XML - XPath - Exemplu

Următoarele documente XML, scheme XSD și exemple de foi de stil XSL vă ajută să puneți împreună tot ce ați învățat în acest capitol folosind date din viața reală. Pe măsură ce studiați acest exemplu, veți observa cum XPath poate fi folosit în foaia de stil pentru a apela și modifica ieșirea unor informații specifice din document.

Mai jos este un document XML (Expunerea 9.4)


<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet href="movies.xsl" type="text/xsl" media="screen"?>
<movieCollection xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="movies.xsd">

<movie>
    <movieTitle>Meet the Parents</movieTitle>
    <movieSynopsis>
    Greg Focker is head over heels in love with his girlfriend Pam, and is ready to
    pop the big question. When his attempt to propose is thwarted by a phone call
    with the news that Pam's younger sister is getting married, Greg realizes that
    the key to Pam's hand in marriage lies with her formidable father.
    </movieSynopsis>
    <role>
        <roleIDREF>bs1</roleIDREF>
        <roleType>Lead Actor</roleType>
    </role>
    <role>
        <roleIDREF>tp1</roleIDREF>
        <roleType>Lead Actress</roleType>
    </role>
    <role>
        <roleIDREF>rd1</roleIDREF>
        <roleType>Lead Actor</roleType>
    </role>
    <role>
        <roleIDREF>bd1</roleIDREF>
        <roleType>Supporting Actress</roleType>
    </role>
</movie>

<movie>
    <movieTitle>Elf</movieTitle>
    <movieSynopsis>
    One Christmas Eve, a long time ago, a small baby at an orphanage crawled into
    Santa’s bag of toys, only to go undetected and accidentally carried back to Santa’s
    workshop in the North Pole. Though he was quickly taken under the wing of a surrogate
    father and raised to be an elf, as he grows to be three sizes larger than everyone else,
    it becomes clear that Buddy will never truly fit into the elf world. What he needs is
    to find his real family. This holiday season, Buddy decides to find his true place in the
    world and sets off for New York City to track down his roots.
    </movieSynopsis>
    <role>
        <roleIDREF>wf1</roleIDREF>
        <roleType>Lead Actor</roleType>
    </role>
    <role>
        <roleIDREF>jc1</roleIDREF>
        <roleType>Supporting Actor</roleType>
    </role>
    <role>
        <roleIDREF>zd1</roleIDREF>
        <roleType>Lead Actress</roleType>
    </role>
    <role>
        <roleIDREF>ms1</roleIDREF>
        <roleType>Supporting Actress</roleType>
    </role>
    </movie>

<castMember>
    <castMemberID>rd1</castMemberID>
    <castFirstName>Robert</castFirstName>
    <castLastName>De Niro</castLastName>
    <castSSN>489-32-5984</castSSN>
    <castGender>male</castGender>
</castMember>

<castMember>
    <castMemberID>bs1</castMemberID>
    <castFirstName>Ben</castFirstName>
    <castLastName>Stiller</castLastName>
    <castSSN>590-59-2774</castSSN>
    <castGender>male</castGender>
</castMember>

<castMember>
    <castMemberID>tp1</castMemberID>
    <castFirstName>Teri</castFirstName>
    <castLastName>Polo</castLastName>
    <castSSN>099-37-8765</castSSN>
    <castGender>female</castGender>
</castMember>

<castMember>
    <castMemberID>bd1</castMemberID>
    <castFirstName>Blythe</castFirstName>
    <castLastName>Danner</castLastName>
    <castSSN>273-44-8690</castSSN>
    <castGender>male</castGender>
</castMember>

<castMember>
    <castMemberID>wf1</castMemberID>
    <castFirstName>Will</castFirstName>
    <castLastName>Ferrell</castLastName>
    <castSSN>383-56-2095</castSSN>
    <castGender>male</castGender>
</castMember>

<castMember>
    <castMemberID>jc1</castMemberID>
    <castFirstName>James</castFirstName>
    <castLastName>Caan</castLastName>
    <castSSN>389-49-3029</castSSN>
    <castGender>male</castGender>
</castMember>

<castMember>
    <castMemberID>zd1</castMemberID>
    <castFirstName>Zooey</castFirstName>
    <castLastName>Deschanel</castLastName>
    <castSSN>309-49-4005</castSSN>
    <castGender>female</castGender>
</castMember>

