AcceptStart

OfficeMath.AcceptStart method

Accepts a visitor for visiting the start of the office math.

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 office math node in a document.

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

    // 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 OfficeMath nodes and their children.
/// </summary>
public class OfficeMathStructurePrinter : DocumentVisitor
{
    public OfficeMathStructurePrinter()
    {
        mBuilder = new StringBuilder();
        mVisitorIsInsideOfficeMath = false;
    }

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

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called when an OfficeMath node is encountered in the document.
    /// </summary>
    public override VisitorAction VisitOfficeMathStart(OfficeMath officeMath)
    {
        IndentAndAppendLine("[OfficeMath start] Math object type: " + officeMath.MathObjectType);
        mDocTraversalDepth++;
        mVisitorIsInsideOfficeMath = true;

        return VisitorAction.Continue;
    }

    /// <summary>
    /// Called after all the child nodes of an OfficeMath node have been visited.
    /// </summary>
    public override VisitorAction VisitOfficeMathEnd(OfficeMath officeMath)
    {
        mDocTraversalDepth--;
        IndentAndAppendLine("[OfficeMath end]");
        mVisitorIsInsideOfficeMath = false;

        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 bool mVisitorIsInsideOfficeMath;
    private int mDocTraversalDepth;
    private readonly StringBuilder mBuilder;
}

See Also

OfficeMath.AcceptEnd OfficeMath.GetMathRenderer