IMailMergeDataSource

IMailMergeDataSource interface

Implement this interface to allow mail merge from a custom data source, such as a list of objects. Master-detail data is also supported.

public interface IMailMergeDataSource

Properties

Name Description
TableName { get; } Returns the name of the data source.

Methods

Name Description
GetChildDataSource(string) The Aspose.Words mail merge engine invokes this method when it encounters a beginning of a nested mail merge region.
GetValue(string, out object) Returns a value for the specified field name or false if the field is not found.
MoveNext() Advances to the next record in the data source.

Remarks

When a data source is created, it should be initialized to point to BOF (before the first record). The Aspose.Words mail merge engine will invoke MoveNext to advance to next record and then invoke GetValue for every merge field it encounters in the document or the current mail merge region.

Examples

Shows how to execute a mail merge with a data source in the form of a custom object.

public void CustomDataSource()
{
    Document doc = new Document();
    DocumentBuilder builder = new DocumentBuilder(doc);
    builder.InsertField(" MERGEFIELD FullName ");
    builder.InsertParagraph();
    builder.InsertField(" MERGEFIELD Address ");

    List<Customer> customers = new List<Customer>();
    customers.Add(new Customer("Thomas Hardy", "120 Hanover Sq., London"));
    customers.Add(new Customer("Paolo Accorti", "Via Monte Bianco 34, Torino"));

    // To use a custom object as a data source, it must implement the IMailMergeDataSource interface. 
    CustomerMailMergeDataSource dataSource = new CustomerMailMergeDataSource(customers);

    doc.MailMerge.Execute(dataSource);

    doc.Save(ArtifactsDir + "MailMergeCustom.CustomDataSource.docx");
}

/// <summary>
/// An example of a "data entity" class in your application.
/// </summary>
public class Customer
{
    public Customer(string aFullName, string anAddress)
    {
        FullName = aFullName;
        Address = anAddress;
    }

    public string FullName { get; set; }
    public string Address { get; set; }
}

/// <summary>
/// A custom mail merge data source that you implement to allow Aspose.Words 
/// to mail merge data from your Customer objects into Microsoft Word documents.
/// </summary>
public class CustomerMailMergeDataSource : IMailMergeDataSource
{
    public CustomerMailMergeDataSource(List<Customer> customers)
    {
        mCustomers = customers;

        // When we initialize the data source, its position must be before the first record.
        mRecordIndex = -1;
    }

    /// <summary>
    /// The name of the data source. Used by Aspose.Words only when executing mail merge with repeatable regions.
    /// </summary>
    public string TableName
    {
        get { return "Customer"; }
    }

    /// <summary>
    /// Aspose.Words calls this method to get a value for every data field.
    /// </summary>
    public bool GetValue(string fieldName, out object fieldValue)
    {
        switch (fieldName)
        {
            case "FullName":
                fieldValue = mCustomers[mRecordIndex].FullName;
                return true;
            case "Address":
                fieldValue = mCustomers[mRecordIndex].Address;
                return true;
            default:
                // Return "false" to the Aspose.Words mail merge engine to signify
                // that we could not find a field with this name.
                fieldValue = null;
                return false;
        }
    }

    /// <summary>
    /// A standard implementation for moving to a next record in a collection.
    /// </summary>
    public bool MoveNext()
    {
        if (!IsEof)
            mRecordIndex++;

        return !IsEof;
    }

    public IMailMergeDataSource GetChildDataSource(string tableName)
    {
        return null;
    }

    private bool IsEof
    {
        get { return (mRecordIndex >= mCustomers.Count); }
    }

    private readonly List<Customer> mCustomers;
    private int mRecordIndex;
}

See Also