/// <inheritdoc />
public virtual void Read(string parameterName, StringValues parameterValue)
{
try
{
PaginationQueryStringValueExpression constraint = GetPageConstraint(parameterValue);
if (constraint.Elements.Any(element => element.Scope == null))
{
AssertIsCollectionRequest();
}
if (parameterName == PageSizeParameterName)
{
ValidatePageSize(constraint);
_pageSizeConstraint = constraint;
}
else
{
ValidatePageNumber(constraint);
_pageNumberConstraint = constraint;
}
}
catch (QueryParseException exception)
{
throw new InvalidQueryStringParameterException(parameterName, "The specified paging is invalid.", exception.Message, exception);
}
}
protected virtual void ValidatePageNumber(PaginationQueryStringValueExpression constraint)
{
if (_options.MaximumPageNumber != null && constraint.Elements.Any(element => element.Value > _options.MaximumPageNumber.OneBasedValue))
{
throw new QueryParseException($"Page number cannot be higher than {_options.MaximumPageNumber}.");
}
if (constraint.Elements.Any(element => element.Value < 1))
{
throw new QueryParseException("Page number cannot be negative or zero.");
}
}
public PaginationQueryStringValueExpression Parse(string source, ResourceContext resourceContextInScope)
{
ArgumentGuard.NotNull(resourceContextInScope, nameof(resourceContextInScope));
_resourceContextInScope = resourceContextInScope;
Tokenize(source);
PaginationQueryStringValueExpression expression = ParsePagination();
AssertTokenStackIsEmpty();
return(expression);
}
private IList <PaginationElementQueryStringValueExpression> ParsePageSizeExpression(string pageSizeParameterValue)
{
if (pageSizeParameterValue == null)
{
return(new List <PaginationElementQueryStringValueExpression>());
}
ResourceContext requestResource = _request.SecondaryResource ?? _request.PrimaryResource;
var parser = new PaginationParser(_provider);
PaginationQueryStringValueExpression paginationExpression = parser.Parse(pageSizeParameterValue, requestResource);
return(paginationExpression.Elements.ToList());
}
protected virtual void ValidatePageSize(PaginationQueryStringValueExpression constraint)
{
if (_options.MaximumPageSize != null)
{
if (constraint.Elements.Any(element => element.Value > _options.MaximumPageSize.Value))
{
throw new QueryParseException($"Page size cannot be higher than {_options.MaximumPageSize}.");
}
if (constraint.Elements.Any(element => element.Value == 0))
{
throw new QueryParseException("Page size cannot be unconstrained.");
}
}
if (constraint.Elements.Any(element => element.Value < 0))
{
throw new QueryParseException("Page size cannot be negative.");
}
}