How do you call the default model binder within Web API in a custom IModelBinder? I know MVC has a default binder, but I can't use it with Web API. I just want to use the default Web API binder, and then run some custom logic after that (to avoid re-inventing the wheel).
public class CustomBinder : IModelBinder
{
public bool BindModel(HttpActionContext actionContext, ModelBindingContext bindingContext)
{
// Get default binding (can't mix Web API and MVC)
var defaultMvcBinder = System.Web.ModelBinding.ModelBinders.Binders.DefaultBinder;
var result = defaultMvcBinder.BindModel(actionContext, bindingContext); // Won't work
if (result == false) return false;
// ... set additional model properties
return true;
}
}
In case others stumble on this question, I had to implement the custom model binder with activation context since there is nothing to re-use from Web API. Here is the solution I am using for my limited scenarios that needed to be supported.
Usage
The implementation below allows me to let any model optionally use JsonProperty for model binding, but if not provided, will default to just the property name. It supports mappings from standard .NET types (string, int, double, etc). Not quite production ready, but it meets my use cases so far.
[ModelBinder(typeof(AttributeModelBinder))]
public class PersonModel
{
[JsonProperty("pid")]
public int PersonId { get; set; }
public string Name { get; set; }
}
This allows the following query string to be mapped in a request:
/api/endpoint?pid=1&name=test
Implementation
First, the solution defines a mapped property to track the source property of the model and the target name to use when setting the value from the value provider.
public class MappedProperty
{
public MappedProperty(PropertyInfo source)
{
this.Info = source;
this.Source = source.Name;
this.Target = source.GetCustomAttribute<JsonPropertyAttribute>()?.PropertyName ?? source.Name;
}
public PropertyInfo Info { get; }
public string Source { get; }
public string Target { get; }
}
Then, a custom model binder is defined to handle the mapping. It caches the reflected model properties to avoid repeating the reflection on subsequent calls. It may not be quite production ready, but initial testing has been promising.
public class AttributeModelBinder : IModelBinder
{
public static object _lock = new object();
private static Dictionary<Type, IEnumerable<MappedProperty>> _mappings = new Dictionary<Type, IEnumerable<MappedProperty>>();
public IEnumerable<MappedProperty> GetMapping(Type type)
{
if (_mappings.TryGetValue(type, out var result)) return result; // Found
lock (_lock)
{
if (_mappings.TryGetValue(type, out result)) return result; // Check again after lock
return (_mappings[type] = type.GetProperties().Select(p => new MappedProperty(p)));
}
}
public object Convert(Type target, string value)
{
try
{
var converter = TypeDescriptor.GetConverter(target);
if (converter != null)
return converter.ConvertFromString(value);
else
return target.IsValueType ? Activator.CreateInstance(target) : null;
}
catch (NotSupportedException)
{
return target.IsValueType ? Activator.CreateInstance(target) : null;
}
}
public void SetValue(object model, MappedProperty p, IValueProvider valueProvider)
{
var value = valueProvider.GetValue(p.Target)?.AttemptedValue;
if (value == null) return;
p.Info.SetValue(model, this.Convert(p.Info.PropertyType, value));
}
public bool BindModel(HttpActionContext actionContext, ModelBindingContext bindingContext)
{
try
{
var model = Activator.CreateInstance(bindingContext.ModelType);
var mappings = this.GetMapping(bindingContext.ModelType);
foreach (var p in mappings)
this.SetValue(model, p, bindingContext.ValueProvider);
bindingContext.Model = model;
return true;
}
catch (Exception ex)
{
return false;
}
}
}
Superfluous comment: I cannot believe I couldn't find a clear answer for this anywhere yet!
Using ASP.NET MVC model binding requires use of dot notation (variableName.propertyName) when using a query string. However, jQuery will use bracket notation when using a GET request, such as variableName[propertyName]=value&. ASP.NET MVC cannot understand this notation.
If I issued a POST request ASP.NET is able to properly bind the model because it uses dot notation in the posted body.
