| Microsoft XML Core Services (MSXML) 4.0 - SOM Developer's Guide |  |
| Microsoft XML Core Services (MSXML) 4.0 - SOM Developer's Guide | |
This topic walks you through the Walk the SOM application. The code is interspersed with textual comments that describe each step of the application.
Click here for the Uncommented Code for the Walk the SOM Application.
The code begins with some constant declarations.
' Item types: SOMITEM_SCHEMA = 4*1024 SOMITEM_ATTRIBUTE = SOMITEM_SCHEMA + 1 SOMITEM_ATTRIBUTEGROUP = SOMITEM_SCHEMA + 2 SOMITEM_NOTATION = SOMITEM_SCHEMA + 3 SOMITEM_ANYTYPE = 8*1024 SOMITEM_DATATYPE = SOMITEM_ANYTYPE+256 SOMITEM_SIMPLETYPE = SOMITEM_DATATYPE+256 SOMITEM_COMPLEXTYPE = 9*1024 SOMITEM_PARTICLE = 16*1024 SOMITEM_ANY = SOMITEM_PARTICLE+1 SOMITEM_ANYATTRIBUTE = SOMITEM_PARTICLE+2 SOMITEM_ELEMENT = SOMITEM_PARTICLE+3 SOMITEM_GROUP = SOMITEM_PARTICLE+256 SOMITEM_ALL = SOMITEM_GROUP+1 SOMITEM_CHOICE = SOMITEM_GROUP+2 SOMITEM_SEQUENCE = SOMITEM_GROUP+3 SOMITEM_EMPTYPARTICLE = SOMITEM_GROUP+4 ' Attribute uses SCHEMAUSE_OPTIONAL = 0 SCHEMAUSE_PROHIBITED = 1 SCHEMAUSE_REQUIRED = 2 SCHEMACONTENTTYPE_EMPTY = 0 SCHEMACONTENTTYPE_TEXTONLY = 1 SCHEMACONTENTTYPE_ELEMENTONLY = 2 SCHEMACONTENTTYPE_MIXED = 3
The remarks variable is used to turn on the display of remarks in the result text. Set to 1 so that remarks will be shown.
remarks = 1
Create a schema cache object. This object will be used later to contain the XML Schema document, po.xsd.
Set oSchemaCache = CreateObject("Msxml2.XMLSchemaCache.4.0")
Set oAnnotationDoc = CreateObject("Msxml2.DOMDocument.4.0")
nsTarget="http://www.example.microsoft.com/po"
Add the XML Schema document to the schema cache, using its add method. A SOM schema object is returned. The SOM interfaces will now be used to explore the schema object.
For more information about the schema cache, see the IXMLDOMSchemaCollection add and get methods.
oSchemaCache.add nsTarget, "po.xsd" Set oSchema = oSchemaCache.getSchema(nsTarget)
result = "<xsd:schema xmlns:xsd='http://www.w3.org/2001/XMLSchema'>"+ vbNewLine
Use the elements collection, from the schema object, to explore the information in the individual elements.
For Each oE in oSchema.elements
result = result + printElement(oE, 0)
Next
For Each oA in oSchema.attributes
result = result + printAttr(oA, t)
Next
result = result + vbNewLine
Use the collection of type objects (ISchemaType interface) to explore each type declaration from the schema object.
For Each oT in oSchema.types
result = result + processType(oT, 0)
Next
result = result + "</xsd:schema>"
WScript.Echo result
' ---------------------------------------------------------------------
Create a function to examine the itemType property of the type object passed to it. This function will send the type object to the appropriate function for examining the properties of the passed object.
Function processType(oType, t)
If oType.itemType = SOMITEM_ANYTYPE Then
res = res + printTab(t+1) + "<!-- " + oType.name +" -->"
End If
If oType.itemType = SOMITEM_COMPLEXTYPE then
res = res + processComplexType(oType, t+1)
End If
If oType.itemType = SOMITEM_SIMPLETYPE then
res = res + processSimpleType(oType, t+1)
End If
processType = res + vbNewLine
End Function
' ---------------------------------------------------------------------
Create a function to walk through the properties of a complexType object that is passed to it.
