Developing ColdFusion MX Applications with CFML
Using XML and WDDX

Using an XML object

Because an XML document object is represented as a structure, you can access XML document contents using either, or a combination of both, of the following ways:

• Using the element names, such as mydoc.employee.name[1]
• Using the corresponding structure entry names (that is, XmlChildren array entries), such as mydoc.employee.XmlChildren[1]

Similarly, you can use either, or a combination of both, of the following notation methods:

• Structure (dot) notation, such as mydoc.employee
• Associative array (bracket) notation, such as mydoc["employee"]

Referencing the contents of an XML object

Use the following rules when you reference the contents of an XML document object on the right side of an assignment or as a function argument:

• By default, ColdFusion ignores element name case. As a result, it considers the element name MyElement and the element name myELement to be equivalent. To make element name matching case-sensitive, specify CaseSensitive="True" in the cfxml tag, or specify True as a second argument in the XMLNew or XMLParse function that creates the document object.
• Use an array index to specify one of multiple elements with the same name; for example, #mydoc.employee.name[1] and #mydoc.employee.name[2].

  If you omit the array index on the last component of an element identifier, ColdFusion treats the reference as the array of all elements with the specified name. For example, mydoc.employee.name refers to an array of two name elements.

• Use an array index into the XmlChildren array to specify an element without using its name; for example, mydoc.XmlRoot.XmlChildren[1].
• Use associative array (bracket) notation to specify an element name that contains a period or colon; for example, myotherdoc.XmlRoot["Type1.Case1"].
• You can use DOM methods in place of structure entry names.

For example, the following variables all refer to the XmlText value "Almanzo" in the XML document created in "A simple XML document":

mydoc.XmlRoot.XmlChildren[1].XmlChildren[1].XmlText

mydoc.employee.name[1].first.XmlText
mydoc.employee.name[1]["first"].XmlText
mydoc["employee"].name[1]["first"].XmlText
mydoc.XmlRoot.name[1].XmlChildren[1]["XmlText"]

The following variables all refer to the EmpType attribute of the first name element in the XML document created in "A simple XML document" :

mydoc.employee.name[1].XmlAttributes.EmpType

mydoc.employee.name[1].XmlAttributes["EmpType"]
mydoc.employee.XmlChildren[1].EmpType
mydoc.XmlRoot.name[1].XmlAttributes["EmpType"]
mydoc.XmlRoot.XmlChildren[1].EmpType

Neither of these lists contains a complete set of the possible combinations that can make up a reference to the value or attribute.

Assigning data to an XML object

When you use an XML object reference on the left side of an expression, the preceding rules apply to the reference up to the last element in the reference string.

For example, the rules in "Referencing the contents of an XML object" apply to mydoc.employee.name[1].first in the following expression:

mydoc.employee.name[1].first.MyNewElement = XmlElemNew(mydoc, NewElement);

The following rules apply to the meaning of the last component on the left side of an expression:

• The component name is an element structure key name (XML property name), such as XmlComment, ColdFusion sets the value of the specified element structure entry to the value of the right side of the expression. For example, the following line sets the XML comment in the mydoc.employee.name[1].first element to "This is a comment":

  mydoc.employee.name[1].first.XmlComment = "This is a comment";
  

• If the component name specifies an element name and does not end with a numeric index, for example mydoc.employee.name, ColdFusion assigns the value on the right of the expression to the first matching element.

  For example, if both mydoc.employee.name[1] and mydoc.employee.name[2] exist, the following expression replaces mydoc.employee.name[1] with a new element named address, not an element named name:

  mydoc.employee.name = XmlElemNew(mydoc, "address");
  

  After executing this line, if there had been both mydoc.employee.name[1] and mydoc.employee.name[2], there is now only one mydoc.employee.name element with the contents of the original mydoc.employee.name[2].

• If the component name does not match an existing element, the element names on the left and right sides of the expression must match. ColdFusion creates a new element with the name of the element on the left of the expression. If the element names do not match, it generates an error.

  For example if there is no mydoc.employee.name.phoneNumber element, the following expression creates a new mydoc.employee.name.phoneNumber element:

  mydoc.employee.name.phoneNumber = XmlElemNew(mydoc, "phoneNumber");
  

  The following expression causes an error:

  mydoc.employee.name.phoneNumber = XmlElemNew(mydoc, "address");
  

• If the component name does not match an existing element and the component's parent or parents also do not exist, ColdFusion creates any parent nodes as specified on the left side and use the previous rule for the last element. For example, if there is no mydoc.employee.phoneNumber element, the following expression creates a phoneNumber element containing an AreaCode element:

  mydoc.employee.name.phoneNumber.AreaCode = XmlElemNew(mydoc, "AreaCode");
  

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