dtd读书笔记

Posted on 2006-07-12 20:06 daniel-shen 阅读(241) 评论(0) 收藏举报

定义文档结构。
如果DTD是包含在文档中，则需要定义，格式：
                    <!DOCTYPE root-element [element-declarations]>
                    eg:
                    <?xml version="1.0"?>
                    <!DOCTYPE note [---------------------------------------------------------------//说明这个文档是说明类型node的
                        <!ELEMENT note (to,from,heading,body)>----------------------------//说明node节点拥有4个子节点
                      <!ELEMENT to      (#PCDATA)>------------------------------------------//说明节点to的类型
                      <!ELEMENT from    (#PCDATA)>----------------------------------------//同上
                      <!ELEMENT heading (#PCDATA)>--------------------------------------//同上
                      <!ELEMENT body    (#PCDATA)>----------------------------------------//同上
                    ]>
         <note>
            <to>Tove</to>
            <from>Jani</from>
            <heading>Reminder</heading>
            <body>Don't forget me this weekend</body>
        </note>
如果DTD是在文件外部定义的：
在xml文件中声明：<!DOCTYPE note SYSTEM "note.dtd">指定文件note.dtd，文件内容为

                <!ELEMENT note (to,from,heading,body)>
                <!ELEMENT to (#PCDATA)>
                <!ELEMENT from (#PCDATA)>
                <!ELEMENT heading (#PCDATA)>
                <!ELEMENT body (#PCDATA)>
从dtd的观点看整个xml文件的结构，分为下面几个块


    Elements ------------------//节点
    
Attributes ----------------//属性
    
Entities ------------------//实体，如&lt(<),&gt(>),&amp(&),&quot(“),&apos(')
    
PCDATA --------------------//字符，将得到XML分析器的分析，同DHTML中的innerHTML
    
CDATA ---------------------//字符,不能得到XML分析器的分析，同DHTML中的innerText

Elements:
    声明一个节点：
                <!ELEMENT element-name category>
                or
                <!ELEMENT element-name (element-content)>
    空节点：<!ELEMENT br EMPTY>
    只含有字符数据的节点：<!ELEMENT from (#PCDATA)>
    拥有随意内容的节点：<!ELEMENT note ANY>
    拥有子节点的节点：<!ELEMENT note (to,from,heading,body)>
    定义只出现一次的子节点：<!ELEMENT note (message)>message 在note中只允许出现一次
    定义子节点至少出现一次：<!ELEMENT note (message+)>message 在note中至少出现一次
    定义子节点出现零次或多次：<!ELEMENT note (message*)>
    定义子节点出现0次或1次：<!ELEMENT note (message?)>
    定义出现的[或]关系：<!ELEMENT note (to,from,header,(message|body))>

    定义：<!ELEMENT note (#PCDATA|to|from|header|message)*>

Attributes:
    定义属性：<!ATTLIST element-name attribute-name attribute-type default-value>
              <!ATTLIST payment type CDATA "check">-------<payment type="check" />
attribute-type列表    

    
        
            Value Explanation
        
        
            
            CDATA
            
            
            The value is character data字符
            
        
        
            
            (en1|en2|..)
            
            
            The value must be one from an enumerated list枚举
            
        
        
            
            ID
            
            
            The value is a unique id 唯一，类似于主键
            
        
        
            
            IDREF
            
            
            The value is the id of another element类似于外键
            
        
        
            
            IDREFS
            
            
            The value is a list of other ids
            
        
        
            
            NMTOKEN
            
            
            The value is a valid XML name 一个合法的xml名字
            
        
        
            
            NMTOKENS
            
            
            The value is a list of valid XML names
            
        
        
            
            ENTITY
            
            
            The value is an entity 一个实体
            
        
        
            
            ENTITIES
            
            
            The value is a list of entities
            
        
        
            
            NOTATION
            
            
            The value is a name of a notation
            
        
        
            
            xml:
            
            
            The value is a predefined xml value

default-value列表：

Value	Explanation
value	The default value of the attribute
#REQUIRED	The attribute value must be included in the element 必须有此属性
#IMPLIED	The attribute does not have to be included 可有可无的属性，没有default value选项
#FIXED value	The attribute value is fixed 属性的固定值

        枚举属性值：<!ATTLIST element-name attribute-name (en1|en2|..) default-value>
                                eg:     dtd:    <!ATTLIST payment type (check|cash) "cash">
                                           xml:    <payment type="check" />
                                                        or
                                                     <payment type="cash" />
Entity:
            内部实体声明：
                语法:

        <!ENTITY entity-name "entity-value">
        DTD 例子:

        <!ENTITY writer "Donald Duck.">
        <!ENTITY copyright "Copyright W3Schools.">

        XML 例子:

        <author>&writer;&copyright;</author>

外部实体声明：

        语法:

        <!ENTITY entity-name SYSTEM "URI/URL">
        DTD 例子:

        <!ENTITY writer
        SYSTEM "http://www.w3schools.com/dtd/entities.dtd">
        <!ENTITY copyright
        SYSTEM "http://www.w3schools.com/dtd/entities.dtd">

        XML 例子:

        <author>&writer;&copyright;</author>
javascript验证xml文件是否合法，并输出错误信息：
    <html>
    <body>
    <h3>
    This demonstrates a parser error:
    </h3>

    <script type="text/javascript">
    var xmlDoc = new ActiveXObject("Microsoft.XMLDOM")
    xmlDoc.async="false"
    xmlDoc.validateOnParse="true"
    xmlDoc.load("note_dtd_error.xml")

    document.write("<br />Error Code: ")
    document.write(xmlDoc.parseError.errorCode)
    document.write("<br />Error Reason: ")
    document.write(xmlDoc.parseError.reason)
    document.write("<br />Error Line: ")
    document.write(xmlDoc.parseError.line)
    </script>

    </body>
    </html>
样例提供：（w3提供）
http://www.w3schools.com/dtd/dtd_examples.asp

刷新页面返回顶部

good things in life are free

公告

dtd读书笔记