/// <summary> Lists all of the identifiers within a particular OAI-PMH set </summary>
/// <param name="Output"> Stream to which to write the text for this main writer </param>
/// <param name="SetCode"> Code for the OAI-PMH set </param>
/// <param name="From"> Date from which to return all the identifiers </param>
/// <param name="Until"> Date to which to return all the identifiers </param>
/// <param name="MetadataPrefix"> Prefix of the metadata fomat to return the identifier information</param>
/// <param name="ResumptionToken"> Resumption token from the original query string, if one was provided </param>
protected internal void ListIdentifiers(TextWriter Output, string SetCode, string From, string Until, string MetadataPrefix, string ResumptionToken)
{
// Set the default dates and page first
DateTime from_date = new DateTime(1900, 1, 1);
DateTime until_date = DateTime.Now.AddDays(1);
int current_page = 1;
// Start to build the request XML
StringBuilder request = new StringBuilder();
// If there is a resumption token, that should be used to pull all information
if (ResumptionToken.Length > 0)
{
// Add to the request
request.Append("resumptionToken=\"" + ResumptionToken + "\" ");
// Try to get the MetadataPrefix from the token
if (ResumptionToken.IndexOf(":") < 0)
{
Write_Error(Output, "resumptionToken=\"" + ResumptionToken + "\" verb=\"ListRecords\"", "badResumptionToken", "no metadata specified in resumption token:" + ResumptionToken);
return;
}
// Compute the state from the token
try
{
MetadataPrefix = ResumptionToken.Substring(ResumptionToken.IndexOf(":") + 1);
string modifiedToken = ResumptionToken.Substring(0, ResumptionToken.IndexOf(":"));
string page_string = modifiedToken.Substring(0, 6);
SetCode = modifiedToken.Substring(6 + oai_repository_identifier.Length);
// Try to parse the page and dates now
if (!Int32.TryParse(page_string, out current_page))
{
Write_Error(Output, "resumptionToken=\"" + ResumptionToken + "\" verb=\"ListRecords\"", "badResumptionToken", "no resumeAfter in resumptionToken:" + ResumptionToken);
return;
}
// Was there a from and until date included in the token?
if (SetCode.IndexOf(".") > 0)
{
int period_index = SetCode.IndexOf(".");
string from_string = SetCode.Substring(period_index + 1, 8);
string until_string = SetCode.Substring(period_index + 9, 8);
SetCode = SetCode.Substring(0, period_index);
// Before we can parse those dates, we need to format a bit for the .NET framework
from_string = from_string.Substring(4, 2) + "/" + from_string.Substring(6) + "/" + from_string.Substring(0, 4);
until_string = until_string.Substring(4, 2) + "/" + until_string.Substring(6) + "/" + until_string.Substring(0, 4);
// Try to parse the dates now
if ((!DateTime.TryParse(from_string, out from_date)) || (!DateTime.TryParse(until_string, out until_date)))
{
Write_Error(Output, "resumptionToken=\"" + ResumptionToken + "\" verb=\"ListRecords\"", "badResumptionToken", "no resumeAfter in resumptionToken:" + ResumptionToken);
return;
}
}
}
catch
{
Write_Error(Output, "resumptionToken=\"" + ResumptionToken + "\" verb=\"ListIdentifiers\"", "badResumptionToken", "no resumeAfter in resumptionToken:" + ResumptionToken);
return;
}
}
else
{
// Add to the request
if (From.Length > 0)
{
request.Append("from=\"" + From + "\" ");
}
request.Append("metadataPrefix=\"" + MetadataPrefix + "\" ");
if (SetCode.Length > 0)
{
request.Append("set=\"" + SetCode + "\" ");
}
if (Until.Length > 0)
{
request.Append("until=\"" + Until + "\" ");
}
// Check the format of FROM and UNTIL, if they are provided
const string REGEX_MATCH_STRING = "([0-9]{4})(-([0-9]{2})(-([0-9]{2})))";
if (From.Length > 0)
{
if ((From.Length != 10) || (!Regex.Match(From, REGEX_MATCH_STRING).Success) || (!DateTime.TryParse(From, out from_date)))
{
Write_Error(Output, "verb=\"\"", "badArgument", "bad OAI date format:" + From);
return;
}
}
if (Until.Length > 0)
{
if ((Until.Length != 10) || (!Regex.Match(Until, REGEX_MATCH_STRING).Success) || (!DateTime.TryParse(Until, out until_date)))
{
Write_Error(Output, "verb=\"\"", "badArgument", "bad OAI date format:" + Until);
return;
}
}
}
// Make sure both the identifier and metadata have data
if (MetadataPrefix.Length == 0)
{
Write_Error(Output, "verb=\"\"", "badArgument", "metadataPrefix required argument is missing.");
return;
}
// Finish the request echo portion
request.Append("verb=\"ListIdentifiers\"");
// Metadata prefix must be in list of acceptable
if (!metadataPrefixes.Contains(MetadataPrefix))
{
Write_Error(Output, request.ToString(), "cannotDisseminateFormat", MetadataPrefix + " is not supported by this repository.");
return;
}
// Get the records
List <OAI_Record> results = SobekCM_Database.Get_OAI_Data(SetCode, MetadataPrefix, from_date, until_date, IDENTIFIERS_PER_PAGE, current_page, false);
if (results.Count == 0)
{
Write_Error(Output, request.ToString(), "noRecordsMatch", "There are no records matching the criteria indicated by this request's arguments.");
}
else
{
// Determine if a resumption token should be submitted after this. This is easily
// done since the database will attempt to return one additional record, if more records
// exist
bool more_records = false;
if (results.Count > IDENTIFIERS_PER_PAGE)
{
more_records = true;
results.RemoveAt(results.Count - 1);
}
// Write the list of records/identifiers
Write_OAI_ListRecords(SetCode, from_date, until_date, ResumptionToken, request.ToString(), true, current_page, more_records, MetadataPrefix, results, Output);
}
}