Is there any way to force ASP.NET to bind to a model that is a complex object when bracketed notation is used within a query string?
I'm not sure if this is the ideal solution, but I solved this using some reflection magic by implementing a generic implementation of IModelBinder. The stipulations on this implementation is that it assumes the elements from JavaScript in the query string are in camelCase and the class in C# is in PascalCase per standard styles. Additionally, it only functions on public [set-able] properties. Here's my implementation below:
public class BracketedQueryStringModelBinder<T> : IModelBinder
{
public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
var properties = typeof(T).GetProperties(BindingFlags.Instance | BindingFlags.Public).Where(p => p.CanWrite);
Dictionary<string, object> values = new Dictionary<string, object>();
foreach (var p in properties)
{
if (!IsNullable(p.PropertyType))
{
object val = TryGetValueType(p.PropertyType, bindingContext, p.Name);
if (val != null)
{
values.Add(p.Name, val);
}
}
else
{
object val = GetRefernceType(p.PropertyType, bindingContext, p.Name);
values.Add(p.Name, val);
}
}
if (values.Any())
{
object boundModel = Activator.CreateInstance<T>();
foreach (var p in properties.Where(i => values.ContainsKey(i.Name)))
{
p.SetValue(boundModel, values[p.Name]);
}
return boundModel;
}
return null;
}
private static bool IsNullable(Type t)
{
if (t == null)
throw new ArgumentNullException("t");
if (!t.IsValueType)
return true;
return Nullable.GetUnderlyingType(t) != null;
}
private static object TryGetValueType(Type type, ModelBindingContext ctx, string key)
{
if (string.IsNullOrEmpty(key))
throw new ArgumentNullException("key");
key = ConvertToPascalCase(key);
ValueProviderResult result = ctx.ValueProvider.GetValue(string.Concat(ctx.ModelName, "[", key, "]"));
if (result == null && ctx.FallbackToEmptyPrefix)
result = ctx.ValueProvider.GetValue(key);
if (result == null)
return null;
try
{
object returnVal = result.ConvertTo(type);
ctx.ModelState.SetModelValue(key, result);
return returnVal;
}
catch (Exception ex)
{
ctx.ModelState.AddModelError(ctx.ModelName, ex);
return null;
}
}
private static object GetRefernceType(Type type, ModelBindingContext ctx, string key)
{
if (string.IsNullOrEmpty(key))
throw new ArgumentNullException("key");
key = ConvertToPascalCase(key);
ValueProviderResult result = ctx.ValueProvider.GetValue(string.Concat(ctx.ModelName, "[", key, "]"));
if (result == null && ctx.FallbackToEmptyPrefix)
result = ctx.ValueProvider.GetValue(key);
if (result == null)
return null;
try
{
object returnVal = result.ConvertTo(type);
ctx.ModelState.SetModelValue(key, result);
return returnVal;
}
catch (Exception ex)
{
ctx.ModelState.AddModelError(ctx.ModelName, ex);
return null;
}
}
private static string ConvertToPascalCase(string str)
{
char firstChar = str[0];
if (char.IsUpper(firstChar))
return char.ToLower(firstChar) + str.Substring(1);
return str;
}
}
Then in your controller you can use it like this:
[HttpGet]
public ActionResult myAction([ModelBinder(typeof(BracketedQueryStringModelBinder<MyClass>))] MyClass mc = null)
{
...
}
The main downfall to this method is that if you do get a query string in dot notation this binding will fail since it doesn't revert back to the standard model binder.
I am try to implement ASP.NET MVC 5 WebAPI Patch. But there is a problem with int values and enums. JSON deserialize "think" that is better convert int to long, so is because that in my int propertie i recive allways 0...
So i found "Microsoft.AspNet.JsonPatch.JsonPatchDocument" (there has many others out ther)
Then problem is, i recive allways null in my model
public async Task<IHttpActionResult> Patch( int id, [FromBody] Microsoft.AspNet.JsonPatch.JsonPatchDocument<Customer> model)
{
//model is allways == null
}
I am using POSTMAN to send the patch as json in Body>Raw. Header is application/json.
