XML简易教程之四

实业有五种预定义的xml实业，html源代码者应当熟悉。xml布告档案中的字符&、<、>、"和'被辩别表露为&、@lt;、>、"和'。xml很大程度上夸大了实业的工效 - 许诺在dtd中树立实业再不在布告档案的其余限制应用。比如，我在xml布告档案中需要常常应用短语"wired digital"，无妨在dtd中多么表露：<!entity wd "wired digital">多么当我应用这个短语时，无妨敲入&wd;。以是无妨遏止拼错和重复敲入勾通的动静。实业无妨起到字处治器中宏的功效。被代替的文本无妨大力长，但是纵然真是很长，大约要把动静生存在另一个文件中。无妨过程外部实业参考来举行 - 在实业名和文件的url中应用重要字system：<!entity text system "http://my.url.here">那些个性工效洪大，但有一个缺点：在一个dtd内不许被夸大。为了举行夸大工效，需要一个称为参数实业的特殊货色。它在实业树立中过程在实业名前插入"%"举行。一旦被树立，参数树立无妨过程用百分号和分号保护参数名来举行。干什么这么做？看看下面的代码：<!element vcard (%prop.man;, (%prop.id; | %prop.del; |%prop.tel; | %prop.geo; | %prop.org; |%prop.exp; | %prop.sec;)*)>这段代码来自一个公用的xml手刺草稿。当树立根元素时，作者创作更大略把动静辩别到各其余参数实业中。纵然看看其中的一个实业展示，我们就会领略干什么了。看看下面的prop.id实业：<!entity % prop.id "(nickname | photo | bday)">纵然每个实业都用这么长的字符串表露，元素树立将很难参观。现在无妨读一些dtd了。jay greenspan iso-8859-1 entities namedentity numericentity glyph description �- unused horizontaltab linefeed unused space ! ! exclamationmark " " " doublequotationmark # # numbersign $ $ dollarsign % % percentsign & & & amperstand ' ' apostrophe ( ( leftparenthesis ) ) rightparenthesis * * asterisk + + plussign , , comma - - hyphen . . period(fullstop) namedentity numericentity glyph description / / solidus(slash) 0-9 digits0-9 : : colon ; ; semicolon < < < less-thansign = = equalssign > > > greater-thansign ? ? questionmark @ @ commercialat a-z letters a-z [ ][ leftsquarebracket \ \ reversesolidus(backslash) ] ] rightsquarebracket ^ ^ caret _ _ horizontalbar(underscore) ` ` acuteaccent a-z letters a-z { { leftcurlybrace | | verticalbar namedentity numericentity glyph description } } rightcurlybrace ~ ~ tilde -Ÿ unused     non-breakingspace ¡ ¡ invertedexclamation ¢ ¢ centsign £ £ poundsterling ¤ ¤ generalcurrencysign ¥ ¥ yensign ¦ ¦ brokenverticalbar § § sectionsign ¨ ¨ umlaut(dieresis) © © © copyright ª ª feminineordinal « « leftanglequote, guillemotleft ¬ ¬ notsign ­ ­ softhyphen ® ® registeredtrademark ¯ ¯ macronaccent namedentity numericentity glyph description ° ° degreesign ± ± plusorminus ² ² superscripttwo ³ ³ superscriptthree ´ ´ acuteaccent µ µ microsign ¶ ¶ paragraphsign · · middledot ¸ ¸ cedilla ¹ ¹ superscriptone º º masculineordinal » » rightanglequote, guillemotright ¼ ¼ one-fourth ½ ½ one-half ¾ ¾ three-fourths ¿ ¿ invertedquestionmark À À À uppercasea, graveaccent Á Á Á uppercasea, acuteaccent    uppercasea, circumflexaccent namedentity numericentity glyph description à à à uppercasea, tilde Ä Ä Ä uppercasea, dieresisorumlautmark Å Å Å uppercasea, ring Æ Æ Æ uppercaseaedipthong(ligature) Ç Ç Ç uppercasec, cedilla È È È uppercasee, graveaccent É É É uppercasee, acuteaccent Ê Ê Ê uppercasee, circumflexaccent Ë Ë Ë uppercasee, dieresisorumlautmark Ì Ì Ì uppercasei, graveaccent Í Í Í uppercasei, acuteaccent Î Î Î uppercasei, circumflexaccent Ï Ï Ï uppercasei, dieresisorumlautmark Ð Ð Ð uppercaseeth, icelandic Ñ Ñ Ñ uppercasen, tilde Ò Ò Ò uppercaseo, graveaccent Ó Ó Ó uppercaseo, acuteaccent Ô Ô Ô uppercaseo, circumflexaccent Õ Õ Õ uppercaseo, tilde namedentity numericentity glyph description Ö Ö Ö uppercaseo, dieresisorumlautmark × × multiplysign Ø Ø Ø uppercaseo, slash Ù Ù Ù uppercaseu, graveaccent Ú Ú Ú uppercaseu, acuteaccent Û Û Û uppercaseu, circumflexaccent Ü Ü Ü uppercaseu, dieresisorumlautmark Ý Ý Ý uppercasey, acuteaccent Þ Þ Þ uppercasethorn, icelandic ß ß ß lowercasesharps, german(szligature) à à à lowercasea, graveaccent á á á lowercasea, acuteaccent â â â lowercasea, circumflexaccent ã ã ã lowercasea, tilde ä ä ä lowercasea, dieresisorumlautmark å å å lowercasea, ring æ æ æ lowercaseaedipthong(ligature) ç ç ç lowercasec, cedilla è è è lowercasee, graveaccent namedentity numericentity glyph description é é é lowercasee, acuteaccent ê ê ê lowercasee, circumflexaccent ë ë ë lowercasee, dieresisorumlautmark ì ì ì lowercasei, graveaccent í í í lowercasei, acuteaccent î î î lowercasei, circumflexaccent ï ï ï lowercasei, dieresisorumlautmark ð ð ð lowercaseeth, icelandic ñ ñ ñ lowercasen, tilde ò ò ò lowercaseo, graveaccent ó ó ó lowercaseo, acuteaccent ô ô ô lowercaseo, circumflexaccent õ õ õ lowercaseo, tilde ö ö ö lowercaseo, dieresisorumlautmark ÷ ÷ divisionsign ø ø ø lowercaseo, slash ù ù ù lowercaseu, graveaccent ú ú ú lowercaseu, acuteaccent û û û lowercaseu, circumflexaccent namedentity numericentity glyph description ü ü ü lowercaseu, dieresisorumlautmark ý ý ý lowercasey, acuteaccent þ þ þ lowercasethorn, icelandic ÿ ÿ ÿ lowercasey, dieresisorumlautmark