{"<user xmlns=''> was not expected.} Deserializing Twitter XML

Question

I'm pulling in the XML from Twitter via OAuth.

I'm doing a request to http://twitter.com/account/verify_credentials.xml, which returns the following XML:

<?xml version="1.0" encoding="UTF-8"?>
<user>
  <id>16434938</id>
  <name>Lloyd Sparkes</name>
  <screen_name>lloydsparkes</screen_name>
  <location>Hockley, Essex, UK</location>
  <description>Student</description>
  <profile_image_url>http://a3.twimg.com/profile_images/351849613/twitterProfilePhoto_normal.jpg</profile_image_url>
  <url>http://www.lloydsparkes.co.uk</url>
  <protected>false</protected>
  <followers_count>115</followers_count>
  <profile_background_color>9fdaf4</profile_background_color>
  <profile_text_color>000000</profile_text_color>
  <profile_link_color>220f7b</profile_link_color>
  <profile_sidebar_fill_color>FFF7CC</profile_sidebar_fill_color>
  <profile_sidebar_border_color>F2E195</profile_sidebar_border_color>
  <friends_count>87</friends_count>
  <created_at>Wed Sep 24 14:26:09 +0000 2008</created_at>
  <favourites_count>0</favourites_count>
  <utc_offset>0</utc_offset>
  <time_zone>London</time_zone>
  <profile_background_image_url>http://s.twimg.com/a/1255366924/images/themes/theme12/bg.gif</profile_background_image_url>
  <profile_background_tile>false</profile_background_tile>
  <statuses_count>1965</statuses_count>
  <notifications>false</notifications>
  <geo_enabled>false</geo_enabled>
  <verified>false</verified>
  <following>false</following>
  <status>
    <created_at>Mon Oct 12 19:23:47 +0000 2009</created_at>
    <id>4815268670</id>
    <text>&#187; @alexmuller your kidding? it should all be &quot;black tie&quot; dress code</text>
    <source>&lt;a href=&quot;http://code.google.com/p/wittytwitter/&quot; rel=&quot;nofollow&quot;&gt;Witty&lt;/a&gt;</source>
    <truncated>false</truncated>
    <in_reply_to_status_id>4815131457</in_reply_to_status_id>
    <in_reply_to_user_id>8645442</in_reply_to_user_id>
    <favorited>false</favorited>
    <in_reply_to_screen_name>alexmuller</in_reply_to_screen_name>
    <geo/>
  </status>
</user>

I am using the following code to deserialize:

    public User VerifyCredentials()
    {
        string url = "http://twitter.com/account/verify_credentials.xml";
        string xml = _oauth.oAuthWebRequestAsString(oAuthTwitter.Method.GET, url, null);

        XmlSerializer xs = new XmlSerializer(typeof(User),"");

        MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(xml));

        return (User)xs.Deserialize(ms);
    }

And I have the following for my User class:

 [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
public partial class User
{

    [XmlElement(ElementName = "id")]       
    public long Id { get; set; }

    [XmlElement(ElementName = "name")] 
    public string Name { get; set; }

    [XmlElement(ElementName = "screen_name")]       
    public string ScreenName { get; set; }

    [XmlElement(ElementName = "location")]       
    public string Location { get; set; }

    [XmlElement(ElementName = "description")]      
    public string Description { get; set; }

    [XmlElement(ElementName = "profile_image_url")]      
    public string ProfileImageUrl { get; set; }

    [XmlElement(ElementName = "url")]       
    public string Url { get; set; }

    [XmlElement(ElementName = "protected")]      
    public bool Protected { get; set; }

    [XmlElement(ElementName = "followers_count")]      
    public int FollowerCount { get; set; }

    [XmlElement(ElementName = "profile_background_color")]       
    public string ProfileBackgroundColor { get; set; }

    [XmlElement(ElementName = "profile_text_color")]       
    public string ProfileTextColor { get; set; }

    [XmlElement(ElementName = "profile_link_color")]       
    public string ProfileLinkColor { get; set; }

    [XmlElement(ElementName = "profile_sidebar_fill_color")]       
    public string ProfileSidebarFillColor { get; set; }

    [XmlElement(ElementName = "profile_sidebar_border_color")]      
    public string ProfileSidebarBorderColor { get; set; }

    [XmlElement(ElementName = "friends_count")]     
    public int FriendsCount { get; set; }

    [XmlElement(ElementName = "created_at")]     
    public string CreatedAt { get; set; }

    [XmlElement(ElementName = "favourties_count")]      
    public int FavouritesCount { get; set; }

    [XmlElement(ElementName = "utc_offset")]      
    public int UtcOffset { get; set; }

    [XmlElement(ElementName = "time_zone")]       
    public string Timezone { get; set; }

    [XmlElement(ElementName = "profile_background_image_url")]        
    public string ProfileBackgroundImageUrl { get; set; }

    [XmlElement(ElementName = "profile_background_tile")]        
    public bool ProfileBackgroundTile { get; set; }

    [XmlElement(ElementName = "statuese_count")]        
    public int StatusesCount { get; set; }

    [XmlElement(ElementName = "notifications")]       
    public string Notifications { get; set; }

    [XmlElement(ElementName = "geo_enabled")]       
    public bool GeoEnabled { get; set; }

    [XmlElement(ElementName = "Verified")]        
    public bool Verified { get; set; }

    [XmlElement(ElementName = "following")]
    public string Following { get; set; }

    [XmlElement(ElementName = "status", IsNullable=true)]
    public Status CurrentStatus { get; set; }

}

But when it's deserializing the above XML the application throws the following:

$exception {"There is an error in XML document (2, 2)."} System.Exception {System.InvalidOperationException}

InnerException {"<user xmlns=''> was not expected."} System.Exception {System.InvalidOperationException}

Now I have searched around and the best solution I can find is to add blank namespaces to the serializer when you serialize the content, but i'm not serializing it so I can't.

I also have some code for receiving Statuses, which works fine.

So can someone explain to me why the error is happening? As well as a possible solution?

Answer 1

Either decorate your root entity with the XmlRoot attribute which will be used at compile time.

[XmlRoot(Namespace = "www.contoso.com", ElementName = "MyGroupName", DataType = "string", IsNullable=true)]

Or specify the root attribute when de serializing at runtime.

XmlRootAttribute xRoot = new XmlRootAttribute();
xRoot.ElementName = "user";
// xRoot.Namespace = "http://www.cpandl.com";
xRoot.IsNullable = true;

XmlSerializer xs = new XmlSerializer(typeof(User),xRoot);