How to add/insert a keyword into a component field using Core Service?

Question

I need to add a Keyword based on its Keyword title using the Core Service. Please help me which function of Core Service I can use along with some sample code if possible as well.

I have a Keyword field name called "familyKeyword" Here I just need to insert a Keyword to field name family keyword using Core Service.

string domainName = System.Configuration.ConfigurationSettings.AppSettings["domainName"];

        string userName = System.Configuration.ConfigurationSettings.AppSettings["userName"];

        string passowrd = System.Configuration.ConfigurationSettings.AppSettings["passowrd"];
        timestamp = DateTime.Now.ToString("dd:MM:yy h:mm:ss tt").Replace(":", "_").Replace(" ", "");

        string content = string.Empty;
        //string familyKeyword = "familyKeyword";
        //string keywordTitle = "Aromatics & Fibers";

        client = CoreServiceClientFactory.GetClient();

        var ComponentContent = client.Read("tcm:13-149625", new ReadOptions()) as ComponentData;
        content = ComponentContent.Content;

Answer 1

What you are looking for is to have the component tcm:13-149625 updated. Since you want the keyword Aromatics & Fibers inserted into the familyKeyword field, you would have to first read the keyword and update the component by inserting a new node which would insert the keyword title to the field.

// Parse the component's content into an XML.
var contentXml = XElement.Parse(component.Content);

// Read the "Aromatics & Fibers" keyword.
KeywordData keywordData = (KeywordData)client.Read("tcm:xx-xxx-1024", null);

// Create a new node for the "familyKeyword" field. 
XNamespace ns = "http://www.w3.org/1999/xlink";
XElement familyKeywordNode = new XElement(contentXml.GetDefaultNamespace() + "familyKeyword", 
    new XAttribute(XNamespace.Xmlns + "xlink", ns),
    new XAttribute(ns + "href", keywordData.Id),
    new XAttribute(ns + "title", keywordData.Title));
familyKeywordNode.Value = keywordData.Title;

// Add the  "familyKeyword" field into the content.
contentXml.Add(familyKeywordNode);

// Update the component.
component.Content = contentXml.ToString();
client.Update(component, null);

This stack exchange question How to update the component particular field node using core service about how to update components should also help you. Hope this helps!