Programming with Exchange Server 2007 (EWS) - Part 3

Background

In my last article, I discussed how to read different folders like inbox, sent items etc., and also do a search on the basis of some criteria.

My previous articles on this series include:

1. Programming with Exchange Server 2007 (EWS) - Part 1
2. Programming with Exchange Server 2007 (EWS) - Part 2

In this part, first, I'll discuss reading the details of a mail from the inbox, and also cover the mystery behind extended properties. The key points are:

• Introduction
• Reading Mails
• Setting Read Mails as Read
• Extended Properties - Intro
• Extended Properties - How to set them
• Extended Properties - How to read them

Introduction

Every mail is of type MessageType or is inherited from MessageType, so we can access all the items from the inbox as MessageType even mails related to Calendaring.

Reading Mails

To read the details of a mail, we need to use the GetItem API provided by EWS, as:

public void GetSignalDetails(ItemIdType p_strItemId)
{
    GetItemType MailId = new GetItemType();
    GetItemResponseType mailResponse;
    string strMsg = string.Empty;

    MailId.ItemIds = new BaseItemIdType[] { idType };
    MailId.ItemShape = new ItemResponseShapeType();
    MailId.ItemShape.BaseShape = DefaultShapeNamesType.AllProperties;
    mailResponse = _esb.GetItem(MailId);
    ArrayOfResponseMessagesType arrMail = p_mailResponse.ResponseMessages;
    ResponseMessageType[] responseMessages = arrMail.Items;
    foreach (ResponseMessageType respmsg in responseMessages)
    {
        if (respmsg.ResponseClass == ResponseClassType.Error)
        {
            throw new Exception("Error: " + respmsg.MessageText);
        }
        else if (respmsg.ResponseClass == ResponseClassType.Warning)
        {
            throw new Exception("Error: " + respmsg.MessageText);
        }
        //check to determine whether the response message is correct type 
        if (respmsg is ItemInfoResponseMessageType)
        {
            ItemInfoResponseMessageType createItemResp = 
                     (respmsg as ItemInfoResponseMessageType);
            ArrayOfRealItemsType aorit = createItemResp.Items;
            foreach (MessageType myitem in aorit.Items)
            {
                string  strSubject = myMessage.Subject;
                if (myMessage.From != null)
                {
                       string strFrom = myMessage.From.Item.Name;
                }
                StringBuilder objTo = new StringBuilder();

                if (myMessage.ToRecipients != null)
                {
                    //To be checked only for single recipient
                    foreach (EmailAddressType email in myMessage.ToRecipients)
                    {
                        objTo.Append(email.Name + "[" + email.EmailAddress + "];");


                    }
                }
                StringBuilder objCC = new StringBuilder();

                if (myMessage.CcRecipients != null)
                {
                    //To be checked only for single recipient
                    foreach (EmailAddressType email in myMessage.CcRecipients)
                    {
                        objCC.Append(email.Name + "[" + email.EmailAddress + "];");
                    }
                }
                objSignalDetailsRow.MailBody = myMessage.Body.Value;
            }
            //Similarly we can read other properties
        }

In the same way, we can read mails related to Calendaring, which will be explored in subsequent articles.

Setting Read Mails as Read

There is a property of type bool for MessageType called isRead. The first time a mail comes to the inbox, we show it in bold because it is not read yet, but when the mail is read, we need to set the property isRead to true so that the next time we show it as normal. After successfully reading a mail, we need to update this property to true. We have an API UpdateItem to update any existing item. The code to accomplish this is as shown:

public bool SetReadStatus(ItemIdType item)
{
    SetItemFieldType setField = new SetItemFieldType();
    PathToUnindexedFieldType path = new PathToUnindexedFieldType();

    MessageType message = new MessageType();
    message.IsRead = true;
    message.IsReadSpecified = true;
    setField.Item1 = message;
    path.FieldURI = UnindexedFieldURIType.messageIsRead;


    setField.Item = path;
    ItemChangeType[] updatedItems = new ItemChangeType[1];
    updatedItems[0] = new ItemChangeType();
    updatedItems[0].Updates = new ItemChangeDescriptionType[1];
    updatedItems[0].Updates[0] = setField;

    ItemChangeDescriptionType[] updates = new ItemChangeDescriptionType[1];
    updates[0] = new ItemChangeDescriptionType();
    updates[0].Item = path;

    updatedItems[0].Item = new ItemIdType();
    ((ItemIdType)updatedItems[0].Item).Id = item.Id;
    ((ItemIdType)updatedItems[0].Item).ChangeKey = item.ChangeKey;
    UpdateItemType request = new UpdateItemType();
    request.ItemChanges = updatedItems;
    request.ConflictResolution = ConflictResolutionType.AutoResolve;
    request.MessageDisposition = MessageDispositionType.SaveOnly;
    request.MessageDispositionSpecified = true;

    UpdateItemResponseType response = _esb.UpdateItem(request);

    if (response.ResponseMessages.Items[0].ResponseClass != 
                         ResponseClassType.Success)
        return false;
    else
        return true;
}

Extended Properties - Intro

Extended properties are very important for us when we make custom mail applications because, let's say, in a mail, we have default properties in the MessageType item, and if we want a new property, let's say, Classification, for our custom application, then we need to use an extended property.

