private static IEnumerable <Link> GeneratePageLinks <TPage>(TPage page, Func <TemplateParameter <int?>, TemplateParameter <int?>, Maybe <Link> > linkFactory)
where TPage : ICollectionPage
{
var perPageParameter = page.pageSize == PaginationConstants.DEFAULT_PAGE_SIZE
? TemplateParameter.Force <int?>(null)
: TemplateParameter.Force <int?>(page.pageSize);
var currentPageParameter = page.currentPage == PaginationConstants.FIRST_PAGE
? TemplateParameter.Force <int?>(null)
: TemplateParameter.Force <int?>(page.currentPage);
var previousPage = page.currentPage - 1;
var nextPage = page.currentPage + 1;
var selfLink = linkFactory(currentPageParameter, perPageParameter);
var firstLink =
PaginationConstants.FIRST_PAGE == page.currentPage ? selfLink
: linkFactory(TemplateParameter.Force <int?>(null), perPageParameter);
var lastLink =
page.lastPage == page.currentPage ? selfLink
: page.lastPage == PaginationConstants.FIRST_PAGE ? firstLink
: linkFactory(TemplateParameter.Force <int?>(page.lastPage), perPageParameter);
var nextLink =
nextPage > page.lastPage ? Maybe.None <Link>()
: nextPage == page.lastPage ? lastLink
: linkFactory(TemplateParameter.Force <int?>(nextPage), perPageParameter);
var previousLink =
previousPage <PaginationConstants.FIRST_PAGE?Maybe.None <Link>()
: previousPage == PaginationConstants.FIRST_PAGE?firstLink
: previousPage> page.lastPage ? null
: previousPage == page.lastPage ? lastLink
: linkFactory(TemplateParameter.Force <int?>(previousPage), perPageParameter);
var specificLink =
PaginationConstants.FIRST_PAGE == page.lastPage ? null
: linkFactory(TemplateParameter.Create <int?>(), perPageParameter).SetDescription("Specific page");
selfLink.SetSelf();
firstLink.AddRel <FirstRelation>();
lastLink.AddRel <LastRelation>();
nextLink.AddRel <NextRelation>();
previousLink.AddRel <PreviousRelation>();
return(new[] { specificLink, selfLink, firstLink, lastLink, nextLink, previousLink }
.Where(x => x.HasValue)
.Select(x => x.Value)
.Distinct()
.Select(x => SetDescription(x, page.currentPage, page.lastPage)));
}
public Maybe <Link> ToAction(MethodInfo method, ReadOnlyCollection <Expression> arguments)
{
var parameters = method.GetParameters();
var isTemplate = false;
var wrappedValues = Enumerable.Range(0, arguments.Count).Select(x =>
{
var argument = arguments[x];
var unaryExpression = argument as UnaryExpression;
TemplateParameter value;
if (unaryExpression != null && unaryExpression.Operand.Type.GetTypeInfo().IsSubclassOf(typeof(TemplateParameter)))
{
value = Expression.Lambda(unaryExpression.Operand).Compile().DynamicInvoke() as TemplateParameter;
}
else
{
value = TemplateParameter.Force(Expression.Lambda(argument).Compile().DynamicInvoke());
}
return(new
{
Name = parameters[x].Name,
Value = value
});
})
.ToDictionary(x => x.Name, x => x.Value);
var actionAttribute = ExtractActionAttribute(method);
if (actionAttribute != null && HttpContext != null && HttpContext.RequestServices != null)
{
var task = actionAttribute.ExecuteSuitableValidationsAsync(HttpContext.RequestServices, wrappedValues);
var problem = task.WaitAndGetValue();
if (problem.HasValue)
{
return(Maybe.None <Link>());
}
}
var values = wrappedValues.ToDictionary(
x => x.Key,
x =>
{
if (x.Value.ForceValue)
{
return(x.Value.ForcedValue);
}
else
{
isTemplate = true;
return(string.Format("{{{0}}}", x.Value.CustomText ?? x.Key));
}
});
var link = new Link()
{
Href = ExtractUrl(method, values)
};
if (isTemplate)
{
link.Href = link.Href?.Replace("%7B", "{").Replace("%7D", "}");
link.Relation.Add <TemplateRelation>();
}
if (actionAttribute != null)
{
actionAttribute.UpdateLinkMethodInfo(link);
}
return(Maybe.From(link));
}