internal static ITableObject invokeGet(NrdoSingleGet get, FieldValueGetter getFieldValue)
{
if (get.Params.Count > 0 || get.ParamTables.Count > 0)
{
throw new ArgumentException("Get by " + get.Name + " is not eligible for use in nrdo.find.by since it has parameters that are not fields");
}
object[] args = new object[get.Fields.Count];
int i = 0;
foreach (NrdoFieldRef field in get.Fields)
{
if (!field.Table.IsSelf)
{
throw new ArgumentException("Get by " + get.Name + " is not eligible for use in nrdo.find.by since it uses fields not on the current table");
}
object value = getFieldValue(field.Field);
args[i++] = value;
if (value is Undefined)
{
return(null); // We skip attempts to call gets on Undefined values because the value is inherently unknown, the get couldn't succeed.
}
}
return(get.Call(args));
}
internal void Run(RecipeContext context)
{
DateTime now = DateTime.Now;
XmlElement recipeElement = doc.DocumentElement;
if (recipeElement.LocalName != "nrdo.recipe")
{
throw new InvalidDataException("Root element of a recipe must be <nrdo.recipe>");
}
foreach (XmlElement recordElement in elementChildren(recipeElement))
{
debug(recordElement, "Starting...");
if (recordElement.LocalName == "nrdo.id.changed")
{
context.ChangeNrdoId(recordElement.GetAttribute("from"), recordElement.GetAttribute("to"));
continue;
}
// Verify that the element corresponds to a table we know about
NrdoTable table = NrdoTable.GetTable(context.Lookup, recordElement.LocalName.Replace('.', ':'));
if (table == null)
{
throw new ArgumentException("No table called " + recordElement.LocalName + " could be found.");
}
// Scan for eligible references on the table, and break any corresponding values down into individual attributes
// of the :nrdoid.fieldname variety.
// NOTE: It's inefficient to just translate them into :nrdoid.fieldname rather than looking up the value at this
// point, because we have the object already and don't need to figure everything out again when we come to parse
// the attribute, but since we're storing the values into an XML attribute, we need something we can stringify.
// In future we could implement a cache on :nrdoid.fieldname strings, in which case we'd prepopulate that cache
// at this point. Recipe loading is not considered perf-critical though. Fortunately!
foreach (NrdoReference reference in table.References)
{
if (isEligibleReference(reference) && recordElement.HasAttribute(reference.Name))
{
string targetId = XmlUtil.GetAttr(recordElement, reference.Name);
RecipeRecord target = context.GetRecord(targetId);
recordElement.RemoveAttribute(reference.Name);
string raction = XmlUtil.GetAttr(recordElement, "nrdo.action");
if (target == null && raction != "none" && raction != "delete")
{
throw new ArgumentException("Could not find record with nrdo.id " + targetId + " in context (processing " + recordElement.LocalName + " " + XmlUtil.GetAttr(recordElement, "nrdo.id") + " " + raction + ")");
}
if (target != null)
{
if (target.TableName != reference.TargetTable.Name)
{
throw new ArgumentException("Target of reference " + reference.Name + " on " + table.Name + " is " + reference.TargetTable.Name + ", but nrdo.id " + targetId + " refers to a " + target.TableName);
}
foreach (NrdoJoin join in reference.Joins)
{
if (recordElement.HasAttribute(join.From.Field.Name))
{
throw new ArgumentException("Cannot specify field " + join.From.Field.Name + " at the same time as reference " + reference.Name + " which uses that field");
}
recordElement.SetAttribute(join.From.Field.Name, ":" + targetId + "." + join.To.Field.Name);
}
}
}
}
// Construct a key for looking up the value based on primary key
RecordKey key = new RecordKey(table, delegate(NrdoField field)
{
if (recordElement.HasAttribute(field.Name))
{
return(context.evaluate(field.Type, XmlUtil.GetAttr(recordElement, field.Name)));
}
else
{
return(Undefined.Value);
}
});
// Validate the nrdo.id attribute
// nrdo.id is required unless the pkey is not sequenced, AND all the
// pkey fields are specified (which is equivalent to key.IsDefined)
string nrdoId = null;
if (recordElement.HasAttribute("nrdo.id"))
{
nrdoId = XmlUtil.GetAttr(recordElement, "nrdo.id");
if (!Regex.IsMatch(nrdoId, "^[A-Za-z_][A-Za-z0-9_-]*$"))
{
throw new ArgumentException("Illegal nrdo.id value " + nrdoId);
}
}
else
{
if (table.IsPkeySequenced || !key.IsDefined)
{
throw new ArgumentException("Must specify nrdo.id attribute on " + table.Name);
}
}
// Verify that only attributes that are supposed to exist on the element actually do.
