169 lines
8.2 KiB
C#
169 lines
8.2 KiB
C#
using System;
|
|
using System.Linq;
|
|
using System.Threading.Tasks;
|
|
using EmbedIO.Utilities;
|
|
using Swan;
|
|
|
|
namespace EmbedIO.WebApi
|
|
{
|
|
/// <summary>
|
|
/// <para>Specifies that a parameter of a controller method will receive the value of a field,
|
|
/// obtained by deserializing a request URL query.</para>
|
|
/// <para>The parameter carrying this attribute can be either a simple type or a one-dimension array.</para>
|
|
/// <para>If multiple values are present for the field, a non-array parameter will receive the last specified value,
|
|
/// while an array parameter will receive an array of field values converted to the element type of the
|
|
/// parameter.</para>
|
|
/// <para>If a single value is present for the field, a non-array parameter will receive the value converted
|
|
/// to the type of the parameter, while an array parameter will receive an array of length 1, containing
|
|
/// the value converted to the element type of the parameter</para>
|
|
/// <para>If no values are present for the field and the <see cref="BadRequestIfMissing"/> property is
|
|
/// <see langword="true" />, a <c>400 Bad Request</c> response will be sent to the client, with a message
|
|
/// specifying the name of the missing field.</para>
|
|
/// <para>If no values are present for the field and the <see cref="BadRequestIfMissing"/> property is
|
|
/// <see langword="false" />, a non-array parameter will receive the default value for its type, while
|
|
/// an array parameter will receive an array of length 0.</para>
|
|
/// <para>This class cannot be inherited.</para>
|
|
/// </summary>
|
|
/// <seealso cref="Attribute" />
|
|
/// <seealso cref="IRequestDataAttribute{TController,TData}" />
|
|
/// <seealso cref="IRequestDataAttribute{TController}" />
|
|
[AttributeUsage(AttributeTargets.Parameter)]
|
|
public sealed class QueryFieldAttribute :
|
|
Attribute,
|
|
IRequestDataAttribute<WebApiController, string>,
|
|
IRequestDataAttribute<WebApiController, string[]>,
|
|
IRequestDataAttribute<WebApiController>
|
|
{
|
|
/// <summary>
|
|
/// Initializes a new instance of the <see cref="QueryFieldAttribute"/> class.
|
|
/// The name of the query field to extract will be equal to the name of the parameter
|
|
/// carrying this attribute.
|
|
/// </summary>
|
|
public QueryFieldAttribute()
|
|
: this(false, null)
|
|
{
|
|
}
|
|
|
|
/// <summary>
|
|
/// Initializes a new instance of the <see cref="QueryFieldAttribute"/> class.
|
|
/// </summary>
|
|
/// <param name="fieldName">The name of the query field to extract.</param>
|
|
/// <exception cref="ArgumentNullException"><paramref name="fieldName"/> is <see langword="null"/>.</exception>
|
|
/// <exception cref="ArgumentException"><paramref name="fieldName"/> is the empty string (<c>""</c>).</exception>
|
|
public QueryFieldAttribute(string fieldName)
|
|
: this(false, Validate.NotNullOrEmpty(nameof(fieldName), fieldName))
|
|
{
|
|
}
|
|
|
|
/// <summary>
|
|
/// Initializes a new instance of the <see cref="QueryFieldAttribute" /> class.
|
|
/// The name of the query field to extract will be equal to the name of the parameter
|
|
/// carrying this attribute.
|
|
/// </summary>
|
|
/// <param name="badRequestIfMissing">If set to <see langword="true" />, a <c>400 Bad Request</c>
|
|
/// response will be sent to the client if no values are found for the field; if set to
|
|
/// <see langword="false" />, a default value will be assumed.</param>
|
|
public QueryFieldAttribute(bool badRequestIfMissing)
|
|
: this(badRequestIfMissing, null)
|
|
{
|
|
}
|
|
|
|
/// <summary>
|
|
/// Initializes a new instance of the <see cref="QueryFieldAttribute"/> class.
