Usually CollectionModel will return an _embedded array, but in this example:
#GetMapping("/{id}/productMaterials")
public ResponseEntity<?> getProductMaterials(#PathVariable Integer id) {
Optional<Material> optionalMaterial = materialRepository.findById(id);
if (optionalMaterial.isPresent()) {
List<ProductMaterial> productMaterials = optionalMaterial.get().getProductMaterials();
CollectionModel<ProductMaterialModel> productMaterialModels =
new ProductMaterialModelAssembler(ProductMaterialController.class, ProductMaterialModel.class).
toCollectionModel(productMaterials);
return ResponseEntity.ok().body(productMaterialModels);
}
return ResponseEntity.badRequest().body("no such material");
}
if the productMaterials is empty CollectionModel will not render the _embedded array which will break the client. Is there any ways to fix this?
if (optionalMaterial.isPresent()) {
List<ProductMaterial> productMaterials = optionalMaterial.get().getProductMaterials();
CollectionModel<ProductMaterialModel> productMaterialModels =
new ProductMaterialModelAssembler(ProductMaterialController.class, ProductMaterialModel.class).
toCollectionModel(productMaterials);
if(productMaterialModels.isEmpty()) {
EmbeddedWrappers wrappers = new EmbeddedWrappers(false);
EmbeddedWrapper wrapper = wrappers.emptyCollectionOf(ProductMaterialModel.class);
Resources<Object> resources = new Resources<>(Arrays.asList(wrapper));
return ResponseEntity.ok(new Resources<>(resources));
} else {
return ResponseEntity.ok().body(productMaterialModels);
}
}
Related
I have the following Spring #RestController method:
public MappingJacksonValue getUserView(User viewer, Long vieweeid) {
User viewee = getUser(vieweeid);
if(viewee == null) throw new ResponseStatusException(
HttpStatus.NOT_FOUND, "entity not found"
);
final MappingJacksonValue result = new MappingJacksonValue(viewee);
Class view = Views.Minimal.class;
if(viewer.getId().equals(viewee.getId())) {
view = Views.Full.class;
}
...some lines omitted...
result.setSerializationView(view);
return result;
}
Although this is working fine, I am not happy with throwing an exception to return a 404 if the entity requested is not found.
What is the best practice to handle this?
If you like, you can make your method return ResponseEntity<MappingJacksonValue> and then return ResponseEntity.notFound().build():
public ResponseEntity<MappingJacksonValue> getUserView(User viewer, Long vieweeid) {
User viewee = getUser(vieweeid);
if(viewee == null) return ResponseEntity.notFound().build();
final MappingJacksonValue result = new MappingJacksonValue(viewee);
Class view = Views.Minimal.class;
if(viewer.getId().equals(viewee.getId())) {
view = Views.Full.class;
}
...some lines omitted...
result.setSerializationView(view);
return ResponseEntity.ok(result);
}
When i am trying to clear my observable collection it is crashing.Is there any
other way to clear it??
ObservableCollection<Group> _groupList = new ObservableCollection<Group>();
public ObservableCollection<Group> GroupList
{
get
{
return _groupList;
}
set
{
_groupList = value;
RaisePropertyChanged("GroupList");
}
}
You can simple make a new collection:
GroupList = new ObservableCollection<Group>();
There's a clear function
GroupList.Clear();
or
GroupList = new ObservableCollection<Group>();
Also try declare you list this way :
ObservableCollection<Group> _groupList;
public ObservableCollection<Group> GroupList
{
get { return _groupList; }
set { SetValue(ref _groupList, value); }
}
I am new to Web API and REST services and looking to build a simple REST server which accepts file uploads. I found out grapevine which is simple and easy to understand. I couldn't find any file upload example?
This is an example using System.Web.Http
var streamProvider = new MultipartFormDataStreamProvider(ServerUploadFolder);
await Request.Content.ReadAsMultipartAsync(streamProvider);
but the grapevine Request property does not have any method to do that. Can someone point me to an example?
If you are trying to upload a file as a binary payload, see this question/answer on GitHub.
If you are trying to upload a file from a form submission, that will be a little bit trickier, as the multi-part payload parsers haven't been added yet, but it is still possible.
