??????? ? ?? ??????????
??????? XML-?????????
????????? XML-???????? ????? ???????? ?? ????????? ???????? (entities). ??? ???? ???????? ??????? ????????? ????? ???????? ????????, ??????? ?????????? ???????? ?????????, ???? ?? ????? ?????????? ?? ????????. ??? ??????? ????? ??????????; ??? ???, ????? ??????? ????????? ? ??????? DTD, ????? ???.
? ????? ?????? ??????????????? ??????? ????????? ??????? ?????????????? ?? ????????????? ? ???????????????. ??????????????? ?????? (unparsed entity)- ??? ??????, ?????????? ???????? XML-????????? ???????????? ??? ??????? ?????? ??? ?? ??????????????? ??????? (????????, ?????, ?? ?????????? XML-??????????). ??????????????? ??????? ?????? ????? ???????, ??????????? ?? ?? ??????. ????????????? ??????? (parsed entities) ????????????? ??? ????????? ???????????: ?????? ???, ????? XML-????????? ????????? ? ????????? ??? ?????? ???????, ?? ???????? ??? ?? ?????????? ????? ???????.
8.1.4.2. ?????????? ???????
?????????? ???????? ?????????????? ?? ?????????? ? ???????. ?????????? ??????????? ??????? ???????? ???:
<!ENTITY ??? ????????>
??? ???????? ? ???? ?????????? ??????? (???????? ????????) ? ???????????? ??? ??????????? ????? ???????? ?????? ????? ???????. ?? ?????, ????????, ?????? ? ?????? ? ??????? ??????? ???? ? ???????????? ??? ??????? ????? ?????????? ???????:
<!DOCTYPE spec [
<!ENTITY pr "?????">
<!ENTITY po "??????">
]>
<books>
<book genre="&po;">
<title>????? ????</title>
<author>????????, ?????</author>
</book>
<book genre="≺">
<title>???? ????????</title>
<author>????????, ??????</author>
</book>
</books>
?? ????? ??????? ?????, ??? ?????? ?? ?????? (entity reference) ???????? ????? ??? ??, ??? ?????? ?? ??????????? ??????, ?.?. ????? ??? &???;. ?? ????? ????, ??????????? ???????- ??? ????? ????? ?? ??????, ?? ??????????????? ??????? ?????? ?????? ?? ?????????? ?????????? ????? XML. ???????? ????????? ??????????? ?????? ??? ??????? ??????????, ??????????? ????????? ????? ?????????, ? ??? ???????? ??????????? ??? ????? ?????????? ????? ?????????. ???, ????????, ?? ????? ??????? ?? ?????????? ?????? ???? ????????? ??????? ?????????? ? ????? ???????? ?????? ???????? ????? ???????.
8.1.4.3. ??????? ???????
?????????? ??? ???????? ?????????? ???????? ???????:
<!ENTITY ??? SYSTEM URI [NDATA ???????]?>
<!ENTITY ??? PUBLIC ??????? URI [NDATA ???????]?>
?????? ??????? ?????????? ????????? ????????, ??????- ????????? ????????. ??? ??? ????????? ??? ??????? ? ??????? ????????, ???????? ????? URI, ??????? ?????? ????? ???????????? ????? ? ?? ????????? ????????.
URI (????. Uniform Resource Identifier) - ????????????? ????????????? ???????. ?? ?????????? ????? ???????????? ??? [?-??-???], ??-?????? ???? ??????? [????]. URI - ??? ???????? ?????????????????? ????????, ???????????????? ??????????? ??? ?????????? ??????. ????? ????????? Universal Resource Identifier - ????????????? ????????????? ???????.
URI ???????? ??????? ?????????? ????????? ??????????????? ???????. ????????????? ???????? ??????? ??????? ?? ?????????? ????????:
- ???? ?????????? ???????? ???????? NDATA, ???????? ??????? ???????, ?? ?????? ???????? ???????????????.
- ???? ???????? NDATA ?? ?????, ?? ?????? ?????????????, ? ??????????????? ?????? ?????? ???? XML-??????????. ??? ????????, ??? ?????? ?????? ?? ?????? ? ????? ????????? ????? ?????????? ????? ???????????????? ???????.
- ????????? ?????? ????? ????????? ??????, ???????? ????????? ????????????? ???????. XML-????????? ????? ???????????? ???? ????????????? ??? ????????? ??????????????? URI ??????? ???????. ???? ??? ??? ?? ???????, ?? ?? ?????? ???????????? ????????? ????????????? ??? ???????? ??????????? ???????.
??????? ?????????? ??????? ????????:
<!-- ??????????????? ??????: GIF-????? -->
<!ENTITY photo SYSTEM "images/photo.gif" NDATA gif>
<!-- ????????? ????????????? ?????? -->
<!ENTITY hatch SYSTEM "http://www.textuality.com/boilerplate/hatch.xml">
<!-- ????????? ????????????? ?????? -->
<!ENTITY hatch PUBLIC "-//Textuality//TEXT Standard hatch boilerplate//EN"
"http://www.textuality.com/boilerplate/hatch.xml">
??????? ????????????? ?????? ?????? ?????????? ? ????????? <?xml :?>, ??????? ????? ?? ????????? ?????? ??????, ?? ??????? ????????? ????????? ????????. ??? ????????? ?? ?????? ? ?????? ?????????????? ??????.