Ejemplo n.º 1
0
// Evaluate an XPath. The returned result is stored in the struct. Call ReturnType to
// discover the type of result, and call one of the ResultAs* functions to return a
// copy of the result as a particular type.
func (xpath *XPath) Evaluate(nodePtr unsafe.Pointer, xpathExpr *Expression) (err error) {
	if nodePtr == nil {
		//evaluating xpath on a nil node returns no result.
		return
	}

	oldXPContextDoc := xpath.ContextPtr.doc
	oldXPContextNode := xpath.ContextPtr.node
	oldXPProximityPosition := xpath.ContextPtr.proximityPosition
	oldXPContextSize := xpath.ContextPtr.contextSize
	oldXPNsNr := xpath.ContextPtr.nsNr
	oldXPNamespaces := xpath.ContextPtr.namespaces

	xpath.ContextPtr.node = (*C.xmlNode)(nodePtr)
	if xpath.ResultPtr != nil {
		C.xmlXPathFreeObject(xpath.ResultPtr)
	}
	xpath.ResultPtr = C.xmlXPathCompiledEval(xpathExpr.Ptr, xpath.ContextPtr)

	xpath.ContextPtr.doc = oldXPContextDoc
	xpath.ContextPtr.node = oldXPContextNode
	xpath.ContextPtr.proximityPosition = oldXPProximityPosition
	xpath.ContextPtr.contextSize = oldXPContextSize
	xpath.ContextPtr.nsNr = oldXPNsNr
	xpath.ContextPtr.namespaces = oldXPNamespaces

	if xpath.ResultPtr == nil {
		err = errors.New("err in evaluating xpath: " + xpathExpr.String())
		return
	}
	return
}
Ejemplo n.º 2
0
//need to add an error as a return value b/c xpath evaluation can return error
func (xpath *XPath) Evaluate(nodePtr unsafe.Pointer, xpathExpr *Expression) (nodes []unsafe.Pointer, err error) {
	if nodePtr == nil {
		//evaluating xpath on a  nil node returns no result.
		return
	}
	xpath.ContextPtr.node = (*C.xmlNode)(nodePtr)
	if xpath.ResultPtr != nil {
		C.xmlXPathFreeObject(xpath.ResultPtr)
	}

	xpath.ResultPtr = C.xmlXPathCompiledEval(xpathExpr.Ptr, xpath.ContextPtr)
	if xpath.ResultPtr == nil {
		err = errors.New("err in evaluating xpath: " + xpathExpr.String())
		return
	}

	if nodesetPtr := xpath.ResultPtr.nodesetval; nodesetPtr != nil {
		if nodesetSize := int(nodesetPtr.nodeNr); nodesetSize > 0 {
			nodes = make([]unsafe.Pointer, nodesetSize)
			for i := 0; i < nodesetSize; i++ {
				nodes[i] = unsafe.Pointer(C.fetchNode(nodesetPtr, C.int(i)))
			}
		}
	}
	return
}
Ejemplo n.º 3
0
func (x *XPathContext) evalXPath(expr *XPathExpression) (*XPathObject, error) {
	if expr == nil {
		return nil, errors.New("empty XPathExpression")
	}

	// If there is no document associated with this context,
	// then xmlXPathCompiledEval() just fails to match
	ctx := x.ptr

	if ctx.node != nil && ctx.node.doc != nil {
		ctx.doc = ctx.node.doc
	}

	if ctx.doc == nil {
		ctx.doc = C.xmlNewDoc(stringToXmlChar("1.0"))
		defer C.xmlFreeDoc(ctx.doc)
	}

	res := C.xmlXPathCompiledEval(expr.ptr, ctx)
	if res == nil {
		return nil, errors.New("empty result")
	}

	return &XPathObject{ptr: res}, nil
}
Ejemplo n.º 4
0
func (xpath *XPath) Evaluate(nodePtr unsafe.Pointer, xpathExpr *Expression) (nodes []unsafe.Pointer) {
	if nodePtr == nil {
		return
	}
	xpath.ContextPtr.node = (*C.xmlNode)(nodePtr)
	if xpath.ResultPtr != nil {
		C.xmlXPathFreeObject(xpath.ResultPtr)
	}
	xpath.ResultPtr = C.xmlXPathCompiledEval(xpathExpr.Ptr, xpath.ContextPtr)
	if nodesetPtr := xpath.ResultPtr.nodesetval; nodesetPtr != nil {
		if nodesetSize := int(nodesetPtr.nodeNr); nodesetSize > 0 {
			nodes = make([]unsafe.Pointer, nodesetSize)
			for i := 0; i < nodesetSize; i++ {
				nodes[i] = unsafe.Pointer(C.fetchNode(nodesetPtr, C.int(i)))
			}
		}
	}
	return
}