DocumentVisitorVisitParagraphStart Method

public virtual VisitorAction VisitParagraphStart(
	Paragraph paragraph
)

Public Overridable Function VisitParagraphStart ( 
	paragraph As Paragraph
) As VisitorAction

public:
virtual VisitorAction VisitParagraphStart(
	Paragraph^ paragraph
)

abstract VisitParagraphStart : 
        paragraph : Paragraph -> VisitorAction 
override VisitParagraphStart : 
        paragraph : Paragraph -> VisitorAction 

public void DocStructureToText()
{
    // Open the document that has nodes we want to print the info of
    Document doc = new Document(MyDir + "DocumentVisitor-compatible features.docx");

    // Create an object that inherits from the DocumentVisitor class
    DocStructurePrinter visitor = new DocStructurePrinter();

    // Accepting a visitor lets it start traversing the nodes in the document, 
    // starting with the node that accepted it to then recursively visit every child
    doc.Accept(visitor);

    // Once the visiting is complete, we can retrieve the result of the operation,
    // that in this example, has accumulated in the visitor
    Console.WriteLine(visitor.GetText());
}

/// <summary>
/// This Visitor implementation prints information about sections, bodies, paragraphs and runs encountered in the document.
/// </summary>
public class DocStructurePrinter : DocumentVisitor
{
    public DocStructurePrinter()
    {
        mBuilder = new StringBuilder();
    }

    /// <summary>
    /// Gets the plain text of the document that was accumulated by the visitor.
    /// </summary>
    public string GetText()
    {
        return mBuilder.ToString();
    }

    /// <summary>
    /// Called when a Document node is encountered.
    /// </summary>
    public override VisitorAction VisitDocumentStart(Document doc)
    {
        int childNodeCount = doc.GetChildNodes(NodeType.Any, true).Count;

        // A Document node is at the root of every document, so if we let a document accept a visitor, this will be the first visitor action to be carried out
        IndentAndAppendLine("[Document start] Child nodes: " + childNodeCount);
        mDocTraversalDepth++;

        // Let the visitor continue visiting other nodes
        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when the visiting of a Document is ended.
    /// </summary>
    public override VisitorAction VisitDocumentEnd(Document doc)
    {
        // If we let a document accept a visitor, this will be the last visitor action to be carried out
        mDocTraversalDepth--;
        IndentAndAppendLine("[Document end]");

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a Section node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitSectionStart(Section section)
    {
        // Get the index of our section within the document
        NodeCollection docSections = section.Document.GetChildNodes(NodeType.Section, false);
        int sectionIndex = docSections.IndexOf(section);

        IndentAndAppendLine("[Section start] Section index: " + sectionIndex);
        mDocTraversalDepth++;

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when the visiting of a Section node is ended.
    /// </summary>
    public override VisitorAction VisitSectionEnd(Section section)
    {
        mDocTraversalDepth--;
        IndentAndAppendLine("[Section end]");

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a Body node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitBodyStart(Body body)
    {
        int paragraphCount = body.Paragraphs.Count;
        IndentAndAppendLine("[Body start] Paragraphs: " + paragraphCount);
        mDocTraversalDepth++;

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when the visiting of a Body node is ended.
    /// </summary>
    public override VisitorAction VisitBodyEnd(Body body)
    {
        mDocTraversalDepth--;
        IndentAndAppendLine("[Body end]");

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a Paragraph node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitParagraphStart(Paragraph paragraph)
    {
        IndentAndAppendLine("[Paragraph start]");
        mDocTraversalDepth++;

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when the visiting of a Paragraph node is ended.
    /// </summary>
    public override VisitorAction VisitParagraphEnd(Paragraph paragraph)
    {
        mDocTraversalDepth--;
        IndentAndAppendLine("[Paragraph end]");

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a Run node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitRun(Run run)
    {
        IndentAndAppendLine("[Run] \"" + run.GetText() + "\"");

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a SubDocument node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitSubDocument(SubDocument subDocument)
    {
        IndentAndAppendLine("[SubDocument]");

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Append a line to the StringBuilder and indent it depending on how deep the visitor is into the document tree.
    /// </summary>
    /// <param name="text"></param>
    private void IndentAndAppendLine(string text)
    {
        for (int i = 0; i < mDocTraversalDepth; i++) mBuilder.Append("|  ");

        mBuilder.AppendLine(text);
    }

    private int mDocTraversalDepth;
    private readonly StringBuilder mBuilder;
}

public void RemoveHiddenContentFromDocument()
{
    // Open the document we want to remove hidden content from.
    Document doc = new Document(MyDir + "Hidden content.docx");

    // Create an object that inherits from the DocumentVisitor class
    RemoveHiddenContentVisitor hiddenContentRemover = new RemoveHiddenContentVisitor();