<castMember>
    <castMemberID>ms1</castMemberID>
    <castFirstName>Mary</castFirstName>
    <castLastName>Steenburgen</castLastName>
    <castSSN>988-43-4950</castSSN>
    <castGender>female</castGender>
</castMember>

</movieCollection>

Expunerea 9.4: movies_xpath.xml

Mai jos este al doilea document XML (Expunerea 9.5)


<?xml version="1.0" encoding="UTF-8"?>

<cities xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="cities.xsd">

<city>
    <cityID>c2</cityID>
    <cityName>Mandal</cityName>
    <cityPopulation>13840</cityPopulation>
    <cityCountry>Norway</cityCountry>
    <tourismDescription>A small town with a big atmosphere.  Mandal provides comfort
away from normal luxuries.
    </tourismDescription>
    <capitalCity>c3</capitalCity>
</city>

<city>
    <cityID>c3</cityID>
    <cityName>Oslo</cityName>
    <cityPopulation>533050</cityPopulation>
    <cityCountry>Norway</cityCountry>
    <tourismDescription>Oslo is the capital of Norway for many reasons.
    It is also the capital location for tourism.  The culture, shopping,
    and attractions can all be experienced in Oslo.  Just remember
    to bring your wallet.
    </tourismDescription>
</city>

</cities>

Expunerea 9.5: cite__xpath.xml

Mai jos este schema Movies (Expunerea 9.6)


<?xml version="1.0" encoding="UTF-8"?>

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" elementFormDefault="unqualified">

  <!--Movie Collection-->

  <xsd:element name="movieCollection">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element name="movie" type="movieDetails" minOccurs="1" maxOccurs="unbounded"/>

      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>

  <!--This contains the movie details.-->

  <xsd:complexType name="movieDetails">
    <xsd:sequence>
      <xsd:element name="movieTitle" type="xsd:string" minOccurs="1" maxOccurs="unbounded"/>
      <xsd:element name="movieSynopsis" type="xsd:string"/>
      <xsd:element name="role" type="roleDetails" minOccurs="1" maxOccurs="unbounded"/>
    </xsd:sequence>
  </xsd:complexType>

 <!--The contains the genre details.-->

  <xsd:complexType name="roleDetails">
    <xsd:sequence>
       <xsd:element name="roleIDREF" type="xsd:IDREF"/>
       <xsd:element name="roleType" type="xsd:string"/>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:simpleType name="ssnType">
       <xsd:restriction base="xsd:string">
           <xsd:pattern value="\d{3}-\d{2}-\d{4}"/>
       </xsd:restriction>
   </xsd:simpleType>

 <xsd:complexType name="castDetails">
    <xsd:sequence>
       <xsd:element name="castMemberID" type="xsd:ID"/>
       <xsd:element name="castFirstName" type="xsd:string"/>
       <xsd:element name="castLastName" type="xsd:string"/>
       <xsd:element name="castSSN" type="ssnType"/>
       <xsd:element name="castGender" type="xsd:string"/>
    </xsd:sequence>
  </xsd:complexType>

</xsd:schema>

Expunerea 9.6: movies.xsd

Mai jos este schema Cities (Expunerea 9.7)


<?xml version="1.0" encoding="UTF-8"?>

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified"
attributeFormDefault="unqualified">

<xsd:element name="cities">
  <xsd:complexType>
    <xsd:sequence>
      <xsd:element name="city" type="cityType" maxOccurs="unbounded"/>
    </xsd:sequence>
  </xsd:complexType>
</xsd:element>
<xsd:complexType name="cityType">
  <xsd:sequence>
    <xsd:element name="cityID" type="xsd:ID"/>
     <xsd:element name="cityName" type="xsd:string"/>
     <xsd:element name="cityPopulation" type="xsd:integer"/>
     <xsd:element name="cityCountry" type="xsd:string"/>
     <xsd:element name="tourismDescription" type="xsd:string"/>
     <xsd:element name="capitalCity" type="xsd:IDREF" minOccurs="0" maxOccurs="1"/>
  </xsd:sequence>
</xsd:complexType>
</xsd:schema>

