mirror of
https://gitlab.com/freepascal.org/fpc/source.git
synced 2025-04-21 01:09:31 +02:00
* Refactored TXPathLocationPathNode.Evaluate(), split that awful 3-level nested procedure into
TStep.SelectNodes, TStep.ApplyPredicates and the remaining part.
* Since predicates contained in a location path are evaluated within separate contexts of their own,
evaluation of the location path itself does not require a full context (only need context nodes).
This simplifies things quite a bit.
+ Added support for evaluating filter expressions follwed by location path. Things like
"id('foo')/bar" work now.
git-svn-id: trunk@13244 -
This commit is contained in:
sergei
parent
ba951580a2
commit
26767125f0
@ -240,7 +240,12 @@ type
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TNodeTestType = (ntAnyPrincipal, ntName, ntTextNode,
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ntCommentNode, ntPINode, ntAnyNode);
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TNodeSet = TFPList;
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TStep = class
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private
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procedure SelectNodes(ANode: TDOMNode; out ResultNodes: TNodeSet);
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procedure ApplyPredicates(Nodes: TNodeSet; AEnvironment: TXPathEnvironment);
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public
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NextStep: TStep;
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Axis: TAxis;
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@ -263,9 +268,6 @@ type
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AEnvironment: TXPathEnvironment): TXPathVariable; override;
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end;
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TNodeSet = TFPList;
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{ Exceptions }
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EXPathEvaluationError = class(Exception);
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@ -1067,6 +1069,198 @@ begin
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inherited destroy;
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end;
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procedure TStep.SelectNodes(ANode: TDOMNode; out ResultNodes: TNodeSet);
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var
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Node, Node2: TDOMNode;
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Attr: TDOMNamedNodeMap;
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i: Integer;
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TempList: TFPList;
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procedure DoNodeTest(Node: TDOMNode);
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begin
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case NodeTestType of
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ntAnyPrincipal:
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// !!!: Probably this isn't ready for namespace support yet
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if (Axis <> axisAttribute) and
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(Node.NodeType <> ELEMENT_NODE) then
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exit;
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ntName:
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if Node.NodeName <> NodeTestString then
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exit;
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ntTextNode:
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if not Node.InheritsFrom(TDOMCharacterData) then
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exit;
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ntCommentNode:
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if Node.NodeType <> COMMENT_NODE then
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exit;
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ntPINode:
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if Node.NodeType <> PROCESSING_INSTRUCTION_NODE then
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exit;
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end;
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if ResultNodes.IndexOf(Node) < 0 then
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ResultNodes.Add(Node);
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end;
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procedure AddDescendants(CurNode: TDOMNode);
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var
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Child: TDOMNode;
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begin
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Child := CurNode.FirstChild;
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while Assigned(Child) do
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begin
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DoNodeTest(Child);
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AddDescendants(Child);
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Child := Child.NextSibling;
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end;
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end;
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begin
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ResultNodes := TNodeSet.Create;
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case Axis of
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axisAncestor:
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begin
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Node := ANode.ParentNode;
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while Assigned(Node) do
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begin
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DoNodeTest(Node);
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Node := Node.ParentNode;
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end;
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end;
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axisAncestorOrSelf:
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begin
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Node := ANode;
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repeat
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DoNodeTest(Node);
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Node := Node.ParentNode;
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until not Assigned(Node);
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end;
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axisAttribute:
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begin
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Attr := ANode.Attributes;
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if Assigned(Attr) then
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for i := 0 to Attr.Length - 1 do
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DoNodeTest(Attr[i]);
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end;
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axisChild:
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begin
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Node := ANode.FirstChild;
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while Assigned(Node) do
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begin
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DoNodeTest(Node);
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Node := Node.NextSibling;
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end;
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end;
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axisDescendant:
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AddDescendants(ANode);
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axisDescendantOrSelf:
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begin
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DoNodeTest(ANode);
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AddDescendants(ANode);
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end;
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axisFollowing:
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begin
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Node := ANode;
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repeat
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Node2 := Node.NextSibling;
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while Assigned(Node2) do
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begin
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DoNodeTest(Node2);
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AddDescendants(Node2);
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Node2 := Node2.NextSibling;
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end;
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Node := Node.ParentNode;
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until not Assigned(Node);
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end;
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axisFollowingSibling:
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begin
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Node := ANode.NextSibling;
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while Assigned(Node) do
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begin
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DoNodeTest(Node);