foreach (XmlAttribute attr in recordElement.Attributes)
{
switch (attr.Name)
{
case "nrdo.find.by":
case "nrdo.find.where":
if (!recordElement.HasAttribute("nrdo.id"))
{
throw new ArgumentException(attr.Name + " can only be specified if nrdo.id is present on " + table.Name);
}
if (key.IsDefined)
{
throw new ArgumentException(attr.Name + " cannot be specified if all primary keys are given on " + table.Name + " (" + recordElement.GetAttribute("nrdo.id") + ")");
}
break;
case "nrdo.id":
case "nrdo.exists":
case "nrdo.action":
// These are always legal. Nothing to see here. Move along.
break;
default:
if (table.GetField(attr.Name) == null)
{
throw new ArgumentException("No such field as " + attr.Name + " defined on " + table.Name);
}
break;
}
}
// Go and look up the record. If found, check its type matches the element, then clone it.
ITableObject data;
RecipeRecord record = context.GetRecord(nrdoId, key);
if (record != null)
{
if (record.TableName != table.Name)
{
throw new ArgumentException("nrdo.id " + nrdoId + " refers to a " + record.TableName + " record in the context, but is used on a " + table.Name + " record here.");
}
data = record.GetData();
record = record.Clone();
}
else
{
record = new RecipeRecord(context, table, nrdoId);
data = null;
if (recordElement.HasAttribute("nrdo.find.by") && recordElement.HasAttribute("nrdo.find.where"))
{
throw new ArgumentException("Cannot specify both nrdo.find.by and nrdo.find.where");
}
if (recordElement.HasAttribute("nrdo.find.where"))
{
throw new ArgumentException("nrdo.find.where is not implemented");
}
else if (recordElement.HasAttribute("nrdo.find.by"))
{
NrdoSingleGet get = null;
foreach (NrdoGet aGet in table.Gets)
{
if (aGet is NrdoSingleGet && aGet.Name == XmlUtil.GetAttr(recordElement, "nrdo.find.by"))
{
get = (NrdoSingleGet)aGet;
break;
}
}
if (get == null)
{
throw new ArgumentException("No single get by " + XmlUtil.GetAttr(recordElement, "nrdo.find.by") + " found on " + table.Name);
}
data = invokeGet(get, delegate(NrdoField field)
{
if (recordElement.HasAttribute(field.Name))
{
return(context.evaluate(field.NullableType, XmlUtil.GetAttr(recordElement, field.Name)));
}
else
{
return(null);
}
});
}
if (data != null)
{
foreach (NrdoField field in table.Fields)
{
record.PutField(new RecipeField(record, field.Name));
}
foreach (NrdoFieldRef field in table.PkeyGet.Fields)
{
record.PutField(new RecipeValueField(record, field.Field.Name, field.Field.Get(data)));
}
}
}
// Validate against the nrdo.exists attribute, if present.