I don´t understand why model is null... i need to do anything on WebApiConfig?
Still I tried to implements a custom JsonConverter, but the problem is i have a lots of Enum types, i need to create one for each enum? I try sothing like this:
public class Int32EnumConverter<T> : JsonConverter
but the problem is in WebApiConfig.cs you need to implement this:
config.Formatters.JsonFormatter.SerializerSettings.Converters.Add(new Int32EnumConverter<[I NEED HEAR Dynamic Enum Types>>);
There as any one to help me? Thanks!
Found! I did my on Delta Patch
public class JSONPatch<T>
{
private Dictionary<string, object> propsJson = new Dictionary<string, object>();
public JSONPatch()
{
Stream req = HttpContext.Current.Request.InputStream;
req.Seek(0, System.IO.SeekOrigin.Begin);
string json = new StreamReader(req).ReadToEnd();
propsJson = JsonConvert.DeserializeObject<Dictionary<string, object>>(json);
}
public JSONPatch(object model)
{
propsJson = JsonConvert.DeserializeObject<Dictionary<string, object>>(model.ToString());
}
public void Patch(T model)
{
PropertyInfo[] properties = model.GetType().GetProperties();
foreach (PropertyInfo property in properties)
{
try
{
if (!propsJson.Any(x => x.Key.Equals(property.Name, StringComparison.InvariantCultureIgnoreCase)))
continue;
KeyValuePair<string, object> item = propsJson.First(x => x.Key.Equals(property.Name, StringComparison.InvariantCultureIgnoreCase));
Type targetProp = model.GetType().GetProperty(property.Name).PropertyType;
Type targetNotNuable = Nullable.GetUnderlyingType(targetProp);
if (targetNotNuable != null)
{
targetProp = targetNotNuable;
}
if (item.Value.GetType() != typeof(Int64))
{
object newA = Convert.ChangeType(item.Value, targetProp);
model.GetType().GetProperty(property.Name).SetValue(model, newA, null);
}
else
{
int value = Convert.ToInt32(item.Value);
if (targetProp.IsEnum)
{
object newA = Enum.Parse(targetProp, value.ToString());
model.GetType().GetProperty(property.Name).SetValue(model, newA, null);
}
else
{
object newA = Convert.ChangeType(value, targetProp);
model.GetType().GetProperty(property.Name).SetValue(model, newA, null);
}
}
}
catch
{
}
}
}
}
and now:
public async Task<IHttpActionResult> Patch( int id, [FromBody]JSONPatch<Customer> model)
{
....
Atention: not 100% tested! fail for null values.
I have an ASP.NET Web API (version 4) REST service where I need to pass an array of integers.
Here is my action method:
public IEnumerable<Category> GetCategories(int[] categoryIds){
// code to retrieve categories from database
}
And this is the URL that I have tried:
/Categories?categoryids=1,2,3,4
You just need to add [FromUri] before parameter, looks like:
GetCategories([FromUri] int[] categoryIds)
And send request:
/Categories?categoryids=1&categoryids=2&categoryids=3
As Filip W points out, you might have to resort to a custom model binder like this (modified to bind to actual type of param):
public IEnumerable<Category> GetCategories([ModelBinder(typeof(CommaDelimitedArrayModelBinder))]long[] categoryIds)
{
// do your thing
}
public class CommaDelimitedArrayModelBinder : IModelBinder
{
public bool BindModel(HttpActionContext actionContext, ModelBindingContext bindingContext)
{
var key = bindingContext.ModelName;
var val = bindingContext.ValueProvider.GetValue(key);
if (val != null)
{
var s = val.AttemptedValue;
if (s != null)
{
var elementType = bindingContext.ModelType.GetElementType();
var converter = TypeDescriptor.GetConverter(elementType);
var values = Array.ConvertAll(s.Split(new[] { ","},StringSplitOptions.RemoveEmptyEntries),
x => { return converter.ConvertFromString(x != null ? x.Trim() : x); });
var typedValues = Array.CreateInstance(elementType, values.Length);
values.CopyTo(typedValues, 0);
bindingContext.Model = typedValues;
}
else
{
// change this line to null if you prefer nulls to empty arrays
bindingContext.Model = Array.CreateInstance(bindingContext.ModelType.GetElementType(), 0);
}
return true;
}
return false;
}
}
And then you can say:
/Categories?categoryids=1,2,3,4 and ASP.NET Web API will correctly bind your categoryIds array.
