/// <summary>
/// Writes text iff the property contains hard-coded value OR
/// writes knockout text binding iff the property contains binding
/// </summary>
/// <param name="writer">HTML output writer</param>
/// <param name="obj">Dotvvm control which contains the <see cref="DotvvmProperty"/> with value to be written</param>
/// <param name="property">Value of this property will be written</param>
/// <param name="wrapperTag">Name of wrapper tag, null => knockout binding comment</param>
public static void WriteTextOrBinding(this IHtmlWriter writer, DotvvmBindableObject obj, DotvvmProperty property, string wrapperTag = null)
{
var valueBinding = obj.GetValueBinding(property);
if (valueBinding != null)
{
if (wrapperTag == null)
{
writer.WriteKnockoutDataBindComment("text", valueBinding.GetKnockoutBindingExpression(obj));
writer.WriteKnockoutDataBindEndComment();
}
else
{
writer.AddKnockoutDataBind("text", valueBinding.GetKnockoutBindingExpression(obj));
writer.RenderBeginTag(wrapperTag);
writer.RenderEndTag();
}
}
else
{
if (wrapperTag != null)
{
writer.RenderBeginTag(wrapperTag);
}
writer.WriteText(obj.GetValue(property).ToString());
if (wrapperTag != null)
{
writer.RenderEndTag();
}
}
}
public static void WriteKnockoutDataBindComment(this IHtmlWriter writer, string name, DotvvmBindableObject control, DotvvmProperty property)
{
var binding = control.GetValueBinding(property);
if (binding is null)
{
throw new DotvvmControlException(control, $"A value binding expression was expected in property {property}.");
}
writer.WriteKnockoutDataBindComment(name, binding.GetKnockoutBindingExpression(control));
}
/// <summary>
/// Returns Javascript expression that represents the property value (even if the property contains hardcoded value)
/// </summary>
public static string GetKnockoutBindingExpression(this DotvvmBindableObject obj, DotvvmProperty property)
{
var binding = obj.GetValueBinding(property);
if (binding != null)
{
return(binding.GetKnockoutBindingExpression(obj));
}
return(JsonConvert.SerializeObject(obj.GetValue(property), DefaultViewModelSerializer.CreateDefaultSettings()));
}
/// <summary>
/// Returns Javascript expression that represents the property value (even if the property contains hardcoded value)
/// </summary>
public static string GetKnockoutBindingExpression(this DotvvmBindableObject obj, DotvvmProperty property)
{
var binding = obj.GetValueBinding(property);
if (binding != null)
{
return(binding.GetKnockoutBindingExpression());
}
return(JsonConvert.SerializeObject(obj.GetValue(property)));
}
/// <summary>
/// Gets the validation target expression.
/// </summary>
public static string GetValidationTargetExpression(DotvvmBindableObject control)
{
if (!(bool)control.GetValue(Validation.EnabledProperty))
{
return(null);
}
return(control.GetValueBinding(Validation.TargetProperty)?.GetKnockoutBindingExpression(control) ??
RootValidationTargetExpression);
}
internal IEnumerable <IValueBinding> GetDataContextHierarchy()
{
var bindings = new List <IValueBinding>();
DotvvmBindableObject current = this;
do
{
var binding = current.GetValueBinding(DataContextProperty, false);
if (binding != null)
{
bindings.Add(binding);
}
current = current.Parent;
}while (current != null);
bindings.Reverse();
return(bindings);
}
public static void AddKnockoutDataBind(this IHtmlWriter writer, string name, DotvvmBindableObject control, DotvvmProperty property, Action?nullBindingAction = null,
string?valueUpdate = null, bool renderEvenInServerRenderingMode = false, bool setValueBack = false)
{
var expression = control.GetValueBinding(property);
if (expression != null && (!control.RenderOnServer || renderEvenInServerRenderingMode))
{
writer.AddKnockoutDataBind(name, expression.GetKnockoutBindingExpression(control));
if (valueUpdate != null)
{
writer.AddKnockoutDataBind("valueUpdate", $"'{valueUpdate}'");
}
}
else
{
nullBindingAction?.Invoke();
if (setValueBack && expression != null)
{
control.SetValue(property, expression.Evaluate(control));
}
}
}
public static void WriteKnockoutDataBindComment(this IHtmlWriter writer, string name, DotvvmBindableObject control, DotvvmProperty property)
{
writer.WriteUnencodedText($"<!-- ko { name }: { control.GetValueBinding(property).GetKnockoutBindingExpression(control) } -->");
}
public static void WriteKnockoutDataBindComment(this IHtmlWriter writer, string name, DotvvmBindableObject control, DotvvmProperty property)
{
writer.WriteKnockoutDataBindComment(name, control.GetValueBinding(property).GetKnockoutBindingExpression(control));
}