AcceptStart

Cell.AcceptStart method

Accepts a visitor for visiting the start of the cell.

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

Return Value

The action to be taken by the visitor.

Examples

Shows how to print the node structure of every table in a document.

public void TableToText()
{
    Document doc = new Document(MyDir + "DocumentVisitor-compatible features.docx");
    TableStructurePrinter visitor = new TableStructurePrinter();

    // 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);

    Console.WriteLine(visitor.GetText());
}

/// <summary>
/// Traverses a node's non-binary tree of child nodes.
/// Creates a map in the form of a string of all encountered Table nodes and their children.
/// </summary>
public class TableStructurePrinter : DocumentVisitor
{
    public TableStructurePrinter()
    {
        mVisitedTables = new StringBuilder();
        mVisitorIsInsideTable = false;
    }

    public string GetText()
    {
        return mVisitedTables.ToString();
    }

    /// <summary>
    /// Called when a Run node is encountered in the document.
    /// Runs that are not within tables are not recorded.
    /// </summary>
    public override VisitorAction VisitRun(Run run)
    {
        if (mVisitorIsInsideTable) IndentAndAppendLine("[Run] \"" + run.GetText() + "\"");

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a Table is encountered in the document.
    /// </summary>
    public override VisitorAction VisitTableStart(Table table)
    {
        int rows = 0;
        int columns = 0;

        if (table.Rows.Count > 0)
        {
            rows = table.Rows.Count;
            columns = table.FirstRow.Count;
        }

        IndentAndAppendLine("[Table start] Size: " + rows + "x" + columns);
        mDocTraversalDepth++;
        mVisitorIsInsideTable = true;

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called after all the child nodes of a Table node have been visited.
    /// </summary>
    public override VisitorAction VisitTableEnd(Table table)
    {
        mDocTraversalDepth--;
        IndentAndAppendLine("[Table end]");
        mVisitorIsInsideTable = false;

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a Row node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitRowStart(Row row)
    {
        string rowContents = row.GetText().TrimEnd(new []{ '\u0007', ' ' }).Replace("\u0007", ", ");
        int rowWidth = row.IndexOf(row.LastCell) + 1;
        int rowIndex = row.ParentTable.IndexOf(row);
        string rowStatusInTable = row.IsFirstRow && row.IsLastRow ? "only" : row.IsFirstRow ? "first" : row.IsLastRow ? "last" : "";
        if (rowStatusInTable != "")
        {
            rowStatusInTable = $", the {rowStatusInTable} row in this table,";
        }

        IndentAndAppendLine($"[Row start] Row #{++rowIndex}{rowStatusInTable} width {rowWidth}, \"{rowContents}\"");
        mDocTraversalDepth++;

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called after all the child nodes of a Row node have been visited.
    /// </summary>
    public override VisitorAction VisitRowEnd(Row row)
    {
        mDocTraversalDepth--;
        IndentAndAppendLine("[Row end]");

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when a Cell node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitCellStart(Cell cell)
    {
        Row row = cell.ParentRow;
        Table table = row.ParentTable;
        string cellStatusInRow = cell.IsFirstCell && cell.IsLastCell ? "only" : cell.IsFirstCell ? "first" : cell.IsLastCell ? "last" : "";
        if (cellStatusInRow != "")
        {
            cellStatusInRow = $", the {cellStatusInRow} cell in this row";
        }

        IndentAndAppendLine($"[Cell start] Row {table.IndexOf(row) + 1}, Col {row.IndexOf(cell) + 1}{cellStatusInRow}");
        mDocTraversalDepth++;

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called after all the child nodes of a Cell node have been visited.
    /// </summary>
    public override VisitorAction VisitCellEnd(Cell cell)
    {
        mDocTraversalDepth--;
        IndentAndAppendLine("[Cell end]");
        return VisitorAction.Continue;
    }

    /// <summary>
    /// Append a line to the StringBuilder, and indent it depending on how deep the visitor is
    /// into the current table's tree of child nodes.
    /// </summary>
    /// <param name="text"></param>
    private void IndentAndAppendLine(string text)
    {
        for (int i = 0; i < mDocTraversalDepth; i++)
        {
            mVisitedTables.Append("|  ");
        }

        mVisitedTables.AppendLine(text);
    }

    private bool mVisitorIsInsideTable;
    private int mDocTraversalDepth;
    private readonly StringBuilder mVisitedTables;
}

See Also

Cell.AcceptEnd Cell.EnsureMinimum