I recently came across this requirement myself, and I decided to implement an ActionFilter to handle this.
public class ArrayInputAttribute : ActionFilterAttribute
{
private readonly string _parameterName;
public ArrayInputAttribute(string parameterName)
{
_parameterName = parameterName;
Separator = ',';
}
public override void OnActionExecuting(HttpActionContext actionContext)
{
if (actionContext.ActionArguments.ContainsKey(_parameterName))
{
string parameters = string.Empty;
if (actionContext.ControllerContext.RouteData.Values.ContainsKey(_parameterName))
parameters = (string) actionContext.ControllerContext.RouteData.Values[_parameterName];
else if (actionContext.ControllerContext.Request.RequestUri.ParseQueryString()[_parameterName] != null)
parameters = actionContext.ControllerContext.Request.RequestUri.ParseQueryString()[_parameterName];
actionContext.ActionArguments[_parameterName] = parameters.Split(Separator).Select(int.Parse).ToArray();
}
}
public char Separator { get; set; }
}
I am applying it like so (note that I used 'id', not 'ids', as that is how it is specified in my route):
[ArrayInput("id", Separator = ';')]
public IEnumerable<Measure> Get(int[] id)
{
return id.Select(i => GetData(i));
}
And the public url would be:
/api/Data/1;2;3;4
You may have to refactor this to meet your specific needs.
In case someone would need - to achieve same or similar thing(like delete) via POST instead of FromUri, use FromBody and on client side(JS/jQuery) format param as $.param({ '': categoryids }, true)
c#:
public IHttpActionResult Remove([FromBody] int[] categoryIds)
jQuery:
$.ajax({
type: 'POST',
data: $.param({ '': categoryids }, true),
url: url,
//...
});
The thing with $.param({ '': categoryids }, true) is that it .net will expect post body to contain urlencoded value like =1&=2&=3 without parameter name, and without brackets.
Easy way to send array params to web api
API
public IEnumerable<Category> GetCategories([FromUri]int[] categoryIds){
// code to retrieve categories from database
}
Jquery : send JSON object as request params
$.get('api/categories/GetCategories',{categoryIds:[1,2,3,4]}).done(function(response){
console.log(response);
//success response
});
It will generate your request URL like
../api/categories/GetCategories?categoryIds=1&categoryIds=2&categoryIds=3&categoryIds=4
You may try this code for you to take comma separated values / an array of values to get back a JSON from webAPI
public class CategoryController : ApiController
{
public List<Category> Get(String categoryIDs)
{
List<Category> categoryRepo = new List<Category>();
String[] idRepo = categoryIDs.Split(',');
foreach (var id in idRepo)
{
categoryRepo.Add(new Category()
{
CategoryID = id,
CategoryName = String.Format("Category_{0}", id)
});
}
return categoryRepo;
}
}
public class Category
{
public String CategoryID { get; set; }
public String CategoryName { get; set; }
}
Output :
[
{"CategoryID":"4","CategoryName":"Category_4"},
{"CategoryID":"5","CategoryName":"Category_5"},
{"CategoryID":"3","CategoryName":"Category_3"}
]
ASP.NET Core 2.0 Solution (Swagger Ready)
Input
DELETE /api/items/1,2
DELETE /api/items/1
Code
Write the provider (how MVC knows what binder to use)
public class CustomBinderProvider : IModelBinderProvider
{
public IModelBinder GetBinder(ModelBinderProviderContext context)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (context.Metadata.ModelType == typeof(int[]) || context.Metadata.ModelType == typeof(List<int>))
{
return new BinderTypeModelBinder(typeof(CommaDelimitedArrayParameterBinder));
}
return null;
}
}
Write the actual binder (access all sorts of info about the request, action, models, types, whatever)
