private ILinkViewModel GetPreviousLink(int total, int skip, int take)
{
if (skip == 0)
{
return(null);
}
if (skip > total)
{
return(GetLastLink(total, take));
}
var previousPage = Math.Max(skip - take, 0);
if (previousPage <= 0)
{
return(GetFirstLink(take));
}
var newLink = new PlaceholderLinkViewModel(_meta);
SafeSetValue(newLink.Values, nameof(take), take);
SafeSetValue(newLink.Values, nameof(skip), previousPage);
newLink.Href = GetNewHrefByValues(newLink.Values);
return(newLink);
}
private ILinkViewModel GetFirstLink(int take)
{
var newLink = new PlaceholderLinkViewModel(_meta);
SafeSetValue(newLink.Values, nameof(take), take);
SafeSetValue(newLink.Values, "skip", 0);
newLink.Href = GetNewHrefByValues(newLink.Values);
return(newLink);
}
public FormViewModel(string path, string method, string relation, IEnumerable <FormFieldViewModel> fields)
{
Meta = new PlaceholderLinkViewModel
{
Href = path,
Method = method,
Relations = new[] { relation }
};
Items = fields.ToArray();
}
private ILinkViewModel GetNextLink(int total, int skip, int take)
{
var nextPage = skip + take;
if (nextPage >= total)
{
return(null);
}
var newLink = new PlaceholderLinkViewModel(_meta);
SafeSetValue(newLink.Values, nameof(take), take);
SafeSetValue(newLink.Values, nameof(skip), nextPage);
newLink.Href = GetNewHrefByValues(newLink.Values);
return(newLink);
}
private ILinkViewModel GetLastLink(int total, int take)
{
if (total <= take)
{
return(null);
}
var skip = Math.Ceiling((total - (double)take) / take) * take;
var newLink = new PlaceholderLinkViewModel(_meta);
SafeSetValue(newLink.Values, nameof(take), take);
SafeSetValue(newLink.Values, nameof(skip), skip);
newLink.Href = GetNewHrefByValues(newLink.Values);
return(newLink);
}
public static PlaceholderLinkViewModel ToCollection(string hrefPattern, string method = "GET",
object values = null)
{
var placeholderLinkViewModel = new PlaceholderLinkViewModel
{
Method = method,
Relations = new[] { "collection" },
Values = new RouteValueDictionary(values)
};
placeholderLinkViewModel.Href = hrefPattern;
foreach (var newLinkValue in placeholderLinkViewModel.Values)
{
var hrefKey = "{" + newLinkValue.Key + "}";
placeholderLinkViewModel.Href =
placeholderLinkViewModel.Href.Replace(hrefKey, newLinkValue.Value.ToString());
}
return(placeholderLinkViewModel);
}
