Aspose::Words::DocumentVisitor::VisitParagraphStart method
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]DocumentVisitor::VisitParagraphStart method
Called when enumeration of a paragraph has started.
virtual Aspose::Words::VisitorAction Aspose::Words::DocumentVisitor::VisitParagraphStart(System::SharedPtr<Aspose::Words::Paragraph> paragraph)
Parameter | Type | Description |
---|---|---|
paragraph | System::SharedPtr<Aspose::Words::Paragraph> | The object that is being visited. |
ReturnValue
A VisitorAction value that specifies how to continue the enumeration.
Examples
Shows how to use a document visitor to print a document’s node structure.
void DocStructureToText()
{
auto doc = MakeObject<Document>(MyDir + u"DocumentVisitor-compatible features.docx");
auto visitor = MakeObject<ExDocumentVisitor::DocStructurePrinter>();
// When we get a composite node to accept a document visitor, the visitor visits the accepting node,
// and then traverses all the node's children in a depth-first manner.
// The visitor can read and modify each visited node.
doc->Accept(visitor);
std::cout << visitor->GetText() << std::endl;
}
class DocStructurePrinter : public DocumentVisitor
{
public:
DocStructurePrinter() : mDocTraversalDepth(0)
{
mAcceptingNodeChildTree = MakeObject<System::Text::StringBuilder>();
}
String GetText()
{
return mAcceptingNodeChildTree->ToString();
}
VisitorAction VisitDocumentStart(SharedPtr<Document> doc) override
{
int childNodeCount = doc->GetChildNodes(NodeType::Any, true)->get_Count();
IndentAndAppendLine(String(u"[Document start] Child nodes: ") + childNodeCount);
mDocTraversalDepth++;
// Allow the visitor to continue visiting other nodes.
return VisitorAction::Continue;
}
VisitorAction VisitDocumentEnd(SharedPtr<Document> doc) override
{
mDocTraversalDepth--;
IndentAndAppendLine(u"[Document end]");
return VisitorAction::Continue;
}
VisitorAction VisitSectionStart(SharedPtr<Section> section) override
{
// Get the index of our section within the document.
SharedPtr<NodeCollection> docSections = section->get_Document()->GetChildNodes(NodeType::Section, false);
int sectionIndex = docSections->IndexOf(section);
IndentAndAppendLine(String(u"[Section start] Section index: ") + sectionIndex);
mDocTraversalDepth++;
return VisitorAction::Continue;
}
VisitorAction VisitSectionEnd(SharedPtr<Section> section) override
{
mDocTraversalDepth--;
IndentAndAppendLine(u"[Section end]");
return VisitorAction::Continue;
}
VisitorAction VisitBodyStart(SharedPtr<Body> body) override
{
int paragraphCount = body->get_Paragraphs()->get_Count();
IndentAndAppendLine(String(u"[Body start] Paragraphs: ") + paragraphCount);
mDocTraversalDepth++;
return VisitorAction::Continue;
}
VisitorAction VisitBodyEnd(SharedPtr<Body> body) override
{
mDocTraversalDepth--;
IndentAndAppendLine(u"[Body end]");
return VisitorAction::Continue;
}
VisitorAction VisitParagraphStart(SharedPtr<Paragraph> paragraph) override
{
IndentAndAppendLine(u"[Paragraph start]");
mDocTraversalDepth++;
return VisitorAction::Continue;
}
VisitorAction VisitParagraphEnd(SharedPtr<Paragraph> paragraph) override
{
mDocTraversalDepth--;
IndentAndAppendLine(u"[Paragraph end]");
return VisitorAction::Continue;
}
VisitorAction VisitRun(SharedPtr<Run> run) override
{
IndentAndAppendLine(String(u"[Run] \"") + run->GetText() + u"\"");
return VisitorAction::Continue;
}
VisitorAction VisitSubDocument(SharedPtr<SubDocument> subDocument) override
{
IndentAndAppendLine(u"[SubDocument]");
return VisitorAction::Continue;
}
private:
int mDocTraversalDepth;
SharedPtr<System::Text::StringBuilder> mAcceptingNodeChildTree;
void IndentAndAppendLine(String text)
{
for (int i = 0; i < mDocTraversalDepth; i++)
{
mAcceptingNodeChildTree->Append(u"| ");
}
mAcceptingNodeChildTree->AppendLine(text);
}
};
Shows how to use a DocumentVisitor implementation to remove all hidden content from a document.