Function processComplexType(oComplex, t)
res = printTab(t) + "<xsd:complexType"
Check to see if a name attribute was declared in the type declaration.
If oComplex.name <> "" Then
res = res + " name='" + oComplex.name +"'"
End If
res = res + ">"
Check the contentType property to decide how to process the four possible choices of content type.
If oComplex.contentType = SCHEMACONTENTTYPE_EMPTY Then res = res + printRemark("emtpy") End If If oComplex.contentType = SCHEMACONTENTTYPE_TEXTONLY Then res = res + printRemark("textonly") End If
Because the type might contain other elements, send the content model to the processGroup function that will walk through the contentModel properties.
If oComplex.contentType =SCHEMACONTENTTYPE_ELEMENTONLY Then res = res + printRemark("elementonly ") res = res + processGroup(oComplex.contentModel, t+1) End If If oComplex.contentType = SCHEMACONTENTTYPE_MIXED Then res=res+ "<!-- mixed -->"+vbNewLine res = res + processGroup(oComplex.contentModel, t+1) End If res = res + vbNewline If oComplex.baseTypes.length > 0 Then res = res + printRestrictions(oComplex, t+1) End If On Error Resume Next
Set any = oComplex.anyAttribute.name If Err.number = 0 Then res = res + oComplex.anyAttribute.name End If
Walk through each attribute declaration in the complex type. The attribute objects that are used are returned from the attributes property of the ISchemaType object.
For Each oAttr in oComplex.attributes res = res + printAttr(oAttr, t+1) Next processComplexType = res + printTab(t) + "</xsd:complexType>"+vbNewline End Function ' ---------------------------------------------------------------------
Create a function to walk through a simpleType object (ISchemaType) interface and get its properties.
Function processSimpleType(oSimple, t)
res = printTab(t) + "<xsd:simpleType"
If oSimple.name <> "" Then
res = res + " name='" + oSimple.name +"'"
End If
res = res + ">"+vbNewline
Call a function to walk through the restrictions of the simple type that is passed to it.
If oSimple.baseTypes.length = 1 Then
There is only one base type. Therefore, send the type object to the function.
res = res + printRestrictions(oSimple, t+1)
Else
There are multiple base types. Therefore, send each type in the baseTypes collection to a function that will extract its name property.
For Each oType in oSimple.baseTypes res = res + "<baseType name='" + printName(oType) +"'>"+vbNewline Next End If processSimpleType = res + printTab(t) + "</xsd:simpleType>"+vbNewline End Function ' ---------------------------------------------------------------------
Function processGroup(poGroup, t) res = "" If poGroup.itemType = SOMITEM_ALL then res = res + printTab(t+1) + "<xsd:all>"+vbNewline res = res + processChoiceOrSequence(poGroup, t+1) res = res + printTab(t+1) + "</xsd:all>" End If If poGroup.itemType = SOMITEM_CHOICE then res = res + printTab(t+1) + "<xsd:choice>"+vbNewline res = res + processChoiceOrSequence(poGroup, t+1) res = res + printTab(t+1) + "</xsd:choice>" End If If poGroup.itemType = SOMITEM_SEQUENCE then res = res + printTab(t+1) + "<xsd:sequence>"+vbNewline res = res + processChoiceOrSequence(poGroup, t+1) res = res + printTab(t+1) + "</xsd:sequence>" End If processGroup = res End Function ' ---------------------------------------------------------------------
Create a function to examine the itemType property of the modelGroup object. The function will then send each item from the particles collection to the appropriate function for examining the properties of the item.
Function processChoiceOrSequence(poGroup, t)
res = ""
For Each item in poGroup.particles If item.itemType = SOMITEM_ELEMENT then res = res + printElement(item, t+1) End If If (item.itemType and SOMITEM_GROUP) = SOMITEM_GROUP then res = res + processGroup(item, t+1)+vbNewline End If If item.itemType = SOMITEM_ANY then res = res + "any: " + item.name+vbNewline End If Next processChoiceOrSequence = res End Function ' ---------------------------------------------------------------------
Create a function to walk through the properties of an element object.
Function printElement(oElement, t)
res = printTab(t) + "<xsd:element "
Check the isReference property of the element object to see if the element is a reference to a top-level element declaration.
