public static void BuildCommand(OracleCommand cmd, Func<string, OracleParameter> paramUpdater = null, Func<XElement, bool> customTagResolver = null)
{
XElement elemSql;
try
{
elemSql = XElement.Parse("<root>" + cmd.CommandText + "</root>", LoadOptions.PreserveWhitespace);
}
catch (XmlException ex)
{
var tokens = cmd.CommandText.Split(new[] {Environment.NewLine}, StringSplitOptions.None);
string msg;
if (ex.LineNumber >= 0 && ex.LineNumber < tokens.Length)
{
msg = tokens[ex.LineNumber - 1];
}
else
{
msg = string.Format("Line Number: {0}; LinePosition: {1}", ex.LineNumber, ex.LinePosition);
}
throw new ArgumentException(msg, "cmd.CommandText", ex);
}
var nav = new XPathEvaluator(p =>
{
OracleParameter param;
if (cmd.Parameters.Contains(p))
{
param = cmd.Parameters[p];
}
else
{
param = paramUpdater(p);
cmd.Parameters.Add(param);
}
return param.Value;
});
var toRemove = new HashSet<XElement>();
foreach (var elem in elemSql.Descendants())
{
Debug.Assert(elem != null, "elem != null");
if (toRemove.Contains(elem.Parent))
{
// Optimization.
// Do nothing because the parent has been removed and so this element is irrelevant
continue;
}
bool bKeep;
switch (elem.Name.LocalName)
{
case "if":
bKeep = EvaluateCondition(nav, elem);
break;
case "a":
//<a pre="(", sep=" OR ", post=")">mri.ia_id = :ia_id</a>
var matches = _regexParameters.Matches(elem.Value);
// Exception here if multiple parameters are found
string varName = matches.Cast<Match>().Select(p => p.Groups["paramName"].Value)
.Distinct().Single();
string condition = string.Format("${0}", varName);
bKeep = nav.Matches(condition);
if (bKeep)
{
bKeep = HandleArrayParamterXml(elem, varName, cmd);
}
break;
case "else":
// Keep the else only if all the previous else and if have been removed
bKeep = elem.ElementsBeforeSelf().Reverse()
.TakeUntil(p => p.Name.LocalName == "if")
.All(toRemove.Contains);
if (bKeep)
{
XAttribute attr = elem.Attribute("c");
if (attr != null)
{
bKeep = EvaluateCondition(nav, elem);
}
}
break;
default:
if (customTagResolver == null)
{
throw new NotSupportedException(elem.Name.LocalName);
}
bKeep = customTagResolver(elem);
break;
}
if (!bKeep)
{
toRemove.Add(elem);
}
}
toRemove.Remove();
cmd.CommandText = elemSql.Value;
string[] paramsUsed = _regexParameters.Matches(cmd.CommandText).Cast<Match>()
.Select(p => p.Groups["paramName"].Value)
.Distinct(StringComparer.InvariantCultureIgnoreCase)
.ToArray();
// Remove excess parameters. Note that we are performing case insensitive comparisons
string[] paramsUnused = cmd.Parameters.Cast<OracleParameter>()
.Select(p => p.ParameterName)
.Except(paramsUsed, StringComparer.InvariantCultureIgnoreCase).ToArray();
foreach (string name in paramsUnused)
{
cmd.Parameters.Remove(cmd.Parameters[name]);
}
// Create remaining used parameters
string[] paramsUncreated = paramsUsed.Except(cmd.Parameters.Cast<OracleParameter>().Select(p => p.ParameterName), StringComparer.InvariantCultureIgnoreCase).ToArray();
foreach (string name in paramsUncreated)
{
cmd.Parameters.Add(paramUpdater(name));
}
return;
}
private static bool EvaluateCondition(XPathEvaluator nav, XElement elem)
{
XAttribute attr = elem.Attribute("c");
string condition;
if (attr == null)
{
// Build the condition. This condition evaluates to true if all parameters found within the clause
// are not null
string[] paramsUsed = _regexParameters.Matches(elem.Value).Cast<Match>()
.Select(p => "$" + p.Groups["paramName"].Value)
.Distinct(StringComparer.InvariantCultureIgnoreCase)
.ToArray();
if (paramsUsed.Length == 0)
{
string msg = string.Format("Cannot infer condition. No parameter within {0}", elem.Value);
throw new Exception(msg);
}
condition = string.Join(" and ", paramsUsed);
}
else
{
condition = attr.Value;
}
bool bMatch = nav.Matches(condition);
return bMatch;
}
