/// <summary>
/// Create an abstract description of an element in a collection of filters, sorts and transforms.
/// </summary>
/// <param name="propertySchema">A description of the property.</param>
/// <param name="xmlNode">The XML Schema extensions that describe the query.</param>
public QuerySchema(PropertySchema propertySchema, XmlNode xmlNode)
{
// Initialize the object.
this.propertySchema = propertySchema;
// Extract the name of the query. This will default to an randomly generated name of not explicitly stated in the
// schema.
XmlAttribute nameAttribute = xmlNode.Attributes[QualifiedName.VariableName.Name, QualifiedName.VariableName.Namespace];
this.name = nameAttribute == null?RandomVariableName.NewName() : nameAttribute.Value;
// Extract the resulting type. This will default to the property type if not explicitly stated in the schema.
XmlAttribute resultTypeAttribute = xmlNode.Attributes[QualifiedName.ResultType.Name, QualifiedName.ResultType.Namespace];
this.resultType = resultTypeAttribute == null ? String.Empty : resultTypeAttribute.Value;
// Extract the source of data for the query. This will default to the result of the previous query if not explicitly
// stated in the schema.
XmlAttribute sourceAttribute = xmlNode.Attributes[QualifiedName.Source.Name, QualifiedName.Source.Namespace];
this.source = sourceAttribute == null ? String.Empty : sourceAttribute.Value;
// Extract the type of the source data. This will default to the type of the source of data for this query if not
// explicitly stated in the schema.
XmlAttribute sourceTypeAttribute = xmlNode.Attributes[QualifiedName.SourceType.Name, QualifiedName.SourceType.Namespace];
this.sourceType = sourceTypeAttribute == null ? String.Empty : sourceTypeAttribute.Value;
}
/// <summary>
/// Creates a description of a LINQ clause that selectively removes items from a data source.
/// </summary>
/// <param name="propertySchema">A description of the property.</param>
/// <param name="xmlNode">The XML Schema extensions that describe the query.</param>
public WhereSchema(PropertySchema propertySchema, XmlNode xmlNode)
: base(propertySchema, xmlNode)
{
// Extract the name of the predicate (the method that selectively qualifies records) from the XML Schema extension.
XmlAttribute predicateAttribute = xmlNode.Attributes[QualifiedName.Predicate.Name, QualifiedName.Predicate.Namespace];
this.predicate = predicateAttribute.Value;
}
/// <summary>
/// Create an abstract description of an operation that selects one object from another.
/// </summary>
/// <param name="propertySchema">A description of the property.</param>
/// <param name="xmlNode">The XML Schema extensions that describe the query.</param>
public SelectSchema(PropertySchema propertySchema, XmlNode xmlNode)
: base(propertySchema, xmlNode)
{
// Extract the selector (the operation that provides the transformation of one object to another) from the XML
// extension.
XmlAttribute selectorAttribute = xmlNode.Attributes[QualifiedName.Selector.Name, QualifiedName.Selector.Namespace];
this.selector = selectorAttribute.Value;
}
/// <summary>
/// Creates a description of an 'OrderBy' clause of a LINQ query.
/// </summary>
/// <param name="propertySchema">A description of a property.</param>
/// <param name="xmlNode">The XML Schema extension describing the 'OrderBy' clause.</param>
public OrderBySchema(PropertySchema propertySchema, XmlNode xmlNode)
: base(propertySchema, xmlNode)
{
// Extract the 'Comparer' clause.
XmlAttribute comparerAttribute = xmlNode.Attributes[QualifiedName.Comparer.Name, QualifiedName.Comparer.Namespace];
this.comparer = comparerAttribute.Value;
// Extract the 'KeySelector' clause.
XmlAttribute keySelectorAttribute = xmlNode.Attributes[QualifiedName.KeySelector.Name, QualifiedName.KeySelector.Namespace];
this.keySelector = keySelectorAttribute.Value;
// Extract the 'KeyType' clause.
XmlAttribute keyTypeAttribute = xmlNode.Attributes[QualifiedName.KeyType.Name, QualifiedName.KeyType.Namespace];
this.keyType = keyTypeAttribute.Value;
}
