CSC 2720 Building Web Applications

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CSC 2720Building Web Applications

• Flex
• ECMAScript for XML (E4X)

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ECMAScript for XML (E4X)

• A programming language extension that adds native
  XML support to ECMAScript
• Treats XML as a primitive type (instead of as an
  object)

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public var employeesXML
ltemployeesgt ltemployee
ssn"123-123-1234"gt ltname
first"John" last"Doe"/gt
ltaddressgt ltstreetgt11
Main St.lt/streetgt
ltcitygtSan Franciscolt/citygt
ltstategtCAlt/stategt
ltzipgt98765lt/zipgt
lt/addressgt lt/employeegt
ltemployee ssn"789-789-7890"gt
ltname first"Mary" last"Roe"/gt
ltaddressgt
ltstreetgt99 Broad St.lt/streetgt
ltcitygtNewtonlt/citygt
ltstategtMAlt/stategt
ltzipgt01234lt/zipgt
lt/addressgt lt/employeegt
lt/employeesgt
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public var employeesXML
ltemployeesgt ltemployee
ssn"123-123-1234"gt ltname
first"John" last"Doe"/gt
ltaddressgt ltstreetgt11
Main St.lt/streetgt
ltcitygtSan Franciscolt/citygt
ltstategtCAlt/stategt
ltzipgt98765lt/zipgt
lt/addressgt lt/employeegt
ltemployee ssn"789-789-7890"gt
ltname first"Mary" last"Roe"/gt
ltaddressgt
ltstreetgt99 Broad St.lt/streetgt
ltcitygtNewtonlt/citygt
ltstategtMAlt/stategt
ltzipgt01234lt/zipgt
lt/addressgt lt/employeegt
lt/employeesgt

• employees.employee0.address.zip
• or
• employees.employee0.address'zip'
• 1st employee element ? all address elements ? all
  zip elements of each address element

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public var employeesXML
ltemployeesgt ltemployee
ssn"123-123-1234"gt ltname
first"John" last"Doe"/gt
ltaddressgt ltstreetgt11
Main St.lt/streetgt
ltcitygtSan Franciscolt/citygt
ltstategtCAlt/stategt
ltzipgt98765lt/zipgt
lt/addressgt lt/employeegt
ltemployee ssn"789-789-7890"gt
ltname first"Mary" last"Roe"/gt
ltaddressgt
ltstreetgt99 Broad St.lt/streetgt
ltcitygtNewtonlt/citygt
ltstategtMAlt/stategt
ltzipgt01234lt/zipgt
lt/addressgt lt/employeegt
lt/employeesgt

• employees.employee1._at_ssn
• or
• employees.employee1._at_'ssn'
• 2nd employee element ? attribute ssn

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public var employeesXML
ltemployeesgt ltemployee
ssn"123-123-1234"gt ltname
first"John" last"Doe"/gt
ltaddressgt ltstreetgt11
Main St.lt/streetgt
ltcitygtSan Franciscolt/citygt
ltstategtCAlt/stategt
ltzipgt98765lt/zipgt
lt/addressgt lt/employeegt
ltemployee ssn"789-789-7890"gt
ltname first"Mary" last"Roe"/gt
ltaddressgt
ltstreetgt99 Broad St.lt/streetgt
ltcitygtNewtonlt/citygt
ltstategtMAlt/stategt
ltzipgt01234lt/zipgt
lt/addressgt lt/employeegt
lt/employeesgt

• employees.employee.name
• All employee elements ? all name elements of each
  employee element

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public var employeesXML
ltemployeesgt ltemployee
ssn"123-123-1234"gt ltname
first"John" last"Doe"/gt
ltaddressgt ltstreetgt11
Main St.lt/streetgt
ltcitygtSan Franciscolt/citygt
ltstategtCAlt/stategt
ltzipgt98765lt/zipgt
lt/addressgt lt/employeegt
ltemployee ssn"789-789-7890"gt
ltname first"Mary" last"Roe"/gt
ltaddressgt
ltstreetgt99 Broad St.lt/streetgt
ltcitygtNewtonlt/citygt
ltstategtMAlt/stategt
ltzipgt01234lt/zipgt
lt/addressgt lt/employeegt
lt/employeesgt