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Node := Node.NextSibling;
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end;
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end;
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{axisNamespace: !!!: Not supported yet}
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axisParent:
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if Assigned(ANode.ParentNode) then
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DoNodeTest(ANode.ParentNode);
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axisPreceding:
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begin
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TempList := TFPList.Create;
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try
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Node := ANode;
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// build list of ancestors
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while Assigned(Node) do
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begin
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TempList.Add(Node);
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Node := Node.ParentNode;
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end;
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// then process it in reverse order
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for i := TempList.Count-1 downto 1 do
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begin
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Node := TDOMNode(TempList[i]);
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Node2 := Node.FirstChild;
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while Assigned(Node2) and (Node2 <> TDOMNode(TempList[i-1])) do
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begin
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DoNodeTest(Node2);
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AddDescendants(Node2);
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Node2 := Node2.NextSibling;
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end;
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end;
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finally
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TempList.Free;
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end;
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end;
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axisPrecedingSibling:
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begin
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if Assigned(ANode.ParentNode) then
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begin
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Node := ANode.ParentNode.FirstChild;
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while Assigned(Node) and (Node <> ANode) do
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begin
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DoNodeTest(Node);
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Node := Node.NextSibling;
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end;
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end;
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end;
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axisSelf:
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DoNodeTest(ANode);
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end;
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end;
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{ Filter the nodes of this step using the predicates: The current
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node set is filtered, nodes not passing the filter are replaced
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by nil. After one filter has been applied, Nodes is packed, and
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the next filter will be processed. }
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procedure TStep.ApplyPredicates(Nodes: TNodeSet; AEnvironment: TXPathEnvironment);
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var
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i, j: Integer;
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NewContext: TXPathContext;
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begin
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for i := 0 to High(Predicates) do
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begin
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NewContext := TXPathContext.Create(nil, 0, Nodes.Count);
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try
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for j := 0 to Nodes.Count - 1 do
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begin
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// ContextPosition must honor the axis direction
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if Axis in [axisAncestor, axisAncestorOrSelf,
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axisPreceding, axisPrecedingSibling] then
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NewContext.ContextPosition := Nodes.Count - j
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else
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NewContext.ContextPosition := j+1;
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NewContext.ContextNode := TDOMNode(Nodes[j]);
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if not Predicates[i].EvalPredicate(NewContext, AEnvironment) then
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Nodes[j] := nil;
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end;
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Nodes.Pack;
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finally
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NewContext.Free;
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end;
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end;
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end;
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constructor TXPathLocationPathNode.Create(ALeft: TXPathExprNode; AIsAbsolutePath: Boolean);
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begin
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inherited Create;
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@ -1078,251 +1272,56 @@ function TXPathLocationPathNode.Evaluate(AContext: TXPathContext;
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AEnvironment: TXPathEnvironment): TXPathVariable;
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var
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ResultNodeSet: TNodeSet;
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LeftResult: TXPathVariable;
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i: Integer;
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procedure EvaluateStep(AStep: TStep; AContext: TXPathContext);
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procedure EvaluateStep(AStep: TStep; AContextNode: TDOMNode);
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var
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StepNodes: TFPList;
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procedure DoNodeTest(Node: TDOMNode);
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begin
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case AStep.NodeTestType of
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ntAnyPrincipal:
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// !!!: Probably this isn't ready for namespace support yet
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if (AStep.Axis <> axisAttribute) and
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(Node.NodeType <> ELEMENT_NODE) then
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exit;
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ntName:
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if Node.NodeName <> AStep.NodeTestString then
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exit;
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ntTextNode:
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if not Node.InheritsFrom(TDOMCharacterData) then
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exit;
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ntCommentNode:
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if Node.NodeType <> COMMENT_NODE then
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exit;
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ntPINode:
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if Node.NodeType <> PROCESSING_INSTRUCTION_NODE then
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exit;
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end;
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if StepNodes.IndexOf(Node) < 0 then
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StepNodes.Add(Node);
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end;
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procedure AddDescendants(CurNode: TDOMNode);
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var
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Child: TDOMNode;
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begin
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Child := CurNode.FirstChild;
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while Assigned(Child) do
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begin
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DoNodeTest(Child);
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AddDescendants(Child);
