Get/Update a component field from event code

Question

I am working on event code 2011. I want to access a component attached to the page and update a field in that component. The component has two fields (Body and BodyImagePublish), both are text field. I know the code to read the component and acess its field but i don't know why the field shows null even if the component's [Body] field has the value(value is basically a xml)

The code is as below

      //Getting the component attached to this page
            page2 = (Tridion.ContentManager.CommunicationManagement.Page)publication.GetObject(uRI);
            //Getting the component as i want to read the [Body] field. Body has the xml  
            compToUpdate = page2.ComponentPresentations[0].Component;
            //I checked in the log generated by below statement that i am getting the tcm id of the component which has the values
            EventHelper.WriteEventToHTMLLog("comtoUpdate string: " + compToUpdate.ToString());
            //But the below condition does not satisfy, i opened the component and am sure that there is value in the body field
            if (compToUpdate.Content["Body"].Value != null)
            {
                //this condition does not  get satisfied which means that the component is null
            }
            //I also tried the below code from TOM.NET API chm file, but it throws error
            ItemFields contentFields = new ItemFields(compToUpdate.Content, compToUpdate.Schema);
            TextField myTextField = (TextField)contentFields["Body"];
            string myTextFieldValue = myTextField.Value;
            EventHelper.WriteEventToHTMLLog("comtoUpdate body field: " + myTextFieldValue);

Please help me.

Answer 1

answering the last comment to Nuno:

you can try below code, can adjust accordingly for checkout/checkin of the component. I havn't tested it so adjustments could be needed.

XDocument doc;
XElement xmlData;

string fieldName = "Body";
string fieldValue = "New Body Value";
doc = XDocument.Parse(compToUpdate.Content.OuterXml);
xmlData = doc.Root;
var newDoc = new XmlDocument();
XNamespace ns = xmlData.GetDefaultNamespace();
if (xmlData.Descendants(ns + fieldName).Count() > 0)
{
    xmlData.Descendants(ns + fieldName).SingleOrDefault().Value = fieldValue;

    newDoc.LoadXml(doc.ToString());
    compToUpdate.Content = newDoc.DocumentElement;
}

compToUpdate.Save();

EDIT by Nuno

Or you could acheve the same with the ItemFields class:

ItemFields content = new ItemFields(compToUpdate.Content, compToUpdate.Schema);
XhtmlField body = (XhtmlField) content["Body"];
body.Value = "some new value";
compToUpdate.Content = content.ToXml();

Since this is in an Event, I would not call Save(), and instead just modify the component in the Initiated phase and let Tridion do the save as normal.