Generate XML Elements

If you use RootElement() Start the root element of the document , Is responsible for generating each element in the root element . There are three options ：

Generate objects as elements

It can be downloaded from InterSystems IRIS Object generates output as an element . In this case , Use object() Method , This method supports writing XML The object of . The output includes all object references contained in the object . You can specify the name of this element , You can also use the default values defined in the object .

Only in RootElement() and EndRootElement() Use between methods object() Method .

This example is enabled for a given XML All saved instances of the class of generate output ：

/// desc： Output the data in the table to the local file 
/// w ##class(PHA.TEST.Xml).WriteAll("Sample.Person")
ClassMethod WriteTableAllToXml(cls As %String = "", directory As %String = "E:\temp\")
{
    if '##class(%Dictionary.CompiledClass).%ExistsId(cls) {
        Write !, " Class does not exist or is not compiled "
        Quit 
    }
    s check=$classmethod(cls, "%Extends", "%XML.Adaptor")
    If 'check {
        Write !, " Class does not extend %XML.Adaptor"
        Quit 
    }
        
    s filename = directory_"Person"_".xml"
    
    s writer = ##class(%XML.Writer).%New()
    s writer.Indent=1
    s status = writer.OutputToFile(filename)
    if $$$ISERR(status) { do $System.Status.DisplayError(status) quit  }
    
    s status=writer.RootElement("SampleOutput")
    if $$$ISERR(status) { do $System.Status.DisplayError(status) quit  }

    // Get the ID
    s stmt = ##class(%SQL.Statement).%New()
    s status = stmt.%PrepareClassQuery(cls,"Extent")
    if $$$ISERR(status) { do $System.Status.DisplayError(status) quit  }
    
    s rset = stmt.%Execute()
    while (rset.%Next()) {
        // For each ID, Write this object 
        set objid = rset.%Get("ID")
        set obj = $CLASSMETHOD(cls,"%OpenId",objid)
        set status = writer.Object(obj)
        if $$$ISERR(status) {Do $System.Status.DisplayError(status) Quit}}
        
    d writer.EndRootElement()
    d writer.EndDocument()
    q ""
}

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The output of this method contains all the saved objects of the given class , These objects are nested in the root element . about Sample.Person, Output is as follows ：

<?xml version="1.0" encoding="UTF-8"?>
<SampleOutput>
  <Person>
    <Name>Tillem,Robert Y.</Name>
    <SSN>967-54-9687</SSN>
    <DOB>1961-11-27</DOB>
    <Home>
      <Street>3355 First Court</Street>
      <City>Reston</City>
      <State>WY</State>
      <Zip>11090</Zip>
    </Home>
    <Office>
      <Street>4922 Main Drive</Street>
      <City>Newton</City>
      <State>NM</State>
      <Zip>98073</Zip>
    </Office>
    <FavoriteColors>
      <FavoriteColorsItem>Red</FavoriteColorsItem>
    </FavoriteColors>
    <Age>47</Age>
  </Person>
  <Person>
    <Name>Waters,Ed X.</Name>
    <SSN>361-66-2801</SSN>
    <DOB>1957-05-29</DOB>
    <Home>
      <Street>5947 Madison Drive</Street>
...
</SampleOutput>

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Build elements manually

Constructed manually XML Elements . In this case , Use element() Method , This method writes the start tag of the element with the supplied name . then , You can write content 、 Attributes and child elements . Use EndElement() Method indicates the end of the element .

The relevant methods are as follows ：

Element()

method Element(tag, namespace As %String) as %Status

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Write start tag . You can provide namespaces for elements , Only when XML There is no class for Namespace The namespace is applied only when the value of the parameter .

WriteAttribute()

method WriteAttribute(name As %String, 
                      value As %String  = "", 
                      namespace As %String, 
                      valueNamespace As %String  = "", 
                      global As %Boolean  = 0) as %Status

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Write properties . Attribute name and value must be specified . The parameter namespace is the namespace of the attribute name . Parameters valueNamespace Is the namespace of the attribute value ; On duty XML When defined in the schema namespace .

about GLOBAL, If the attribute is in the associated XML Architecture is global , So there should be a prefix , Please specify TRUE.

If you use this method , Must be in Element()( or RootElement()) Then use it directly .

WriteChars()

method WriteChars(text) as %Status

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Write string , Perform any necessary escape required to make the string fit as element content . Parameter must %String Type or %CharacterStream type .

WriteCData()

method WriteCData(text) as %Status

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Parameter must %String Type or %CharacterStream type .

WriteBase64()

method WriteBase64(binary) as %Status

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Encode the specified binary bytes as base-64, And write the result text into the content of the element . The parameter must be of type %Binary or %BinaryStream.

WriteBinHex()

method WriteBinHex(binary) as %Status

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Encode the specified binary bytes into binary , And write the result text into the content of the element . The parameter must be of type %Binary or %BinaryStream.

EndElement()

method EndElement() as %Status

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End the element that can match it .

Only in RootElement() and EndRootElement() Use these methods between methods .

Be careful ： The method described here is intended to enable to XML Document specific logical fragments , But in some cases , More control may be required .%XML.Writer Class provides an additional method write(), You can use this method to write any string . Responsible for ensuring that the results are well formed XML file ; No verification is provided .

Example

Here is an example routine ：

/// w ##class(Demo.XmlDemo).WriteObjXml()
ClassMethod WriteObjXml()
{
 
    set writer=##class(%XML.Writer).%New()
    set writer.Indent=1

    set status=writer.OutputToDevice()
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.StartDocument()
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.RootElement("root")
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.Element("SampleElement")
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.WriteAttribute("Attribute","12345")
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.Element("subelement")
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.WriteChars("yao")
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.EndElement()
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.Element("subelement")
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.WriteChars("xin")
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.EndElement()
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.EndElement()
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.EndRootElement()
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}

    set status=writer.EndDocument()
    if $$$ISERR(status) {do $System.Status.DisplayError(status) quit}
    q ""
}

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DHC-APP>w ##class(Demo.XmlDemo).WriteObjXml()
<?xml version="1.0" encoding="UTF-8"?>
<root>
  <SampleElement Attribute="12345">
    <subelement>yao</subelement>
    <subelement>xin</subelement>
  </SampleElement>
</root>

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Use %XMLL.Element

In the previous section , We used Element() And specify the elements to be generated ; We can also specify namespaces . In some cases , Class %XML.Element Example , Instead of using element names . This class has the following properties ：

• Local Property specifies whether this element is a local element of its parent element , This will affect the control of namespaces .
• Namespace Attribute specifies the namespace of this element .
• Tagname Attribute specifies the name of this element .

You can also use the above described WriteAttribute() Method .