• employees..zip0
• Root element ? first zip element that is a
  descendent

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public var employeesXML
ltemployeesgt ltemployee
ssn"123-123-1234"gt ltname
first"John" last"Doe"/gt
ltaddressgt ltstreetgt11
Main St.lt/streetgt
ltcitygtSan Franciscolt/citygt
ltstategtCAlt/stategt
ltzipgt98765lt/zipgt
lt/addressgt lt/employeegt
ltemployee ssn"789-789-7890"gt
ltname first"Mary" last"Roe"/gt
ltaddressgt
ltstreetgt99 Broad St.lt/streetgt
ltcitygtNewtonlt/citygt
ltstategtMAlt/stategt
ltzipgt01234lt/zipgt
lt/addressgt lt/employeegt
lt/employeesgt

• employees.._at_ssn1
• Root element ? 2nd ssn attribute among the
  descendents

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public var employeesXML
ltemployeesgt ltemployee
ssn"123-123-1234"gt ltname
first"John" last"Doe"/gt
ltaddressgt ltstreetgt11
Main St.lt/streetgt
ltcitygtSan Franciscolt/citygt
ltstategtCAlt/stategt
ltzipgt98765lt/zipgt
lt/addressgt lt/employeegt
ltemployee ssn"789-789-7890"gt
ltname first"Mary" last"Roe"/gt
ltaddressgt
ltstreetgt99 Broad St.lt/streetgt
ltcitygtNewtonlt/citygt
ltstategtMAlt/stategt
ltzipgt01234lt/zipgt
lt/addressgt lt/employeegt
lt/employeesgt

• employees.employee0.address.
• 1st employee element ? all address elements ? all
  immediate child elements

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public var employeesXML
ltemployeesgt ltemployee
ssn"123-123-1234"gt ltname
first"John" last"Doe"/gt
ltaddressgt ltstreetgt11
Main St.lt/streetgt
ltcitygtSan Franciscolt/citygt
ltstategtCAlt/stategt
ltzipgt98765lt/zipgt
lt/addressgt lt/employeegt
ltemployee ssn"789-789-7890"gt
ltname first"Mary" last"Roe"/gt
ltaddressgt
ltstreetgt99 Broad St.lt/streetgt
ltcitygtNewtonlt/citygt
ltstategtMAlt/stategt
ltzipgt01234lt/zipgt
lt/addressgt lt/employeegt
lt/employeesgt

• var sString ''
• for each (var numXML in employees.._at_ssn)
• s (num) " "
• // s becomes "123-123-1234 789-789-7890 "

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public var employeesXML
ltemployeesgt ltemployee
ssn"123-123-1234"gt ltname
first"John" last"Doe"/gt
ltaddressgt ltstreetgt11
Main St.lt/streetgt
ltcitygtSan Franciscolt/citygt
ltstategtCAlt/stategt
ltzipgt98765lt/zipgt
lt/addressgt lt/employeegt
ltemployee ssn"789-789-7890"gt
ltname first"Mary" last"Roe"/gt
ltaddressgt
ltstreetgt99 Broad St.lt/streetgt
ltcitygtNewtonlt/citygt
ltstategtMAlt/stategt
ltzipgt01234lt/zipgt
lt/addressgt lt/employeegt
lt/employeesgt

• var ssnToFindString "789-789-7890"
• employees.employee.(_at_ssn ssnToFind).toXMLStrin
  g()
• Select all employee elements ? Retain only those
  with attribute ssn equals to "789-789-7890" ? Get
  the XML representation of the selected elements

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References and Resources

• ActionScript 3.0 Language and Components
  Reference XML
• http//livedocs.adobe.com/flash/9.0/ActionScriptLa
  ngRefV3/XML.html
• ActionScript 3.0 library for several basic
  utilities
• http//code.google.com/p/as3corelib/