What is the best way to enforce required fields, field lengths, and other validation on put and post requests for WebAPI based OData requests?
I have had some success with [Required] attributes, but in the past we have used [DataContract] and [DataMember(IsRequired=true), on the entity classes, but that doesn't seem to cause the ModelState.IsValid to return false when a field with the [DataMember(IsRequired=true) is left off the json posted to the request.
It appears that the proper solution is to add both the [DataMember(IsRequired=true)] and the [Required] attributes to each data item you wish to enforce as required.
Related
My model looks like
public class Template
{
Id
Title
List<Field> Fields
}
The “Field” Entity contains information like Name, Caption, Type (TextBox/Select/Radio), Options, and validation rules (Range, Required, string length). How to set Field Properties from HTML helper??
The standard validation in MVC is based on DataAnnotations, but I wants to validate (Both client and Server Side) the form dynamically based on Field Metadata which is dynamic and configurable. How to set Field Properties from HTML helper so that I can use it in controller for validation?
i am building my the model using ODataModelBuilder, i am trying to create navigation property however in the metadata i dont see any foreginkey indication, in my solution i am not using EF, so there is no foreignKey attribute, is it possible to add it by code?
As you clarified in your comment, the reason you want to add foreign key information is because your client application is not including related entities when you query the main entity. I don't think foreign keys are the problem here.
As an example, I'll use two entity types: Customer and Order. Every Customer has some number of associated Orders, so I have a navigation property on Customer called Orders that points to a collection of Orders. If I issue a GET request to /MyService.svc/Customers(1), the server will respond with all of the Customer's information as well as URLs that point to the related Order entities*. I won't, by default, get the data of each related Order within the same payload.
If you want a request to Customers(1) to include all of the data of its associated Orders, you would add the $expand query option to the request URI: /MyService.svc/Customers(1)?$expand=Orders. Using the WCF Data Services client (DataServiceContext), you can do this with .Expand():
DataServiceQuery<Customer> query = context.Customers.Expand("Orders");
However, WebAPI OData doesn't currently support $expand (the latest nightly builds do though, so this will change soon).
The other approach would be to make a separate request to fill in the missing Order data. You can use the LoadProperty() method to do this:
context.LoadProperty(customer, "Orders");
The LoadProperty approach should work with WebAPI as it stands today.
I know this doesn't answer your original question, but I hope addresses your intent.
*In JSON, which is the default format for WebAPI OData services, no links will show up on the wire, but they are still there "in spirit". The client is expected to be able to compute them on its own, which the WCF Data Services Client does.
My validation requirements for a the fields in a form are contained in an external table so that they can be updated without altering and rebuilding the code.
I have approximatley 100 fields with a mixture of validation requirements - range, required, regular expression and dependency on other fields. One example is date range validation. A date of birth field requires a date range which is between -10 years and -50 years of the current date.
I have read around the subject but have not identified a pattern for the complete solution.
I am using Visual Studio 2010 with MVC 3 and Entity Framework.
Any help with this would be gratefully received. Thanks in advance.
In a simple level I think you can still use the built-in Data-Annotations validation attributes to does the validation and for that you should map the validation rules stored in the table to the attributes.
I think all you have to do is create a custom model validation provider by inheriting the class ModelValidatorProvider. This class contains a single method called GetValidators that returns the collection validators for that model.
You have to implement the GetValidators method and in there you have to make a database call to get the validation rules for the model from the database (or from cache?) and convert them into ModelValidators. You could still use the built-in DataAnnotationsModelValidator to do the validations.
I would suggest you to look into the source code of DataAnnotationsModelValidatorProvider that will give you all the information. In that class what they are doing is basically iterating all the validation attributes applied to the model properties and converting them into ModelValidators through adapters and factories. In your case instead of attributes they are stored as records in tables and I don't think much work will be there.
My requirement is to create a custom data annotation attribute for my project. The requirement is to validate the min/ max length of a specific product from the database, which will be retrieved from the database using the ProductID. I have a dynamic page for each product where there are two fields called max length & min length. User inputs the values in these two fields which needs to be validated from the database. Product table contains all the products & one will be selected by passing a productId.
Please suggest some pointers to implement the above.
Thanks in advance.
This validation you can do only in the server side and not in client, so I see two options.
Remote Validation - You can use remote validation when you want to perform the validation and show the error message through ajax.
IValidatableObject - By implementing this interface in the class you can do both the validations at the same time and return all the validation error messages as a collection. By this way the validation will happen after the form is normally submitted.
Suppose i have a 'View' for filling up form for renting a DVD , as per MVC architecture , either of 'Controller' or 'Model', who is supposed to validate the form data?
Thanks
You validation should be in Model section of MVC.
As models have various fields, only models can know what combination of inputs make that model valid. It's not just about whether a field is blank, or the input of that field matches some pattern, but sometimes this is a combination of field inputs, or the model's relationship to other models that determine the valid state.
All 3 are usually involved in the validation process if you follow the typical flow.
The model defines validation attributes such as the required or stringlength attributes. The controller checks the validation state of the model via ModelState.IsValid and makes decisions accordingly. The view may additional provide client-side validation for those same attributes. Don't rely solely on js to validate the form.
My suggestion would be to validate in the view with some form of validation binding, and then again in the model before persisting to any data store.