/// <summary>
/// Given parsed untyped JSON in diff format, construct a PersistonDiff
/// </summary>
public static PersistonDiff FromDiff(DataDictionary dbdef, JObject jroot)
{
var datonKey = DatonKey.Parse(jroot.Value <string>("key"));
var datondef = dbdef.FindDef(datonKey);
var diff = new PersistonDiff(datondef, datonKey, jroot.Value <string>("version"));
ReadJsonDiffRowArray(jroot, datondef.MainTableDef, diff.MainTable);
//existing single-main-row diffs might not include the primary key in the main row, so add it here
if (!datondef.MultipleMainRows)
{
var mainDiffRow = diff.MainTable.First();
if (!mainDiffRow.Columns.ContainsKey(datondef.MainTableDef.PrimaryKeyColName))
{
var pkColdef = datondef.MainTableDef.FindCol(datondef.MainTableDef.PrimaryKeyColName);
var pk = Utils.ChangeType(((PersistonKey)datonKey).PrimaryKey, pkColdef.CSType);
mainDiffRow.Columns[datondef.MainTableDef.PrimaryKeyColName] = pk;
}
}
return(diff);
}
/// <summary>
/// Return readable strings describing any disallowed writes for this user
/// </summary>
/// <param name="pristineDaton">null for new unsaved persistons, else the pristine version being edited</param>
public IEnumerable <string> GetDisallowedWrites(Daton pristineDaton, DatonDef datondef, PersistonDiff diff)
{
var errors = new List <string>();
FindDisallowedWrites(errors, pristineDaton, datondef.MainTableDef, diff.MainTable);
return(errors);
}
/// <summary>
/// Save persiston to database
/// </summary>
/// <param name="pristineDaton">null or the version before the diff was applied</param>
/// <param name="modifiedDaton">the validated final version</param>
/// <param name="diff">the difference between pristine and modified, which is what this method inspects to make the changes</param>
public virtual async Task Save(IDbConnection db, IUser user, Persiston pristineDaton, Persiston modifiedDaton, PersistonDiff diff)
{
//called for each row in traversal; return true to recurse over children
async Task <(object, bool)> rowCallback(RowChangingData cdata)
{
if (cdata.DiffRow.Kind == DiffKind.DeletedRow)
{
await DeleteRowWithCascade(db, cdata.TableDef, cdata.PristineRow);
return(null, false); //don't recur to children of deleted row
}
object newpk = await InsertUpdateRow(db, cdata);
return(newpk, true);
}
var tdata = new TraversalData
{
ParentKey = null,
TableDef = diff.DatonDef.MainTableDef,
DiffRowList = diff.MainTable,
PristineList = null,
ModifiedList = null,
ProcessRowF = rowCallback
};
if (diff.DatonDef.MultipleMainRows)
{
var mainListField = diff.DatonDef.Type.GetField(tdata.TableDef.Name);
tdata.PristineList = mainListField.GetValue(pristineDaton) as IList;
tdata.ModifiedList = mainListField.GetValue(modifiedDaton) as IList;
await TraverseDiffList(tdata, null, null);
}
else
{
await TraverseDiffList(tdata, pristineDaton, modifiedDaton);
}
}