If oElement.isReference Then
res = res + "ref='" + oElement.name + "'" + printParticles(oElement) + ">"
res = res + "<!-- "
Check the isAbstract property of the element object to see if the element has had its abstract attribute set to true or to false.
res = res + " abstract='" & oElement.isAbstract & "'"
res = res + " -->"
Else
Get the type information for the element in a type object returned from the type property of the element object.
Set oType=oElement.type
Send the element object to a function that will extract its particle information from the inherited minOccurs and maxOccurs properties of the element object.
res = res + "name='" + oElement.name + "'" + printParticles(oElement)
res = res + " abstract='" & oElement.isAbstract & "'"
res = res + " id='" & oElement.id & "'" If oType.name = "" Then res = res + ">" + vbNewLine
Check the itemType enumerated value of the type object to see what interface is needed to extract type information for the element's type.
If oType.itemType = SOMITEM_COMPLEXTYPE Then
res = res + printElement + processComplexType(oType, t+1)
Else
res = res + processSimpleType(oType, t)
End If
res = res + printTab(t) + "</xsd:element>"
The type has been declared as a separate type declaration. The name property of the type object is not equal to "".
Else
If printName(oType) <> "xsd:anyType" Then
res = res + " type='" + printName(oType) + "'"
End If
If oType.itemType <> SOMITEM_COMPLEXTYPE Then
If oType.baseTypes.length = 0 Then
res = res + "/>"
Else
res = res + ">" + vbNewLine + processSimpleType(oType, t)
res = res + printTab(t) + "</xsd:element>"
End If
Else
res = res + "/>"
End If
End If
End If
Use the scope property of the element object to find out the name of the scope used in the element declaration.
If Not oElement.scope Is Nothing Then strRem = "scope:" + printName(oElement.scope) End If res = res + printRemark( "rem" ) printElement = res End Function ' ---------------------------------------------------------------------
Create a function to get the particle information from the object that is passed in.
Function printParticles(oParticle)
If oParticle.minOccurs <> 1 Then res = res + " minOccurs='" & oParticle.minOccurs & "'" End If
If oParticle.maxOccurs <> 1 Then If oParticle.maxOccurs = -1 Then res = res + " maxOccurs='unbounded'" Else res = res + " maxOccurs='" & oParticle.maxOccurs & "'" End If End If printParticles = res End Function ' ---------------------------------------------------------------------
Create a function to walk through the properties of an attribute object.
Function printAttr(oAttr, t)
Check the isReference property of the attribute object to see if the attribute is a reference to a top-level element declaration
If oAttr.isReference Then printAttr = printAttr + printTab(t) + "<xsd:attribute ref='" + oAttr.name + "'" Else printAttr = printAttr + printTab(t) + "<xsd:attribute name='" + oAttr.name + "'" End If
Check to see whether the type used for the attribute is declared in the attribute declaration, or declared separately. The code performs this check by looking at the name property of the type property for the attribute object.
If oAttr.type.name <> "" Then printAttr = printAttr + " type='" + printName(oAttr.type) + "'" End If
Check the defaultValue property of the attribute object to see if the defaultValue attribute was defined in the declaration of the attribute.
If oAttr.defaultValue <> "" Then printAttr = printAttr + " default='" + oAttr.defaultValue + "'" End If
Check the fixedValue property of the attribute object to see if the fixedValue attribute was defined in the declaration of the attribute.
If oAttr.fixedValue <> "" Then
printAttr = printAttr + " fixed='" + oAttr.fixedValue + "'"
End If
Check the use property of the attribute object to see the restrictions placed on the entry of the attribute into an XML Schema instance document.
If oAttr.use = SCHEMAUSE_OPTIONAL Then printAttr = printAttr + " use='optional'" End If If oAttr.use = SCHEMAUSE_PROHIBITED Then printAttr = printAttr + " use='prohibited'" End If If oAttr.use = SCHEMAUSE_REQUIRED Then printAttr = printAttr + " use='required'" End If printAttr = printAttr + "/>"
If Not oAttr.scope Is Nothing Then strRem = "scope:" + printName(oAttr.scope) End If printAttr = printAttr + printRemark(strRem) End Function ' ---------------------------------------------------------------------
This function is used to format the output information in a tab structure. No SOM functionality is included in this function.
