SharePoint web services: test if file exists - web-services

Question

I'm using SharePoint web services in C#. I have my code working to check files and check them out using the Lists web service. I need to test to see if a file exists; I can find lots of examples for doing this using the object model API, but I can't seem to find a straightforward way of doing this using web services.

Answer 1

Try the Lists.GetListItems with a suitable CAML query.
A CAML query like
<Query><Where><Eq><FieldRef Name="FileLeafRef" /><Value Type="Text">Filename.rtf</Value></Eq></Where></Query>
should work; the field 'FileLeafRef' is where the filename is stored.

Answer 2

This code may do, it's a little rough, but demonstrates how to get a list of files based on the title.
public static bool PageExists(string listName, string webPath, string pageTitle)
{
string pageId = "";
IntranetLists.Lists lists = new IntranetLists.Lists();
lists.UseDefaultCredentials = true;
lists.Url = webPath + "/_vti_bin/lists.asmx";
XmlDocument doc = new XmlDocument();
doc.LoadXml("<Document><Query><Where><Contains><FieldRef Name=\"Title\" /><Value Type=\"Text\">" + pageTitle + "</Value></Contains></Where></Query><ViewFields /><QueryOptions /></Document>");
XmlNode listQuery = doc.SelectSingleNode("//Query");
XmlNode listViewFields = doc.SelectSingleNode("//ViewFields");
XmlNode listQueryOptions = doc.SelectSingleNode("//QueryOptions");
Guid g = GetWebID(webPath);
XmlNode items = lists.GetListItems(listName, string.Empty, listQuery, listViewFields, string.Empty, listQueryOptions, g.ToString());
}
return items.Count > 0;
}
public static XmlNodeList XpathQuery(XmlNode xmlToQuery, string xPathQuery)
{
XmlDocument doc = new XmlDocument();
doc.LoadXml(xmlToQuery.OuterXml);
XmlNamespaceManager mg = new XmlNamespaceManager(doc.NameTable);
mg.AddNamespace("sp", "http://schemas.microsoft.com/sharepoint/soap/");
mg.AddNamespace("z", "#RowsetSchema");
mg.AddNamespace("rs", "urn:schemas-microsoft-com:rowset");
mg.AddNamespace("y", "http://schemas.microsoft.com/sharepoint/soap/ois");
mg.AddNamespace("w", "http://schemas.microsoft.com/WebPart/v2");
mg.AddNamespace("d", "http://schemas.microsoft.com/sharepoint/soap/directory");
return doc.SelectNodes(xPathQuery, mg);
}

Answer 3

I also had similiar problems with this.
I have tried the following FieldRefs without success: "Name", "FileLeafRef" and "LinkFilenameNoMenu".
The post located at http://www.johanolivier.blogspot.com details what I had to do to get it working.