Expunerea 9.7: cities.xsd

Mai jos este foaia de stil XSL (Expunerea 9.8)


<?xml version="1.0" encoding="UTF-8"?>

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:key name="castList" match="castMember" use="castMemberID"/>
<xsl:output method="html"/>

<!-- example of using an abbreviated absolute path to pull info
from cities_xpath.xml for the city "Oslo" specifically -->

<!-- specify absolute path to select cityName and assign it the variable "city" -->
<xsl:variable name="city" select="document('cities_xpath.xml')
/cities/city[cityName='Oslo']/cityName" />

<!-- specify absolute path to select cityCountry and assign it the variable "country" -->
<xsl:variable name="country" select="document('cities_xpath.xml')
/cities/city[cityName='Oslo']/cityCountry" />

<!-- specify absolute path to select tourismDescription and assign it the variable "description" -->
<xsl:variable name="description" select="document('cities_xpath.xml')
/cities/city[cityName='Oslo']/tourismDescription" />

<xsl:template match="/">
<html>
    <head>
        <title>Movie Collection</title>
    </head>
    <body>
        <h2>Movie Collection</h2>
    <xsl:apply-templates select="movieCollection"/>
    </body>
</html>
</xsl:template>
<xsl:template match="movieCollection">

<!-- let's say we just want to see the actors. -->
<!--
<xsl:for-each select="movie">
<hr />
<br />
<b><xsl:text>Movie Title: </xsl:text></b>
<xsl:value-of select="movieTitle"/>
<br />
<br />
<b><xsl:text>Movie Synopsis: </xsl:text></b>
<xsl:value-of select="movieSynopsis"/>
<br />
<br />-->

<!-- actor info begins here. -->
<b><xsl:text>Cast: </xsl:text></b>
<br />
<!-- specify an abbreviated relative path here for "role."
NOTE: there is no predicate in this one; it's just a path. -->

<xsl:for-each select="movie/role">
<xsl:sort select="key('castList',roleIDREF)/castLastName"/>
<xsl:number value="position()" format="&#xa; 0. " />
<xsl:value-of select="key('castList',roleIDREF)/castFirstName"/>
<xsl:text>   </xsl:text>
<xsl:value-of select="key('castList',roleIDREF)/castLastName"/>
<xsl:text>,   </xsl:text>
<xsl:value-of select="roleType"/>
<br />
<xsl:value-of select="key('castList',roleIDREF)/castGender"/>
<xsl:text>,   </xsl:text>
<xsl:value-of select="key('castList',roleIDREF)/castSSN"/>
<br />
<br />
</xsl:for-each>
<!--
</xsl:for-each>-->
<hr />

<!--calling the variables -->

<span style="color:red;">
<p><b>Travel Advertisement</b></p>

<!-- reference the city, followed by a comma, and then the country -->
<p><xsl:value-of select="$city" />, <xsl:value-of select="$country" /></p>

<!-- reference the description -->
<xsl:value-of select="$description" />

</span>
</xsl:template>
</xsl:stylesheet>

Expunerea 9.6: movies.xsl

Rezumat

Acum ar trebui să înțelegeți bine relațiile dintre noduri prin utilizarea structurii arborelui XML. Folosirea conceptului de căi de locație Abreviate și Neabreviate ne permite să restrângem căutările noastre doar la un anumit element prin satisfacerea predicatului dintre paranteze pătrate. Relativ și Absolut sunt folosite pentru a spune calea către locația dvs. Calea Relativă oferă locația fișierului în raport cu directorul de lucru curent, în timp ce calea absolută oferă o locație exactă a unui fișier sau nume de director într-un computer sau sistem de fișiere. Ambele concepte pot fi combinate pentru a crea patru tipuri de căi de locație XPath: relativ abreviat, absolut abreviat, relativ neabreviat și, în sfârșit, absolut neabreviat. Dacă este necesară filtrarea suplimentară, pot fi utilizate predicate și funcții XPath. Acestea permit ca predicatul să fie evaluat pentru lucruri precum adevărat/fals și funcții de numărare. Când este utilizat corect, XPath poate fi un instrument foarte puternic în limbajul XML.

(Include texte din Wikibooks traduse și adaptate de Nicolae Sfetcu)