if (recordElement.HasAttribute("nrdo.exists"))
{
string val = XmlUtil.GetAttr(recordElement, "nrdo.exists");
switch (val)
{
case "required":
if (data == null)
{
throw new ArgumentException("The record " + nrdoId + " is specified as 'required' in the recipe, but does not exist");
}
break;
case "permitted":
break;
case "error":
if (data != null)
{
throw new ArgumentException("The record " + nrdoId + " exists, but the recipe specifies that it must not");
}
break;
default:
throw new ArgumentException("Illegal value " + val + " for nrdo.exists attribute, legal values are required, permitted and error");
}
}
// Determine what needs to be done based on the nrdo.action attribute
string action = "update";
bool setFields = true;
bool overwriteFields = false;
if (recordElement.HasAttribute("nrdo.action"))
{
action = XmlUtil.GetAttr(recordElement, "nrdo.action");
}
switch (action)
{
case "none":
setFields = false;
break;
case "ensure":
if (data != null)
{
setFields = false;
}
// Otherwise equivalent to "update", which is the default case, nothing to do.
break;
case "update":
// Nothing to do; this is the default case.
break;
case "replace":
overwriteFields = true;
break;
case "delete":
if (data != null)
{
data.Delete();
context.RemoveRecord(record);
}
continue;
default:
throw new ArgumentException("Illegal value " + action + " for the nrdo.action attribute, legal values are none, ensure, update, replace and delete");
}
// If the record doesn't correspond to an existing item in the database, create it.
if (data == null)
{
// If the record wasn't found AND isn't being created, then we don't need to add it to the database or
// to the context.
if (!setFields)
{
continue;
}
List <object> ctorArgs = new List <object>();
foreach (NrdoField field in table.CtorParams)
{
object value = Undefined.Value;
if (recordElement.HasAttribute(field.Name))
{
value = context.evaluate(field.Type, XmlUtil.GetAttr(recordElement, field.Name));
}
if (value is Undefined)
{
value = defaultValue(field.Type, field.IsNullable);
}
if (value is Now)
{
ctorArgs.Add(now);
record.PutField(new RecipeField(record, field.Name));
}
else
{
ctorArgs.Add(value);
record.PutField(new RecipeValueField(record, field.Name, value));
}
}
data = table.Create(ctorArgs.ToArray());
}
// Set the appropriate fields based on what's already known in the context and whether overwriteFields is true
foreach (NrdoField field in table.Fields)
{
// Figure out whether this particular field should get set
bool setIt = false;
if (field.IsWritable && recordElement.HasAttribute(field.Name))
{
if (data.IsNew || overwriteFields)
{
setIt = setFields;
}
else
{
RecipeField rfield = record.GetField(field.Name);
if (rfield == null)
{
// Wish I could figure out something smarter to do here
setIt = false;
}
else if (rfield is RecipeValueField)
{
object value = ((RecipeValueField)rfield).Value;
if (object.Equals(field.Get(data), value))
{
setIt = setFields;
}
}
}
}
// Set the field
if (setIt)
{
object value = context.evaluate(field.Type, XmlUtil.GetAttr(recordElement, field.Name));
if (value is Now)
{
field.Set(data, now);
record.PutField(new RecipeField(record, field.Name));
}
else
{
field.Set(data, value);
record.PutField(new RecipeValueField(record, field.Name, value));
}
}
// Save the fact that we know the field, but not the value. But not if it's a readonly field,
// because that would have been set when the ctor was being processed.
else if (record.GetField(field.Name) == null)
{
// If the record was newly created, we know the value is the default for the type. Otherwise,
// we store that we just don't know the value.
if (data.IsNew)
{
if (field.IsWritable)
{
record.PutField(new RecipeValueField(record, field.Name, defaultValue(field.Type, field.IsNullable)));
}
else
{
// must either have been picked up by the constructor, or
// be the sequenced pkey and will be picked up below
}
}
else
{
record.PutField(new RecipeField(record, field.Name));
}
}
}
// Save the newly created object into the database and into the context
if (setFields)
{
data.Update();
}
// This covers sequenced pkeys and also covers the case where
// a DateTime field in the pkey was set to :now. If it's part of
// the pkey we can't change it (so storing the value is harmless)
// but we need to know it for future reference.
foreach (NrdoFieldRef pkeyField in table.PkeyGet.Fields)
{
record.PutField(new RecipeValueField(record, pkeyField.Field.Name, pkeyField.Field.Get(data)));
}
context.PutRecord(record);
debug(recordElement, "Finished");
}
}