public class CommaDelimitedArrayParameterBinder : IModelBinder
{
public Task BindModelAsync(ModelBindingContext bindingContext)
{
var value = bindingContext.ActionContext.RouteData.Values[bindingContext.FieldName] as string;
// Check if the argument value is null or empty
if (string.IsNullOrEmpty(value))
{
return Task.CompletedTask;
}
var ints = value?.Split(',').Select(int.Parse).ToArray();
bindingContext.Result = ModelBindingResult.Success(ints);
if(bindingContext.ModelType == typeof(List<int>))
{
bindingContext.Result = ModelBindingResult.Success(ints.ToList());
}
return Task.CompletedTask;
}
}
Register it with MVC
services.AddMvc(options =>
{
// add custom binder to beginning of collection
options.ModelBinderProviders.Insert(0, new CustomBinderProvider());
});
Sample usage with a well documented controller for Swagger
/// <summary>
/// Deletes a list of items.
/// </summary>
/// <param name="itemIds">The list of unique identifiers for the items.</param>
/// <returns>The deleted item.</returns>
/// <response code="201">The item was successfully deleted.</response>
/// <response code="400">The item is invalid.</response>
[HttpDelete("{itemIds}", Name = ItemControllerRoute.DeleteItems)]
[ProducesResponseType(typeof(void), StatusCodes.Status204NoContent)]
[ProducesResponseType(typeof(void), StatusCodes.Status404NotFound)]
public async Task Delete(List<int> itemIds)
=> await _itemAppService.RemoveRangeAsync(itemIds);
EDIT: Microsoft recommends using a TypeConverter for these kids of operations over this approach. So follow the below posters advice and document your custom type with a SchemaFilter.
Instead of using a custom ModelBinder, you can also use a custom type with a TypeConverter.
[TypeConverter(typeof(StrListConverter))]
public class StrList : List<string>
{
public StrList(IEnumerable<string> collection) : base(collection) {}
}
public class StrListConverter : TypeConverter
{
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
{
return sourceType == typeof(string) || base.CanConvertFrom(context, sourceType);
}
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
{
if (value == null)
return null;
if (value is string s)
{
if (string.IsNullOrEmpty(s))
return null;
return new StrList(s.Split(','));
}
return base.ConvertFrom(context, culture, value);
}
}
The advantage is that it makes the Web API method's parameters very simple. You dont't even need to specify [FromUri].
public IEnumerable<Category> GetCategories(StrList categoryIds) {
// code to retrieve categories from database
}
This example is for a List of strings, but you could do categoryIds.Select(int.Parse) or simply write an IntList instead.
I originally used the solution that #Mrchief for years (it works great). But when when I added Swagger to my project for API documentation my end point was NOT showing up.
It took me a while, but this is what I came up with. It works with Swagger, and your API method signatures look cleaner:
In the end you can do:
// GET: /api/values/1,2,3,4
[Route("api/values/{ids}")]
public IHttpActionResult GetIds(int[] ids)
{
return Ok(ids);
}
WebApiConfig.cs
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
// Allow WebApi to Use a Custom Parameter Binding
config.ParameterBindingRules.Add(descriptor => descriptor.ParameterType == typeof(int[]) && descriptor.ActionDescriptor.SupportedHttpMethods.Contains(HttpMethod.Get)
? new CommaDelimitedArrayParameterBinder(descriptor)
: null);
// Allow ApiExplorer to understand this type (Swagger uses ApiExplorer under the hood)
TypeDescriptor.AddAttributes(typeof(int[]), new TypeConverterAttribute(typeof(StringToIntArrayConverter)));
// Any existing Code ..
