/// <summary>
/// Checks that the content page does not contain invalid content.
/// </summary>
private List <Content> GetChildPageContents(DotvvmView childPage, List <ContentPlaceHolder> parentPlaceHolders)
{
// make sure that the body contains only whitespace and Content controls
var nonContentElements =
childPage.Children.Where(c => !((c is RawLiteral && ((RawLiteral)c).IsWhitespace) || (c is Content)));
if (nonContentElements.Any())
{
// show all error lines
var innerExceptions = nonContentElements.Select(s =>
new Exception($"Error occurred near line: {(s.GetValue(Internal.MarkupLineNumberProperty)?.ToString() ?? "")}.")).ToList(); // the message cannot be specifically to the line, because MarkupLineNumber shows the last character position which is a line under the error in some cases.
var corruptedFile = childPage.GetValue(Internal.MarkupFileNameProperty)?.ToString();
throw new AggregateException("If the page contains @masterpage directive, it can only contain white space and <dot:Content /> controls! \r\n"
+ (string.IsNullOrWhiteSpace(corruptedFile) ? "" : $"Corrupted file name: {corruptedFile}"), innerExceptions);
}
// make sure that the Content controls are not nested in other elements
var contents = childPage.GetAllDescendants().OfType <Content>()
.Where(c => !(bool)c.GetValue(Internal.IsMasterPageCompositionFinishedProperty))
.ToList();
if (contents.Any(c => c.Parent != childPage))
{
throw new Exception("The control <dot:Content /> cannot be placed inside any control!"); // TODO: exception handling
}
return(contents);
}
/// <summary>
/// Performs the master page nesting.
/// </summary>
private void PerformMasterPageComposition(DotvvmView childPage, DotvvmView masterPage)
{
if (!masterPage.ViewModelType.IsAssignableFrom(childPage.ViewModelType))
{
throw new DotvvmControlException(childPage, $"Master page requires viewModel of type '{masterPage.ViewModelType}' and it is not assignable from '{childPage.ViewModelType}'.");
}
// find content place holders
var placeHolders = GetMasterPageContentPlaceHolders(masterPage);
// find contents
var contents = GetChildPageContents(childPage, placeHolders);
// perform the composition
foreach (var content in contents)
{
// find the corresponding placeholder
var placeHolder = placeHolders.SingleOrDefault(p => p.ID == content.ContentPlaceHolderID);
if (placeHolder == null)
{
throw new DotvvmControlException(content, $"The placeholder with ID '{content.ContentPlaceHolderID}' was not found in the master page '{masterPage.GetValue(Internal.MarkupFileNameProperty)}'!");
}
// replace the contents
var contentPlaceHolder = new PlaceHolder();
contentPlaceHolder.SetDataContextType(content.Parent.GetDataContextType());
(content.Parent as DotvvmControl)?.Children.Remove(content);
placeHolder.Children.Clear();
placeHolder.Children.Add(contentPlaceHolder);
contentPlaceHolder.Children.Add(content);
content.SetValue(Internal.IsMasterPageCompositionFinishedProperty, true);
content.SetValue(DotvvmView.DirectivesProperty, childPage.Directives);
content.SetValue(Internal.MarkupFileNameProperty, childPage.GetValue(Internal.MarkupFileNameProperty));
}
// copy the directives from content page to the master page (except the @masterpage)
masterPage.ViewModelType = childPage.ViewModelType;
}