// Implements the @bind(...) syntax
private bool TryAddBindExpression(RazorIRToken token)
{
const string bindExpressionStart = "bind(";
const string bindExpressionEnd = ")";
if (token.Content.StartsWith(bindExpressionStart) && token.Content.EndsWith(bindExpressionEnd))
{
// Extract "expr" from "bind(expr)"
var boundExpression = token.Content.Substring(
bindExpressionStart.Length,
token.Content.Length - bindExpressionStart.Length - bindExpressionEnd.Length);
// We can't work out the final binding expression code yet, because we don't yet know what
// type of element this is going onto (there might be a "type='checkbox'" or similar that
// appears *after* the @bind(...)). So just store the expression for later use.
_nextElementBoundExpression = MakeCSharpExpressionIRNode(token, boundExpression);
return(true);
}
return(false);
}
private static void AddIComponentRazorViewFactoryImplementation(ClassDeclarationIRNode classNode, RazorCodeDocument codeDoc)
{
// The Activator.CreateInstance feature that I added to the DNA runtime is very basic and doesn't
// actually invoke the default constructor of the type being created. It just allocates memory for
// the instance and returns it, without having run any constructor. This could be confusing if you
// put constructor logic (such as field initializers) in your Razor page, given that we instantiate
// it using Activator.CreateInstance.
// As a workaround (without actually adding constructor support to Activator.CreateInstance, which
// would be nontrivial), the Razor views privately implement an interface IComponentRazorViewFactory
// that can return new instances of their own type. We can then just call this with normal .NET code.
// This means we allocate memory for two instances of the view even though we're only using one,
// but it's not going to matter much as the first instance will just be released to GC immediately.
if (classNode.Interfaces == null)
{
classNode.Interfaces = new List <string>();
}
classNode.Interfaces.Add(typeof(IRazorComponentFactory).FullName);
var methodStatement = new CSharpStatementIRNode {
Parent = classNode, Source = null
};
classNode.Children.Add(methodStatement);
var model = codeDoc.Items["DetectedModel"];
string content = "";
string isPage = "";
string addItems = "";
if (model != null)
{
content = $@"Model = new {model}();";
}
if ((bool)codeDoc.Items["DetectedPage"])
{
isPage += "classNode.IsPage = true;";
}
if ((codeDoc.Items["DetectedPageMatches"]) != null)
{
var list = (List <string>)codeDoc.Items["DetectedPageMatches"];
addItems += "List<string> list = new List<string>();";
foreach (var item in list)
{
addItems += $"\r\n list.Add(\"{item}\");";
}
addItems += "\r\n Items = list;";
}
var razorToken = new RazorIRToken
{
Kind = RazorIRToken.TokenKind.CSharp,
Parent = classNode,
Content = $@"
{typeof(RazorComponent).FullName} {typeof(IRazorComponentFactory).FullName}.{nameof(IRazorComponentFactory.Instantiate)}()
{{
{content}
var classNode = new {classNode.Name}();
{isPage}
{addItems}
return classNode;
}}"
};
methodStatement.Children.Add(razorToken);
}
