/// <summary>
/// Executes this directive, if applicable.
/// </summary>
/// <param name="context">DB Context.</param>
/// <param name="text">SQL statement text</param>
/// <param name="directive">Source information.</param>
/// <param name="initState">Initialization state.</param>
/// <returns><c>true</c> if this processor can execute the current statement, otherwise <c>false</c></returns>
/// <exception cref="UnrecognizedStatementException">If this directive's <c>callback</c> returns <c>false</c></exception>
public bool TryExecute(CompositeProcessorContext context, string text, ScriptDirective directive, object initState)
{
if (directive.Name != DirectiveName)
{
return(false);
}
var statementName = ((InitializedState)initState).StatementName;
if (!callback(statementName, text))
{
throw new UnrecognizedStatementException(statementName, directive);
}
return(true);
}
/// <summary>
/// Executes this directive against the given context, if applicable.
/// </summary>
/// <param name="context">DB context</param>
/// <param name="text">SQL statement text</param>
/// <param name="directive">Source information</param>
/// <param name="initState">Initialization state</param>
/// <returns><see langword="true"/> if this processor is able to execute the given directive, otherwise <see langword="false" /></returns>
public bool TryExecute(CompositeProcessorContext context, string text, ScriptDirective directive, object initState)
{
if (directive.Name != DirectiveName && directive.Name != NegatedDirectiveName)
{
return(false);
}
var initData = (InitializedState)initState;
if (Eval(initData.PropertyName, initData.PropertyValue, initData.Negated))
{
var command = context.NewCommand();
command.CommandText = text;
command.ExecuteNonQuery();
}
return(true);
}
/// <summary>
/// Constructs an <see cref="UnrecognizedDirectiveException"/> with the given <see cref="ScriptDirective"/>.
/// </summary>
/// <param name="directive">The unrecognized script directive.</param>
public UnrecognizedDirectiveException(ScriptDirective directive) : base($"Unrecognized directive: {directive}")
{
Directive = directive;
}
/// <summary>
/// Construct a new <see cref="InvalidDirectiveException"/> with the given error <c>message</c>, and the offending
/// <see cref="ScriptDirective"/>.
/// </summary>
/// <param name="message">Message explaining why the direcitve or its configuration is invalid.</param>
/// <param name="directive">The invalid directive.</param>
public InvalidDirectiveException(string message, ScriptDirective directive) : base($"{message} ({directive.FileName}: {directive.LineNumber})")
{
Error = message;
Directive = directive;
}
/// <summary>
/// N/A
/// </summary>
/// <param name="context"></param>
/// <param name="directive"></param>
/// <param name="initState"></param>
/// <returns></returns>
/// <exception cref="NotImplementedException"></exception>
public DirectiveInitialization SetupDirective(CompositeProcessorContext context, ScriptDirective directive, object initState)
{
throw new NotImplementedException();
}
/// <summary>
/// Initializes this directive.
/// </summary>
/// <param name="context">DB context.</param>
/// <param name="directive">Directive to test.</param>
/// <returns><c>null</c> if not applicable, otherwise this directive's initialization state</returns>
/// <exception cref="InvalidDirectiveException">If the number of argments provided to this directive is not exactly <c>1</c></exception>
public DirectiveInitialization InitDirective(CompositeProcessorContext context, ScriptDirective directive)
{
if (directive.Name != DirectiveName)
{
return(null);
}
if (directive.Arguments.Count != 1)
{
throw new InvalidDirectiveException("Callback directive must have exactly 1 argument.", directive);
}
return(new DirectiveInitialization(new InitializedState(directive.Arguments[0])));
}
internal UnrecognizedStatementException(string statementName, ScriptDirective directive) : base($"Unrecognized statement name: {statementName}; Directive: {directive}")
{
StatementName = statementName;
Directive = directive;
}
/// <summary>
/// Initializes this directive as configured in the source script.
/// </summary>
/// <param name="context">DB context</param>
/// <param name="directive">Source information</param>
/// <returns>Initialization state if this processor can handle the given directive, otherwise <see langword="null" /></returns>
/// <exception cref="InvalidDirectiveException">If the provided argument count is less than 1 or greater than 2</exception>
public DirectiveInitialization InitDirective(CompositeProcessorContext context, ScriptDirective directive)
{
bool negated;
switch (directive.Name)
{
case DirectiveName:
negated = false;
break;
case NegatedDirectiveName:
negated = true;
break;
default:
return(null);
}
if (directive.Name != directive.Name)
{
return(null);
}
if (directive.Arguments.Count < 1)
{
throw new InvalidDirectiveException($"{directive.Name} must have at least 1 argument (property name).", directive);
}
if (directive.Arguments.Count > 2)
{
throw new InvalidDirectiveException($"{directive.Name} can have at most 2 arguments.", directive);
}
var propertyName = directive.Arguments[0];
var value = directive.Arguments.Count > 1 ? directive.Arguments[1] : null;
return(new DirectiveInitialization(new InitializedState(propertyName, value, negated)));
}
/// <summary>
/// Evaluates the given <see cref="ScriptDirective"/>.