}
}
Create a new class: CommaDelimitedArrayParameterBinder.cs
public class CommaDelimitedArrayParameterBinder : HttpParameterBinding, IValueProviderParameterBinding
{
public CommaDelimitedArrayParameterBinder(HttpParameterDescriptor desc)
: base(desc)
{
}
/// <summary>
/// Handles Binding (Converts a comma delimited string into an array of integers)
/// </summary>
public override Task ExecuteBindingAsync(ModelMetadataProvider metadataProvider,
HttpActionContext actionContext,
CancellationToken cancellationToken)
{
var queryString = actionContext.ControllerContext.RouteData.Values[Descriptor.ParameterName] as string;
var ints = queryString?.Split(',').Select(int.Parse).ToArray();
SetValue(actionContext, ints);
return Task.CompletedTask;
}
public IEnumerable<ValueProviderFactory> ValueProviderFactories { get; } = new[] { new QueryStringValueProviderFactory() };
}
Create a new class: StringToIntArrayConverter.cs
public class StringToIntArrayConverter : TypeConverter
{
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
{
return sourceType == typeof(string) || base.CanConvertFrom(context, sourceType);
}
}
Notes:
https://stackoverflow.com/a/47123965/862011 pointed me in the right direction
Swagger was only failing to pick my comma delimited end points when using the [Route] attribute
public class ArrayInputAttribute : ActionFilterAttribute
{
private readonly string[] _ParameterNames;
/// <summary>
///
/// </summary>
public string Separator { get; set; }
/// <summary>
/// cons
/// </summary>
/// <param name="parameterName"></param>
public ArrayInputAttribute(params string[] parameterName)
{
_ParameterNames = parameterName;
Separator = ",";
}
/// <summary>
///
/// </summary>
public void ProcessArrayInput(HttpActionContext actionContext, string parameterName)
{
if (actionContext.ActionArguments.ContainsKey(parameterName))
{
var parameterDescriptor = actionContext.ActionDescriptor.GetParameters().FirstOrDefault(p => p.ParameterName == parameterName);
if (parameterDescriptor != null && parameterDescriptor.ParameterType.IsArray)
{
var type = parameterDescriptor.ParameterType.GetElementType();
var parameters = String.Empty;
if (actionContext.ControllerContext.RouteData.Values.ContainsKey(parameterName))
{
parameters = (string)actionContext.ControllerContext.RouteData.Values[parameterName];
}
else
{
var queryString = actionContext.ControllerContext.Request.RequestUri.ParseQueryString();
if (queryString[parameterName] != null)
{
parameters = queryString[parameterName];
}
}
var values = parameters.Split(new[] { Separator }, StringSplitOptions.RemoveEmptyEntries)
.Select(TypeDescriptor.GetConverter(type).ConvertFromString).ToArray();
var typedValues = Array.CreateInstance(type, values.Length);
values.CopyTo(typedValues, 0);
actionContext.ActionArguments[parameterName] = typedValues;
}
}
}
public override void OnActionExecuting(HttpActionContext actionContext)
{
_ParameterNames.ForEach(parameterName => ProcessArrayInput(actionContext, parameterName));
}
}
Usage:
[HttpDelete]
[ArrayInput("tagIDs")]
[Route("api/v1/files/{fileID}/tags/{tagIDs}")]
public HttpResponseMessage RemoveFileTags(Guid fileID, Guid[] tagIDs)
{
_FileRepository.RemoveFileTags(fileID, tagIDs);
return Request.CreateResponse(HttpStatusCode.OK);
}
Request uri
http://localhost/api/v1/files/2a9937c7-8201-59b7-bc8d-11a9178895d0/tags/BBA5CD5D-F07D-47A9-8DEE-D19F5FA65F63,BBA5CD5D-F07D-47A9-8DEE-D19F5FA65F63
If you want to list/ array of integers easiest way to do this is accept the comma(,) separated list of string and convert it to list of integers.Do not forgot to mention [FromUri] attriubte.your url look like:
...?ID=71&accountID=1,2,3,289,56
public HttpResponseMessage test([FromUri]int ID, [FromUri]string accountID)
{
List<int> accountIdList = new List<int>();
string[] arrAccountId = accountId.Split(new char[] { ',' });
for (var i = 0; i < arrAccountId.Length; i++)
{
try
{
accountIdList.Add(Int32.Parse(arrAccountId[i]));
}
catch (Exception)
{
}
}
}
I have created a custom model binder which converts any comma separated values (only primitive, decimal, float, string) to their corresponding arrays.