    // This is the well known Visitor pattern. Get the model to accept a visitor
    // The model will iterate through itself by calling the corresponding methods
    // on the visitor object (this is called visiting)

    // We can run it over the entire the document like so
    doc.Accept(hiddenContentRemover);

    // Or we can run it on only a specific node
    Paragraph para = (Paragraph) doc.GetChild(NodeType.Paragraph, 4, true);
    para.Accept(hiddenContentRemover);

    // Or over a different type of node like below
    Table table = (Table) doc.GetChild(NodeType.Table, 0, true);
    table.Accept(hiddenContentRemover);

    doc.Save(ArtifactsDir + "Font.RemoveHiddenContentFromDocument.doc");

}

/// <summary>
/// This class when executed will remove all hidden content from the Document. Implemented as a Visitor.
/// </summary>
public class RemoveHiddenContentVisitor : DocumentVisitor
{
    /// <summary>
    /// Called when a FieldStart node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitFieldStart(FieldStart fieldStart)
    {
        // If this node is hidden, then remove it.
        if (IsHidden(fieldStart))
            fieldStart.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a FieldEnd node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitFieldEnd(FieldEnd fieldEnd)
    {
        if (IsHidden(fieldEnd))
            fieldEnd.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a FieldSeparator node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitFieldSeparator(FieldSeparator fieldSeparator)
    {
        if (IsHidden(fieldSeparator))
            fieldSeparator.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a Run node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitRun(Run run)
    {
        if (IsHidden(run))
            run.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a Paragraph node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitParagraphStart(Paragraph paragraph)
    {
        if (IsHidden(paragraph))
            paragraph.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a FormField is encountered in the document.
    /// </summary>
    public override VisitorAction VisitFormField(FormField formField)
    {
        if (IsHidden(formField))
            formField.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a GroupShape is encountered in the document.
    /// </summary>
    public override VisitorAction VisitGroupShapeStart(GroupShape groupShape)
    {
        if (IsHidden(groupShape))
            groupShape.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a Shape is encountered in the document.
    /// </summary>
    public override VisitorAction VisitShapeStart(Shape shape)
    {
        if (IsHidden(shape))
            shape.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a Comment is encountered in the document.
    /// </summary>
    public override VisitorAction VisitCommentStart(Comment comment)
    {
        if (IsHidden(comment))
            comment.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a Footnote is encountered in the document.
    /// </summary>
    public override VisitorAction VisitFootnoteStart(Footnote footnote)
    {
        if (IsHidden(footnote))
            footnote.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when visiting of a Table node is ended in the document.
    /// </summary>
    public override VisitorAction VisitTableEnd(Table table)
    {
        // At the moment there is no way to tell if a particular Table/Row/Cell is hidden. 
        // Instead, if the content of a table is hidden, then all inline child nodes of the table should be 
        // hidden and thus removed by previous visits as well. This will result in the container being empty
        // so if this is the case we know to remove the table node.
        // 
        // Note that a table which is not hidden but simply has no content will not be affected by this algorithm,
        // as technically they are not completely empty (for example a properly formed Cell will have at least 
        // an empty paragraph in it)
        if (!table.HasChildNodes)
            table.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when visiting of a Cell node is ended in the document.
    /// </summary>
    public override VisitorAction VisitCellEnd(Cell cell)
    {
        if (!cell.HasChildNodes && cell.ParentNode != null)
            cell.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when visiting of a Row node is ended in the document.
    /// </summary>
    public override VisitorAction VisitRowEnd(Row row)
    {
        if (!row.HasChildNodes && row.ParentNode != null)
            row.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a SpecialCharacter is encountered in the document.
    /// </summary>
    public override VisitorAction VisitSpecialChar(SpecialChar specialChar)
    {
        if (IsHidden(specialChar))
            specialChar.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Returns true if the node passed is set as hidden, returns false if it is visible.
    /// </summary>
    private static bool IsHidden(Node node)
    {
        switch (node)
        {
            case Inline currentNode:
                // If the node is Inline then cast it to retrieve the Font property which contains the hidden property
                return currentNode.Font.Hidden;
            default:
                switch (node.NodeType)
                {
                    case NodeType.Paragraph:
                    {
                        // If the node is a paragraph cast it to retrieve the ParagraphBreakFont which contains the hidden property
                        Paragraph para = (Paragraph) node;
                        return para.ParagraphBreakFont.Hidden;
                    }
                    default:
                        switch (node)
                        {
                            case ShapeBase shape:
                                // Node is a shape or groupshape
                                return shape.Font.Hidden;
                            case InlineStory inlineStory:
                                // Node is a comment or footnote
                                return inlineStory.Font.Hidden;
                        }

                        break;
                }

                break;
        }

        // A node that is passed to this method which does not contain a hidden property will end up here
        // By default nodes are not hidden so return false
        return false;
    }
}