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Child := Child.NextSibling;
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end;
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end;
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var
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Node, Node2: TDOMNode;
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Attr: TDOMNamedNodeMap;
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i, j: Integer;
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NewContext: TXPathContext;
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Predicate: TXPathExprNode;
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TempList: TFPList;
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Node: TDOMNode;
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i: Integer;
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begin
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StepNodes := TFPList.Create;
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// !!!: Protect this with an try/finally block
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case AStep.Axis of
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axisAncestor:
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begin
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Node := AContext.ContextNode.ParentNode;
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while Assigned(Node) do
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begin
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DoNodeTest(Node);
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Node := Node.ParentNode;
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end;
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end;
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axisAncestorOrSelf:
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begin
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Node := AContext.ContextNode;
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repeat
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DoNodeTest(Node);
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Node := Node.ParentNode;
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until not Assigned(Node);
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end;
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axisAttribute:
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begin
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Attr := AContext.ContextNode.Attributes;
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if Assigned(Attr) then
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for i := 0 to Attr.Length - 1 do
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DoNodeTest(Attr[i]);
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end;
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axisChild:
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begin
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Node := AContext.ContextNode.FirstChild;
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while Assigned(Node) do
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begin
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DoNodeTest(Node);
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Node := Node.NextSibling;
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end;
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end;
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axisDescendant:
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AddDescendants(AContext.ContextNode);
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axisDescendantOrSelf:
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begin
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DoNodeTest(AContext.ContextNode);
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AddDescendants(AContext.ContextNode);
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end;
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axisFollowing:
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begin
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Node := AContext.ContextNode;
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repeat
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Node2 := Node.NextSibling;
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while Assigned(Node2) do
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begin
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DoNodeTest(Node2);
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AddDescendants(Node2);
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Node2 := Node2.NextSibling;
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end;
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Node := Node.ParentNode;
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until not Assigned(Node);
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end;
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axisFollowingSibling:
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begin
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Node := AContext.ContextNode.NextSibling;
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while Assigned(Node) do
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begin
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DoNodeTest(Node);
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Node := Node.NextSibling;
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end;
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end;
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{axisNamespace: !!!: Not supported yet}
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axisParent:
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if Assigned(AContext.ContextNode.ParentNode) then
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DoNodeTest(AContext.ContextNode);
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axisPreceding:
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begin
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TempList := TFPList.Create;
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try
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Node := AContext.ContextNode;
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// build list of ancestors
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while Assigned(Node) do
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begin
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TempList.Add(Node);
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Node := Node.ParentNode;
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end;
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// then process it in reverse order
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for i := TempList.Count-1 downto 1 do
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begin
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Node := TDOMNode(TempList[i]);
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Node2 := Node.FirstChild;
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while Assigned(Node2) and (Node2 <> TDOMNode(TempList[i-1])) do
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begin
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DoNodeTest(Node2);
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AddDescendants(Node2);
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Node2 := Node2.NextSibling;
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end;
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end;
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finally
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TempList.Free;
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end;
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end;
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axisPrecedingSibling:
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begin
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if Assigned(AContext.ContextNode.ParentNode) then
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begin
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Node := AContext.ContextNode.ParentNode.FirstChild;
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while Assigned(Node) and (Node <> AContext.ContextNode) do
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begin
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DoNodeTest(Node);
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Node := Node.NextSibling;
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end;
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end;
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end;
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axisSelf:
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DoNodeTest(AContext.ContextNode);
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end;
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AStep.SelectNodes(AContextNode, StepNodes);
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try
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AStep.ApplyPredicates(StepNodes, AEnvironment);
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{ Filter the nodes of this step using the predicates: The current
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node set (StepNodes) is filtered, nodes not passing the filter
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are replaced by nil. After one filter has been applied, StepNodes
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is packed, and the next filter will be processed.