public class CommaSeparatedToArrayBinder<T> : IModelBinder
{
public bool BindModel(HttpActionContext actionContext, ModelBindingContext bindingContext)
{
Type type = typeof(T);
if (type.IsPrimitive || type == typeof(Decimal) || type == typeof(String) || type == typeof(float))
{
ValueProviderResult val = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
if (val == null) return false;
string key = val.RawValue as string;
if (key == null) { bindingContext.ModelState.AddModelError(bindingContext.ModelName, "Wrong value type"); return false; }
string[] values = key.Split(',');
IEnumerable<T> result = this.ConvertToDesiredList(values).ToArray();
bindingContext.Model = result;
return true;
}
bindingContext.ModelState.AddModelError(bindingContext.ModelName, "Only primitive, decimal, string and float data types are allowed...");
return false;
}
private IEnumerable<T> ConvertToDesiredArray(string[] values)
{
foreach (string value in values)
{
var val = (T)Convert.ChangeType(value, typeof(T));
yield return val;
}
}
}
And how to use in Controller:
public IHttpActionResult Get([ModelBinder(BinderType = typeof(CommaSeparatedToArrayBinder<int>))] int[] ids)
{
return Ok(ids);
}
Make the method type [HttpPost], create a model that has one int[] parameter, and post with json:
/* Model */
public class CategoryRequestModel
{
public int[] Categories { get; set; }
}
/* WebApi */
[HttpPost]
public HttpResponseMessage GetCategories(CategoryRequestModel model)
{
HttpResponseMessage resp = null;
try
{
var categories = //your code to get categories
resp = Request.CreateResponse(HttpStatusCode.OK, categories);
}
catch(Exception ex)
{
resp = Request.CreateErrorResponse(HttpStatusCode.InternalServerError, ex);
}
return resp;
}
/* jQuery */
var ajaxSettings = {
type: 'POST',
url: '/Categories',
data: JSON.serialize({Categories: [1,2,3,4]}),
contentType: 'application/json',
success: function(data, textStatus, jqXHR)
{
//get categories from data
}
};
$.ajax(ajaxSettings);
Or you could just pass a string of delimited items and put it into an array or list on the receiving end.
I addressed this issue this way.
I used a post message to the api to send the list of integers as data.
Then I returned the data as an ienumerable.
The sending code is as follows:
public override IEnumerable<Contact> Fill(IEnumerable<int> ids)
{
IEnumerable<Contact> result = null;
if (ids!=null&&ids.Count()>0)
{
try
{
using (var client = new HttpClient())
{
client.BaseAddress = new Uri("http://localhost:49520/");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
String _endPoint = "api/" + typeof(Contact).Name + "/ListArray";
HttpResponseMessage response = client.PostAsJsonAsync<IEnumerable<int>>(_endPoint, ids).Result;
response.EnsureSuccessStatusCode();
if (response.IsSuccessStatusCode)
{
result = JsonConvert.DeserializeObject<IEnumerable<Contact>>(response.Content.ReadAsStringAsync().Result);
}
}
}
catch (Exception)
{
}
}
return result;
}
The receiving code is as follows:
// POST api/<controller>
[HttpPost]
[ActionName("ListArray")]
public IEnumerable<Contact> Post([FromBody]IEnumerable<int> ids)
{
IEnumerable<Contact> result = null;
if (ids != null && ids.Count() > 0)
{
return contactRepository.Fill(ids);
}
return result;
}
It works just fine for one record or many records. The fill is an overloaded method using DapperExtensions:
public override IEnumerable<Contact> Fill(IEnumerable<int> ids)
{
IEnumerable<Contact> result = null;
if (ids != null && ids.Count() > 0)
{
using (IDbConnection dbConnection = ConnectionProvider.OpenConnection())
{
dbConnection.Open();
var predicate = Predicates.Field<Contact>(f => f.id, Operator.Eq, ids);
result = dbConnection.GetList<Contact>(predicate);
dbConnection.Close();
}
}
return result;
}
This allows you to fetch data from a composite table (the id list), and then return the records you are really interested in from the target table.