The following code sample is complete untested, and I just wrote this off the top of my head, so it might not be the best solution, but it's a starting point:
public static class RequestExtensions
{
public static IDictionary<string, string> ParseFormUrlEncoded(this IHttpRequest request)
{
var data = new Dictionary<string, string>();
foreach (var tuple in request.Payload.Split('='))
{
var parts = tuple.Split('&');
var key = Uri.UnescapeDataString(parts[0]);
var val = Uri.UnescapeDataString(parts[1]);
if (!data.ContainsKey(key)) data.Add(key, val);
}
return data;
}
public static IDictionary<string, FormElement> ParseFormData(this IHttpRequest request)
{
var data = new Dictionary<string, FormElement>();
var boundary = GetBoundary(request.Headers.Get("Content-Type"));
if (boundary == null) return data;
foreach (var part in request.Payload.Split(new[] { boundary }, StringSplitOptions.RemoveEmptyEntries))
{
var element = new FormElement(part);
if (!data.ContainsKey(element.Name)) data.Add(element.Name, element);
}
return data;
}
private static string GetBoundary(string contenttype)
{
if (string.IsNullOrWhiteSpace(contenttype)) return null;
return (from part in contenttype.Split(';', ',')
select part.TrimStart().TrimEnd().Split('=')
into parts
where parts[0].Equals("boundary", StringComparison.CurrentCultureIgnoreCase)
select parts[1]).FirstOrDefault();
}
}
public class FormElement
{
public string Name => _dispositionParams["name"];
public string FileName => _dispositionParams["filename"];
public Dictionary<string, string> Headers { get; private set; }
public string Value { get; }
private Dictionary<string, string> _dispositionParams;
public FormElement(string data)
{
var parts = data.Split(new [] { "\r\n\r\n", "\n\n" }, StringSplitOptions.None);
Value = parts[1];
ParseHeaders(parts[0]);
ParseParams(Headers["Content-Disposition"]);
}
private void ParseHeaders(string data)
{
Headers = data.TrimStart().TrimEnd().Split(new[] {"\r\n", "\n"}, StringSplitOptions.RemoveEmptyEntries).Select(header => header.Split(new[] {':'})).ToDictionary(parts => parts[0].TrimStart().TrimEnd(), parts => parts[1].TrimStart().TrimEnd());
}
private void ParseParams(string data)
{
_dispositionParams = new Dictionary<string, string>();
foreach (var part in data.Split(new[] {';'}))
{
if (part.IndexOf("=") == -1) continue;
var parts = part.Split(new[] {'='});
_dispositionParams.Add(parts[0].TrimStart(' '), parts[1].TrimEnd('"').TrimStart('"'));
}
}
}
If you are looking for something async to use immediately, you can try to implement the answer to this stackoverflow question, which has not been tested by me.
It's the first time that I use EmitMapper.
I have a list of object ex: Customer and I would like to map this list in a ienumerable of CustomerDTO how can I do that?
Tnx
It's straightforward if you have a list and want to convert it to list of DTOs:
var mapper = ObjectMapperManager.DefaultInstance.GetMapper<Customer, CustomerDTO>();
IEnumerable<CustomerDTO> dtos = listOfCustomer.Select(mapper.map);
The preblem is when the list is in another object, for example User and UserDTO:
class User {
public List<Customer> Customers { get; set; }
}
class UserDTO {
public IEnumerable<CustomerDTO> Customers { get; set; }
}
It seems that EmitMapper does not support conversion from List to Enumerable. A way to support it would be:
var customerMapper = ObjectMapperManager
.DefaultInstance.GetMapper<Customer, CustomerDTO>();
var mapper = ObjectMapperManager.DefaultInstance
.GetMapper<User, UserDTO>(
new DefaultMapConfig()
.ConvertUsing<List<Customer>, IEnumerable<CustomerDTO>>(
a => a.Select(customerMapper.Map))
);
This can be done creating a custom class, implementing the interface "ICustomConverterProvider" and adding a ConvertGeneric to the "DefaultMapConfig".
Looking on the source code of EmitMapper, i found a class named "ArraysConverterProvider", which is the default generic converter from ICollections to Arrays.
