20. The computer-readable storage medium of claim 19 , wherein the at least one object property is configured to at least one of: determine a format of error messages presented by the XML schema validation model related to schema file validations; access one or more individual members of an XML child node suggestions collection as defined by an associated XML schema file and current editing context within a document associated with the XML schema file; insert an XML element into a document whereby the object method includes a range parameter for pointing to a part of the document where the XML element is to be inserted; customize schema validation error notifications from the XML schema validation model; request validation of a specified XML element applied to a document; attach a user-specified XML schema file to a document; save a document as an XML document where saving the document as an XML document violates an associated XML schema file; cause the XML schema validation model to allow mixed content data entry into a document where the mixed content data entry otherwise violates an associated XML schema file; access a specified XML schema file associated with a document from a collection of XML schema file references whereby a parameter associated with the specified XML schema reference is passed to the XML schema validation model with the object method; control whether XML schema violations are highlighted in a document by the XML schema validation model; require the XML schema validation model to validate a document against all XML schema files associated with the document; remove an XML schema file reference from a document and for removing the XML schema file reference from a schema file references collection; and re-associate a specified schema file with a document where the specified schema file was previously removed from association with the document.
19. A computer-readable storage medium storing instructions executable by a computer system to yield a result, comprising instructions to: provide an interface to an XML schema validation model associated with a programming object to receive a modification to one or more XML schemas to be used by the XML schema validation model presented to validate one or more XML documents presented to the programming object; wherein the interface includes one of: an application programming interface providing access to the XML schema validation model; and a set of message calls to which the XML schema validation model is responsive; configure the interface to receive at least one object property configured to: modify operation of the XML schema validation model; modify an XML schema used by the XML schema validation model; and add an additional XML scheme for use by the XML schema validation model; direct the XML validation model to apply at least one of the modified XML schema and the additional XML schema to validate the one or more XML documents; and one or more additional object properties to which the XML schema validation model will provide information via the interface, the information including one or more of: a list of all XML schema files associated with a document; a description text of a specified XML schema violation for a specified XML element applied to a document; a location of a specified XML schema file; a Namespace uniform resource identifier associated with a specified XML schema file; a list of all XML elements suggested by the application program based on an XML schema file associated with a document and based on an editing context within the document; and a list of all XML elements in a document associated with an XML schema violation based on an associated XML schema file.