/// <summary>
/// Invokes the rule on the specified <see cref="ModelInstance"/> as a result
/// of the specified triggering <see cref="ModelEvent"/>
/// </summary>
/// <param name="root"></param>
/// <param name="modelEvent"></param>
internal void Invoke(ModelInstance root, ModelEvent modelEvent)
{
try
{
if (BeforeInvoke != null)
{
BeforeInvoke(this, EventArgs.Empty);
}
ModelEventScope.Perform(() => OnInvoke(root, modelEvent));
}
finally
{
if (AfterInvoke != null)
{
AfterInvoke(this, EventArgs.Empty);
}
}
}
/// <summary>
/// Generates a script tag to embed a model including instance data into a server-rendered view.
/// Supports initial customization of the model via an initialization delegate.
/// </summary>
/// <param name="query"></param>
/// <param name="init"></param>
/// <returns></returns>
static void Model(TextWriter writer, object query, Delegate init)
{
// Raise the begin model event
if (BeginModel != null)
{
BeginModel(query, EventArgs.Empty);
}
// Get the roots for each query
var roots = new List <KeyValuePair <string, ServiceRequest.Query> >();
foreach (var prop in query.GetType().GetProperties())
{
// Get the value of the model property
var m = prop.GetValue(query, null);
if (m == null)
{
continue;
}
// Convert the value into a query, if necessary
var q = m as ServiceRequest.Query ?? Query(m);
if (q != null)
{
q.LoadRoots(null);
roots.Add(new KeyValuePair <string, ServiceRequest.Query>(prop.Name, q));
}
}
// Create the request object
ServiceRequest request = new ServiceRequest(roots.Select(r => r.Value).ToArray());
// Synthesize init new changes for new query roots
ModelTransaction initChanges = (ModelTransaction)request.Queries
.SelectMany(q => q.Roots)
.Where(i => i.IsNew)
.Select(i => new ModelInitEvent.InitNew(i))
.Cast <ModelEvent>()
.ToList();
// Perform the initialization action, if specified
if (init != null)
{
// Determine matching parameters
var parameters = new object[init.Method.GetParameters().Length];
foreach (var p in init.Method.GetParameters())
{
foreach (var root in roots)
{
if (p.Name.Equals(root.Key, StringComparison.InvariantCultureIgnoreCase))
{
// List parameter
if (p.ParameterType.IsArray)
{
parameters[p.Position] = root.Value.Roots.Select(r => r.Instance).ToArray();
}
// Instance parameter
else
{
parameters[p.Position] = root.Value.Roots.Select(r => r.Instance).FirstOrDefault();
}
break;
}
}
// Throw an exception if the model property value cannot be cast to the corresponding initialization parameter
if (parameters[p.Position] != null && !p.ParameterType.IsAssignableFrom(parameters[p.Position].GetType()))
{
throw new ArgumentException(String.Format("The model property '{0}' cannot be converted into the initialization parameter type of '{1}'.", p.Name, p.ParameterType.FullName));
}
// Throw an exception if a valid model parameter could not be found to pass to the initialization delegate
if (parameters[p.Position] == null && query.GetType().GetProperty(p.Name, BindingFlags.Public | BindingFlags.IgnoreCase | BindingFlags.Instance) == null)
{
throw new ArgumentException(String.Format("A model property could not be found to pass to the initialization parameter '{0}'.", p.Name));
}
}
// Perform initialization while capturing changes
initChanges.Record(() =>
{
// Prevent property change rules from running until after initialization
ModelEventScope.Perform(() => init.DynamicInvoke(parameters));
});
}
// Invoke the request queries
ServiceResponse response = request.Invoke(initChanges);
response.Model = roots.ToDictionary(r => r.Key, r => r.Value);
foreach (var q in response.Model.Values)
{
q.ReducePaths();
}
// Track the current model roots to support server template rendering
foreach (var root in response.Model)
{
Templates.Page.Current.Model[root.Key] = root.Value.IsList ? (object)root.Value.Roots : (root.Value.Roots.Length == 1 ?root.Value.Roots[0] : null);
}
// Write the model embed script to the writer
writer.Write("<script type=\"text/javascript\">$exoweb(");
JsonUtility.Serialize(writer, response);
writer.Write(");</script>");
// Raise the end model event
if (EndModel != null)
{
EndModel(query, EventArgs.Empty);
}
}