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The final result will then be passed to the next step, or added
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to the result of the LocationPath if this is the last step. }
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for i := 0 to High(AStep.Predicates) do
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begin
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NewContext := TXPathContext.Create(nil, 0, StepNodes.Count);
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try
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Predicate := AStep.Predicates[i];
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for j := 0 to StepNodes.Count - 1 do
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begin
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// ContextPosition must honor the axis direction
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if AStep.Axis in [axisAncestor, axisAncestorOrSelf,
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axisPreceding, axisPrecedingSibling] then
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NewContext.ContextPosition := StepNodes.Count - j
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else
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NewContext.ContextPosition := j+1;
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Node := TDOMNode(StepNodes[j]);
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NewContext.ContextNode := Node;
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if not Predicate.EvalPredicate(NewContext, AEnvironment) then
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StepNodes[j] := nil;
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end;
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StepNodes.Pack;
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finally
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NewContext.Free;
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end;
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end;
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if Assigned(AStep.NextStep) then
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begin
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NewContext := TXPathContext.Create(nil, 0, StepNodes.Count);
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try
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if Assigned(AStep.NextStep) then
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begin
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for i := 0 to StepNodes.Count - 1 do
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EvaluateStep(AStep.NextStep, TDOMNode(StepNodes[i]));
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end else
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begin
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// Only add nodes to result if it isn't duplicate
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for i := 0 to StepNodes.Count - 1 do
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begin
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NewContext.ContextNode := TDOMNode(StepNodes[i]);
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Inc(NewContext.ContextPosition);
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EvaluateStep(AStep.NextStep, NewContext);
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Node := TDOMNode(StepNodes[i]);
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if ResultNodeSet.IndexOf(Node) < 0 then
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ResultNodeSet.Add(Node);
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end;
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finally
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NewContext.Free;
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end;
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end else
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begin
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// Only add nodes to result if it isn't duplicate
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for i := 0 to StepNodes.Count - 1 do
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begin
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Node := TDOMNode(StepNodes[i]);
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if ResultNodeSet.IndexOf(Node) < 0 then
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ResultNodeSet.Add(Node);
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end;
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finally
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StepNodes.Free;
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end;
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StepNodes.Free;
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end;
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var
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NewContext: TXPathContext;
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begin
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ResultNodeSet := TNodeSet.Create;
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try
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if FIsAbsolutePath then
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if Assigned(FLeft) then
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begin
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if AContext.ContextNode.NodeType = DOCUMENT_NODE then
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NewContext := TXPathContext.Create(AContext.ContextNode, 1, 1)
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else
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NewContext := TXPathContext.Create(AContext.ContextNode.OwnerDocument,
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1, 1);
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LeftResult := FLeft.Evaluate(AContext, AEnvironment);
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try
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EvaluateStep(FFirstStep, NewContext);
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with LeftResult.AsNodeSet do
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for i := 0 to Count-1 do
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EvaluateStep(FFirstStep, TDOMNode(Items[i]));
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finally
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NewContext.Free;
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LeftResult.Release;
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end;
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end
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else if FIsAbsolutePath and (AContext.ContextNode.NodeType <> DOCUMENT_NODE) then
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EvaluateStep(FFirstStep, AContext.ContextNode.OwnerDocument)
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else
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EvaluateStep(FFirstStep, AContext);
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EvaluateStep(FFirstStep, AContext.ContextNode);
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except
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ResultNodeSet.Free;
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raise;
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