Adapting the code from this class to work with IEnumerable collections:
class GenericIEnumerableConverterProvider : ICustomConverterProvider
{
public CustomConverterDescriptor GetCustomConverterDescr(
Type from,
Type to,
MapConfigBaseImpl mappingConfig)
{
var tFromTypeArgs = DefaultCustomConverterProvider.GetGenericArguments(from);
var tToTypeArgs = DefaultCustomConverterProvider.GetGenericArguments(to);
if (tFromTypeArgs == null || tToTypeArgs == null || tFromTypeArgs.Length != 1 || tToTypeArgs.Length != 1)
{
return null;
}
var tFrom = tFromTypeArgs[0];
var tTo = tToTypeArgs[0];
if (tFrom == tTo && (tFrom.IsValueType || mappingConfig.GetRootMappingOperation(tFrom, tTo).ShallowCopy))
{
return new CustomConverterDescriptor
{
ConversionMethodName = "Convert",
ConverterImplementation = typeof(GenericIEnumerableConverter_OneTypes<>),
ConverterClassTypeArguments = new[] { tFrom }
};
}
return new CustomConverterDescriptor
{
ConversionMethodName = "Convert",
ConverterImplementation = typeof(GenericIEnumerableConverter_DifferentTypes<,>),
ConverterClassTypeArguments = new[] { tFrom, tTo }
};
}
}
class GenericIEnumerableConverter_DifferentTypes<TFrom, TTo> : ICustomConverter
{
private Func<TFrom, TTo> _converter;
public IEnumerable<TTo> Convert(IEnumerable<TFrom> from, object state)
{
if (from == null)
{
return null;
}
TTo[] result = new TTo[from.Count()];
int idx = 0;
foreach (var f in from)
{
result[idx++] = _converter(f);
}
return result;
}
public void Initialize(Type from, Type to, MapConfigBaseImpl mappingConfig)
{
var staticConverters = mappingConfig.GetStaticConvertersManager() ?? StaticConvertersManager.DefaultInstance;
var staticConverterMethod = staticConverters.GetStaticConverter(typeof(TFrom), typeof(TTo));
if (staticConverterMethod != null)
{
_converter = (Func<TFrom, TTo>)Delegate.CreateDelegate(
typeof(Func<TFrom, TTo>),
null,
staticConverterMethod
);
}
else
{
_subMapper = ObjectMapperManager.DefaultInstance.GetMapperImpl(typeof(TFrom), typeof(TTo), mappingConfig);
_converter = ConverterBySubmapper;
}
}
ObjectsMapperBaseImpl _subMapper;
private TTo ConverterBySubmapper(TFrom from)
{
return (TTo)_subMapper.Map(from);
}
}
class GenericIEnumerableConverter_OneTypes<T>
{
public IEnumerable<T> Convert(IEnumerable<T> from, object state)
{
if (from == null)
{
return null;
}
return from;
}
}
This code is just a copy with a minimum of adaptation as possible and can be applyed to objects with many levels of hierarchy.
You can use the above code with the following command:
new DefaultMapConfig().ConvertGeneric(
typeof(IEnumerable<>),
typeof(IEnumerable<>),
new GenericIEnumerableConverterProvider());
This saved my day and I hope to save yours too! hehehe
I will call AnalyseLinqUpdate()
I think code itself clear..
I have to find behavior for each dictionary value and replace the value with the behavior I get from the method 'GiveBehavior'
void AnalyseLinqUpdate()
{
Dictionary<string, string> rawCollection = new Dictionary<string, string>();
rawCollection.Add("PT-1", "PTC-1");
rawCollection.Add("PT-2", "PTC-1");
rawCollection.Add("PT-3", "PTC-2");
rawCollection.Add("PT-4", "PTC-2");
rawCollection.Add("PT-5", "PTC-3");
rawCollection.Add("PT-6", "PTC-3");
//update here
// call GiveBehavior("PTC-1");
//returns a string that needs to be updated in place of "PTC-1"
}
string GiveBehavior(string ptc)
{
StringComparison ignoreCase = StringComparison.OrdinalIgnoreCase;
ptc = ptc.Trim();
if (ptc.Equals("PTC-1", ignoreCase))
{
return "PTB-1";
}
else if (ptc.Equals("PTC-1", ignoreCase))
{
return "PTB-2";
}
else
{
return "PTB-3";
}
}
Currently I have done like:
List<string> keys = rawCollection.Keys.ToList();
foreach (string key in keys)
{
string behavior = GiveBehavior(rawCollection[key]);
rawCollection[key] = behavior;
}
This is how I update the dictionary..
Is there anyway tat can be done via LINQ...
You could try the following:
List<string> keys = rawCollection.Keys.ToList();
keys.ForEach(key => { rawCollection[key] = GiveBehavior(rawCollection[key]); });
That should do it
rawCollection = rawCollection.ToDictionary(item => item.Key, item => GiveBehavior(item.Key));