Function printTab(t)
tab=""
For x=0 to t
tab=tab+" "
Next
printTab=tab
End Function
' ---------------------------------------------------------------------
Create a function to check the type property of an item and get the name of the item. The function uses the name property to return the name. The name property is inherited from the ISchemaItem interface.
Function printName(item)
printName =""
If (item.itemType and SOMITEM_DATATYPE) = SOMITEM_DATATYPE Then printName= "xsd:" End If If item.itemType = SOMITEM_ANYTYPE Then printName= "xsd:" End If
printName= printName + item.name End Function ' ---------------------------------------------------------------------
Create a function to get the restriction information from the type object or the complexType object that is passed to it. Each restriction that returns a string is checked for a NULL value. If the value is not NULL, the restriction value is retrieved from the appropriate property. Each restriction that returns an integer is checked for a value of "–1". This value indicates that the restriction is not used. If the value is greater than "–1", the restriction value is retrieved for the appropriate property. All other restrictions used in this function have comments listed below.
Function printRestrictions(oType, t)
res = ""
If oType.minExclusive <> "" Then res = res + printTab(t+1) + "<xsd:minExclusive value='"+ oType.minExclusive + "'/>" + vbNewLine End If
If oType.minInclusive <> "" Then res = res + printTab(t+1) + "<xsd:minInclusive value='"+ oType.minInclusive + "'/>" + vbNewLine End If
If oType.maxExclusive <> "" Then res = res + printTab(t+1) + "<xsd:maxExclusive value='"+ oType.maxExclusive + "'/>" + vbNewLine End If
If oType.maxInclusive <> "" Then res = res + printTab(t+1) + "<xsd:maxInclusive value='"+ oType.maxInclusive + "'/>" + vbNewLine End If
If oType.totalDigits > -1 Then res = res + printTab(t+1) + "<xsd:totalDigits value='" & oType.totalDigits & "'/>" + vbNewLine End If
If oType.fractionDigits > -1 Then res = res + printTab(t+1) + "<xsd:fractionDigits value='" & oType.fractionDigits & "'/>" + vbNewLine End If
If oType.length > -1 Then res = res + printTab(t+1) + "<xsd:length value='" & oType.length & "'/>" + vbNewLine End If
If oType.minLength > -1 Then res = res + printTab(t+1) + "<xsd:minLength value='" & oType.minLength & "'/>" + vbNewLine End If
If oType.maxLength > -1 Then res = res + printTab(t+1) + "<xsd:maxLength value='" & oType.maxLength & "'/>" + vbNewLine End If
Check the length of the enumeration property. If the length is greater than zero, get the value of the enumeration from the collection of enumerations.
If oType.enumeration.length > 0 Then
For Each item in oType.enumeration res = res + printTab(t+1) + "<xsd:enumeration value='" + item + "'/>" + vbNewLine Next End If
Check the value of the whitespace property. If the value is greater than zero, get the whitespace value of the type object.
If oType.whitespace > 0 Then res = res + printTab(t+1) + "<xsd:whitespace value='" & oType.whitespace & "'/>" + vbNewLine End If If oType.patterns.length <> 0 Then
For Each oPattern in oType.patterns res = res + printTab(t+1) + "<xsd:pattern value='" + oPattern + "'/>" + vbNewLine Next End If printRestrictions = "" If res <> "" and oType.baseTypes.length > 0 Then printRestrictions = printRestrictions + printTab(t) + "<xsd:restriction base='" + printName(oType.baseTypes(0)) + "'>" + vbNewLine printRestrictions = printRestrictions + res printRestrictions = printRestrictions + printTab(t) + "</xsd:restriction>" + vbNewLine End If End Function ' ---------------------------------------------------------------------
This function wraps the value that is passed in the parameter in remark tags.
No SOM functionality is included in this function.
Function printRemark(r)
If remarks = 1 Then
printRemark = "<!-- " + r + " -->"
End If
printRemark = printRemark + vbNewLine
End Function
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