void RemoveHiddenContentFromDocument()
{
auto doc = MakeObject<Document>(MyDir + u"Hidden content.docx");
auto hiddenContentRemover = MakeObject<ExFont::RemoveHiddenContentVisitor>();
// Below are three types of fields which can accept a document visitor,
// which will allow it to visit the accepting node, and then traverse its child nodes in a depth-first manner.
// 1 - Paragraph node:
auto para = System::ExplicitCast<Paragraph>(doc->GetChild(NodeType::Paragraph, 4, true));
para->Accept(hiddenContentRemover);
// 2 - Table node:
SharedPtr<Table> table = doc->get_FirstSection()->get_Body()->get_Tables()->idx_get(0);
table->Accept(hiddenContentRemover);
// 3 - Document node:
doc->Accept(hiddenContentRemover);
doc->Save(ArtifactsDir + u"Font.RemoveHiddenContentFromDocument.docx");
}
class RemoveHiddenContentVisitor : public DocumentVisitor
{
public:
VisitorAction VisitFieldStart(SharedPtr<FieldStart> fieldStart) override
{
if (fieldStart->get_Font()->get_Hidden())
{
fieldStart->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitFieldEnd(SharedPtr<FieldEnd> fieldEnd) override
{
if (fieldEnd->get_Font()->get_Hidden())
{
fieldEnd->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitFieldSeparator(SharedPtr<FieldSeparator> fieldSeparator) override
{
if (fieldSeparator->get_Font()->get_Hidden())
{
fieldSeparator->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitRun(SharedPtr<Run> run) override
{
if (run->get_Font()->get_Hidden())
{
run->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitParagraphStart(SharedPtr<Paragraph> paragraph) override
{
if (paragraph->get_ParagraphBreakFont()->get_Hidden())
{
paragraph->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitFormField(SharedPtr<FormField> formField) override
{
if (formField->get_Font()->get_Hidden())
{
formField->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitGroupShapeStart(SharedPtr<GroupShape> groupShape) override
{
if (groupShape->get_Font()->get_Hidden())
{
groupShape->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitShapeStart(SharedPtr<Shape> shape) override
{
if (shape->get_Font()->get_Hidden())
{
shape->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitCommentStart(SharedPtr<Comment> comment) override
{
if (comment->get_Font()->get_Hidden())
{
comment->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitFootnoteStart(SharedPtr<Footnote> footnote) override
{
if (footnote->get_Font()->get_Hidden())
{
footnote->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitSpecialChar(SharedPtr<SpecialChar> specialChar) override
{
if (specialChar->get_Font()->get_Hidden())
{
specialChar->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitTableEnd(SharedPtr<Table> table) override
{
// The content inside table cells may have the hidden content flag, but the tables themselves cannot.
// If this table had nothing but hidden content, this visitor would have removed all of it,
// and there would be no child nodes left.
// Thus, we can also treat the table itself as hidden content and remove it.
// Tables which are empty but do not have hidden content will have cells with empty paragraphs inside,
// which this visitor will not remove.
if (!table->get_HasChildNodes())
{
table->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitCellEnd(SharedPtr<Cell> cell) override
{
if (!cell->get_HasChildNodes() && cell->get_ParentNode() != nullptr)
{
cell->Remove();
}
return VisitorAction::Continue;
}
VisitorAction VisitRowEnd(SharedPtr<Row> row) override
{
if (!row->get_HasChildNodes() && row->get_ParentNode() != nullptr)
{
row->Remove();
}
return VisitorAction::Continue;
}
};
See Also
- Enum VisitorAction
- Class Paragraph
- Class DocumentVisitor
- Namespace Aspose::Words
- Library Aspose.Words for C++