Friday, September 02, 2016

How to Like\Unlike an Item using EWS in Exchange Online

Likes and Mentions are a new feature in Exchange Online (in OWA) that was introduced late last year in First Release for Office365. With the focused Inbox now being rolled out to replace clutter these are some of the new social user curation type features that could change the user experience (hopefully for the better) in the coming years. While none of these features are new to those people using other Social platforms like facebook, twitter etc they do offer a world of new possibilities to those that have a little imagination.

In this post I'm going to look at how you can Like an item using Exchange Web Services eg

Currently there is no real documentation on the use of Likes in any API or how they are delivered in Exchange Online so care should be taken as this may mean the feature is subject to change in any of the future service updates.

Versioning your Requests

To use likes fully you need to make sure you version your EWS requests (which involves setting the ServerRequestVersion in the SOAP header) to V2015_10_05 or higher.  The Like information is returned by Exchange as a Strongly Type property in EWS (LikeType). If you look at a Response that includes the Like information in the SOAP response you should see both Like and LikePreview returned eg

      <t:Name>Glen Scales</t:Name>
    <t:Name>Glen Scales</t:Name>

If you have the latest proxy objects from the Exchange Online WSDL then you should see the Likes and LikePreview property collections in the ItemType Class. In the latest EWS Managed API from github only the Likes class is currently available.

Liking an Item (Unsupported)

The EWS LikeItem operation currently has no definition in the Services.WSDL so liking an Item via EWS is currently unsupported. However you can still use the operation as long as you construct the request using Raw SOAP message eg a request to like or unlike and item using EWS look like

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap=""
    <t:RequestServerVersion Version="V2015_10_05"/>
  <soap:Body xmlns="">
      <ItemId Id="AAM.." ChangeKey="CQA.."/>

As this is an unsupported operation if you do something like try to like the same item twice you will get a 500 error rather then a nice SOAP based error response. I've put together a scrip that allows you to search for an Item via subject and like or unlike it using EWS. I've put this up on GitHub here