/// </summary>
/// <remarks>
/// <para>If the given <c>directive</c> matches the <c>directiveName</c> or <c>negatedDirectiveName</c> given in the constructor,
/// the directive will be evaluated.</para>
///
/// <para>Properties replace directives have between 2 and 4 arguments:</para>
/// <list type="number">
/// <item>
/// <term><c>propertyName</c></term>
/// <description>Property name.</description>
/// </item>
/// <item>
/// <term><c>replaceValue</c> OR <c>propertyValue</c></term>
/// <description>If argument count is two, value to replace in statement text if <c>propertyName</c> is defined.
/// Otherwise, the value to evaluate <c>propertyName</c> against to determine replacement.</description>
/// </item>
/// <item>
/// <term><c>replaceValue</c></term>
/// <description>Value to replace in statement text if <c>propertyName</c> equals <c>propertyValue</c>, following
/// the semantics described in <see cref="PropertiesEvaluator.Eval"/>.</description>
/// </item>
/// <item>
/// <term><c>elseValue</c></term>
/// <description>Value to replace in statement text if the evaluation fails. Default is the empty string.</description>
/// </item>
/// </list>
/// </remarks>
/// <param name="context">Not used.</param>
/// <param name="directive"><see cref="ScriptDirective"/> to process.</param>
/// <returns>Appropriate <see cref="DirectiveInitialization"/> if <c>directive</c> is supported, otherwise <see langword="null" />.</returns>
public DirectiveInitialization InitDirective(CompositeProcessorContext context, ScriptDirective directive)
{
bool negated;
if (directive.Name == directiveName)
{
negated = false;
}
else if (directive.Name == negatedDirectiveName)
{
negated = true;
}
else
{
return(null);
}
if (directive.Arguments.Count < 2)
{
throw new InvalidDirectiveException($"{directiveName} must have at least 2 arguments (property name, replace value).", directive);
}
if (directive.Arguments.Count > 4)
{
throw new InvalidDirectiveException($"{directiveName} can have at most 4 arguments.", directive);
}
var propertyName = directive.Arguments[0];
var propertyValue = directive.Arguments.Count > 2 ? directive.Arguments[1] : null;
var replaceValue = directive.Arguments[directive.Arguments.Count > 2 ? 2 : 1];
var elseValue = directive.Arguments.Count > 3 ? directive.Arguments[3] : null;
if (deferRuntime)
{
return(new DirectiveInitialization(new InitializedState(propertyName, replaceValue, propertyValue, elseValue, negated), DirectiveInitializationAction.DeferSetup));
}
if (Eval(propertyName, propertyValue, negated))
{
return(new DirectiveInitialization(action: DirectiveInitializationAction.ReplaceText | DirectiveInitializationAction.NoStore, replacementText: replaceValue));
}
else
{
if (elseValue is not null)
{
return(new DirectiveInitialization(action: DirectiveInitializationAction.ReplaceText | DirectiveInitializationAction.NoStore, replacementText: elseValue));
}
else
{
return(new DirectiveInitialization(action: DirectiveInitializationAction.NoStore));
}
}
}
/// <summary>
/// Always returns <see langword="false"/> (does nothing). All necessary operations are performed in <see cref="InitDirective"/>
/// and <see cref="SetupDirective" />, if applicable.
/// </summary>
/// <param name="context"></param>
/// <param name="text"></param>
/// <param name="directive"></param>
/// <param name="initState"></param>
/// <returns><see langword="false"/></returns>
public bool TryExecute(CompositeProcessorContext context, string text, ScriptDirective directive, object initState)
{
return(false);
}
/// <summary>
/// Performs property <see cref="PropertiesEvaluator.Eval">evaluation</see> if <c>deferRuntime</c> was specified in the constructor.
/// </summary>
/// <param name="context">Not used.</param>
/// <param name="directive"><see cref="ScriptDirective"/> to process.</param>
/// <param name="initState">Processed directive argument information from <see cref="InitDirective"/>.</param>
/// <returns></returns>
public DirectiveInitialization SetupDirective(CompositeProcessorContext context, ScriptDirective directive, object initState)
{
if (!deferRuntime)
{
throw new NotImplementedException();
}
var initData = (InitializedState)initState;
if (Eval(initData.PropertyName, initData.PropertyValue, initData.Negated))
{
return(new DirectiveInitialization(action: DirectiveInitializationAction.ReplaceText, replacementText: initData.ReplaceValue));
}
else
{
if (initData.ElseValue is not null)
{
return(new DirectiveInitialization(action: DirectiveInitializationAction.ReplaceText, replacementText: initData.ElseValue));
}
else
{
return(new DirectiveInitialization());
}
}
}