Extended Properties - How to set them

We can create and set a new property as an extended property at the time of making an instance of the class (i.e., when setting the properties of that class).

MessageType p_objMessage=new p_objMessage();
p_objMessage.ExtendedProperty = new ExtendedPropertyType[1];

PathToExtendedFieldType pathClassification = new PathToExtendedFieldType();
pathClassification.DistinguishedPropertySetId =

DistinguishedPropertySetType.PublicStrings;
pathClassification.DistinguishedPropertySetIdSpecified = true;
pathClassification.PropertyName = "Classification";
pathClassification.PropertyType = MapiPropertyTypeType.String;
p_objMessage.ExtendedProperty[0] = new ExtendedPropertyType();
p_objMessage.ExtendedProperty[0].ExtendedFieldURI = pathClassification;
p_objMessage.ExtendedProperty[0].Item = msgRow.Classification;

Here, I am creating an extended property "Classification" for the MessageType object .This should be done at the time of setting the other properties of that object, after creating the object.

Extended Properties - How to read them

We have two scenarios here:

• Reading it at the time of searching\reading all the items for folders.
• Reading at the time of detailed reading.

For the first case: We first need to specify which property we want to read:

PathToExtendedFieldType pathClassification = new PathToExtendedFieldType();
pathClassification.DistinguishedPropertySetId = 
          DistinguishedPropertySetType.PublicStrings;
pathClassification.DistinguishedPropertySetIdSpecified = true;
pathClassification.PropertyName = "Clasification";
pathClassification.PropertyType = MapiPropertyTypeType.String;

But for using this, we first need to create an object of type ItemResponseShapeType as shown below and set the BaseShape property:

ItemResponseShapeType itemProperties = new ItemResponseShapeType();
// Use the Default shape for the response. 
itemProperties.BaseShape = DefaultShapeNamesType.Default;
itemProperties.AdditionalProperties = new BasePathToElementType[]
{ pathClassification };

And finally, we need to set this to the findRequest object, as:

findRequest.ItemShape = itemProperties;

For the second case: we first need to read the details by using GetItem; then again, we need to call the EWS API for all the extended properties because we can't do it in one go. The code is as shown:

public ExtendedPropertyType[] GetExtendedProperties(ItemIdType itemid)
{
    PathToExtendedFieldType pathClassification = new PathToExtendedFieldType();
    pathClassification.DistinguishedPropertySetId = 
       DistinguishedPropertySetType.PublicStrings;
    pathClassification.DistinguishedPropertySetIdSpecified = true;
    pathClassification.PropertyName = "Classification";
    pathClassification.PropertyType = MapiPropertyTypeType.String;


    GetItemType getExPropertiesRequest = new GetItemType();
    ItemIdType iiItemId = new ItemIdType();
    iiItemId = itemid;

    ItemResponseShapeType getResponseShape = new ItemResponseShapeType();
    getResponseShape.BaseShape = DefaultShapeNamesType.AllProperties;
    getResponseShape.IncludeMimeContent = true;
    getExPropertiesRequest.ItemShape = getResponseShape;

    getExPropertiesRequest.ItemShape.AdditionalProperties = 
                                     new BasePathToElementType[1];
    getExPropertiesRequest.ItemShape.AdditionalProperties[0] = pathClassification;


    getExPropertiesRequest.ItemIds = new ItemIdType[1];
    getExPropertiesRequest.ItemIds[0] = iiItemId;
    getExPropertiesRequest.ItemShape.BaseShape = DefaultShapeNamesType.AllProperties;

    GetItemResponseType giResponse = _esb.GetItem(getExPropertiesRequest);
    if (giResponse.ResponseMessages.Items[0].ResponseClass == ResponseClassType.Error)
    {
        throw new Exception("Error: " +
        giResponse.ResponseMessages.Items[0].MessageText);
    }
    else
    {
        ItemInfoResponseMessageType rmResponseMessage = 
             giResponse.ResponseMessages.Items[0] as ItemInfoResponseMessageType;

        if (rmResponseMessage.Items.Items[0].ExtendedProperty != null)
        {
            MessageType message = rmResponseMessage.Items.Items[0] as MessageType;
            return (message.ExtendedProperty);
        }
        else
        {
            return null;
        }
    }
}

Note: In this article, _esb is the object of ExchangeService is as in my earlier articles of the series.

I hope this series is useful for all those who are working on EWS. Suggestions are highly appreciated. In the next article, I'll start exploring the Calendaring provided by EWS.