AcceptStart

Paragraph.AcceptStart method

Accepts a visitor for visiting the start of the document’s paragraph.

public override VisitorAction AcceptStart(DocumentVisitor visitor)
ParameterTypeDescription
visitorDocumentVisitorThe document visitor.

Return Value

The action to be taken by the visitor.

Examples

Shows how to use a DocumentVisitor implementation to remove all hidden content from a document.

public void RemoveHiddenContentFromDocument()
{
    Document doc = new Document(MyDir + "Hidden content.docx");
    RemoveHiddenContentVisitor hiddenContentRemover = new 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:
    Paragraph para = (Paragraph)doc.GetChild(NodeType.Paragraph, 4, true);
    para.Accept(hiddenContentRemover);

    // 2 -  Table node:
    Table table = doc.FirstSection.Body.Tables[0];
    table.Accept(hiddenContentRemover);

    // 3 -  Document node:
    doc.Accept(hiddenContentRemover);

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

/// <summary>
/// Removes all visited nodes marked as "hidden content".
/// </summary>
public class RemoveHiddenContentVisitor : DocumentVisitor
{
    /// <summary>
    /// Called when a FieldStart node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitFieldStart(FieldStart fieldStart)
    {
        if (fieldStart.Font.Hidden)
            fieldStart.Remove();

        return VisitorAction.Continue;
    }

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

        return VisitorAction.Continue;
    }

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

        return VisitorAction.Continue;
    }

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

        return VisitorAction.Continue;
    }

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

        return VisitorAction.Continue;
    }

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

        return VisitorAction.Continue;
    }

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

        return VisitorAction.Continue;
    }

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

        return VisitorAction.Continue;
    }

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

        return VisitorAction.Continue;
    }

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

        return VisitorAction.Continue;
    }

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

        if (specialChar.Font.Hidden)
            specialChar.Remove();

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when visiting of a Table node is ended in the document.
    /// </summary>
    public override VisitorAction VisitTableEnd(Table table)
    {
        // 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.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;
    }
}

See Also

Paragraph.AcceptEnd Paragraph.AppendField