You could do the same with a view, but this gives you a little more control and flexibility.
In addition, the details of what you are seeking from the database are not shown in the query string. You also do not have to convert from a csv file.
You have to keep in mind when using any tool like the web api 2.x interface is that the get, put, post, delete, head, etc., functions have a general use, but are not restricted to that use.
So, while post is generally used in a create context in the web api interface, it is not restricted to that use. It is a regular html call that can be used for any purpose permitted by html practice.
In addition, the details of what is going on are hidden from those "prying eyes" we hear so much about these days.
The flexibility in naming conventions in the web api 2.x interface and use of regular web calling means you send a call to the web api that misleads snoopers into thinking you are really doing something else. You can use "POST" to really retrieve data, for example.
My solution was to create an attribute to validate strings, it does a bunch of extra common features, including regex validation that you can use to check for numbers only and then later I convert to integers as needed...
This is how you use:
public class MustBeListAndContainAttribute : ValidationAttribute
{
private Regex regex = null;
public bool RemoveDuplicates { get; }
public string Separator { get; }
public int MinimumItems { get; }
public int MaximumItems { get; }
public MustBeListAndContainAttribute(string regexEachItem,
int minimumItems = 1,
int maximumItems = 0,
string separator = ",",
bool removeDuplicates = false) : base()
{
this.MinimumItems = minimumItems;
this.MaximumItems = maximumItems;
this.Separator = separator;
this.RemoveDuplicates = removeDuplicates;
if (!string.IsNullOrEmpty(regexEachItem))
regex = new Regex(regexEachItem, RegexOptions.Compiled | RegexOptions.Singleline | RegexOptions.IgnoreCase);
}
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
var listOfdValues = (value as List<string>)?[0];
if (string.IsNullOrWhiteSpace(listOfdValues))
{
if (MinimumItems > 0)
return new ValidationResult(this.ErrorMessage);
else
return null;
};
var list = new List<string>();
list.AddRange(listOfdValues.Split(new[] { Separator }, System.StringSplitOptions.RemoveEmptyEntries));
if (RemoveDuplicates) list = list.Distinct().ToList();
var prop = validationContext.ObjectType.GetProperty(validationContext.MemberName);
prop.SetValue(validationContext.ObjectInstance, list);
value = list;
if (regex != null)
if (list.Any(c => string.IsNullOrWhiteSpace(c) || !regex.IsMatch(c)))
return new ValidationResult(this.ErrorMessage);
return null;
}
}
I just added the Query key (Refit lib) in the property for the request.
[Query(CollectionFormat.Multi)]
public class ExampleRequest
{
[FromQuery(Name = "name")]
public string Name { get; set; }
[AliasAs("category")]
[Query(CollectionFormat.Multi)]
public List<string> Categories { get; set; }
}
All other solutions need too much work. I was trying to use IEnumerable<long> or long[] in a HttpGet method parameter, but I see no point of doing all the work just to make the signature of the handler method parameter long[]. I ended up just making it string, and then separated it within the handler. Took me one line.
public async Task<IActionResult> SomeHandler(string idsString)
{
var ids = idsString.Split(',').Select(x => long.Parse(x));
Now you can just pass the numbers like
.../SomeHandler?idsString=123,456,789,012