|
|
/// </summary>
|
|
/// <param name="fieldName">The name of the query field to extract.</param>
|
|
/// <exception cref="ArgumentNullException"><paramref name="fieldName"/> is <see langword="null"/>.</exception>
|
|
/// <exception cref="ArgumentException"><paramref name="fieldName"/> is the empty string (<c>""</c>).</exception>
|
|
/// <param name="badRequestIfMissing">If set to <see langword="true" />, a <c>400 Bad Request</c>
|
|
/// response will be sent to the client if no values are found for the field; if set to
|
|
/// <see langword="false" />, a default value will be assumed.</param>
|
|
public QueryFieldAttribute(string fieldName, bool badRequestIfMissing)
|
|
: this(badRequestIfMissing, Validate.NotNullOrEmpty(nameof(fieldName), fieldName))
|
|
{
|
|
}
|
|
|
|
private QueryFieldAttribute(bool badRequestIfMissing, string? fieldName)
|
|
{
|
|
BadRequestIfMissing = badRequestIfMissing;
|
|
FieldName = fieldName;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Gets the name of the query field that this attribute will extract,
|
|
/// or <see langword="null" /> if the name of the parameter carrying this
|
|
/// attribute is to be used as field name.
|
|
/// </summary>
|
|
public string? FieldName { get; }
|
|
|
|
/// <summary>
|
|
/// <para>Gets or sets a value indicating whether to send a <c>400 Bad Request</c> response
|
|
/// to the client if the URL query contains no values for the field.</para>
|
|
/// <para>If this property is <see langword="true"/> and the URL query
|
|
/// contains no values for the field, the <c>400 Bad Request</c> response sent
|
|
/// to the client will contain a reference to the missing field.</para>
|
|
/// <para>If this property is <see langword="false"/> and the URL query
|
|
/// contains no values for the field, the default value for the parameter
|
|
/// (or a zero-length array if the parameter is of an array type)
|
|
/// will be passed to the controller method.</para>
|
|
/// </summary>
|
|
public bool BadRequestIfMissing { get; }
|
|
|
|
Task<string?> IRequestDataAttribute<WebApiController, string>.GetRequestDataAsync(
|
|
WebApiController controller,
|
|
string parameterName)
|
|
{
|
|
var data = controller.HttpContext.GetRequestQueryData();
|
|
|
|
var fieldName = FieldName ?? parameterName;
|
|
if (!data.ContainsKey(fieldName) && BadRequestIfMissing)
|
|
throw HttpException.BadRequest($"Missing query field {fieldName}.");
|
|
|
|
return Task.FromResult(data.GetValues(fieldName)?.LastOrDefault());
|
|
}
|
|
|
|
Task<string[]> IRequestDataAttribute<WebApiController, string[]>.GetRequestDataAsync(
|
|
WebApiController controller,
|
|
string parameterName)
|
|
{
|
|
var data = controller.HttpContext.GetRequestQueryData();
|
|
|
|
var fieldName = FieldName ?? parameterName;
|
|
if (!data.ContainsKey(fieldName) && BadRequestIfMissing)
|
|
throw HttpException.BadRequest($"Missing query field {fieldName}.");
|
|
|
|
return Task.FromResult(data.GetValues(fieldName) ?? Array.Empty<string>());
|
|
}
|
|
|
|
Task<object?> IRequestDataAttribute<WebApiController>.GetRequestDataAsync(
|
|
WebApiController controller,
|
|
Type type,
|
|
string parameterName)
|
|
{
|
|
var data = controller.HttpContext.GetRequestQueryData();
|
|
|
|
var fieldName = FieldName ?? parameterName;
|
|
if (!data.ContainsKey(fieldName) && BadRequestIfMissing)
|
|
throw HttpException.BadRequest($"Missing query field {fieldName}.");
|
|
|
|
if (type.IsArray)
|
|
{
|
|
var fieldValues = data.GetValues(fieldName) ?? Array.Empty<string>();
|
|
if (!FromString.TryConvertTo(type, fieldValues, out var result))
|
|
throw HttpException.BadRequest($"Cannot convert field {fieldName} to an array of {type.GetElementType().Name}.");
|
|
|
|
return Task.FromResult(result);
|
|
}
|
|
else
|
|
{
|
|
var fieldValue = data.GetValues(fieldName)?.LastOrDefault();
|
|
if (fieldValue == null)
|
|
return Task.FromResult(type.IsValueType ? Activator.CreateInstance(type) : null);
|
|
|
|
if (!FromString.TryConvertTo(type, fieldValue, out var result))
|
|
throw HttpException.BadRequest($"Cannot convert field {fieldName} to {type.Name}.");
|
|
|
|
return Task.FromResult(result);
|
|
}
|
|
}
|
|
}
|
|
} |