opa_parser._succeed {{ push_xml Xhtml }}
enter_xmlns <- Opa_parser._succeed {{ push_xml Xml }}
leave_xhtml <- Opa_parser._succeed {{ pop_xml () }}
leave_xmlns <- Opa_parser._succeed {{ pop_xml () }}

xhtml_specific <- Opa_parser._succeed {| if xhtml_mode () then Some () else None |}
## special treatment for href attribute in <a> and <area> to avoid XSS
## not for <link> and <base> (only in header)
tag_specific_a <- Opa_parser._succeed {| match get_tag() with "a" | "area" -> Some () | _ -> None |}