I have a Spring Security User class which has a unique constraint for username and email. In a Command class I imported all constraints from this class with "importFrom User". All constraints work as expected EXCEPT the unique ones.
However when saving the User the unique constraints get validated and errors are shown. But it would be nice if they get validated BEFORE saving like all other constraints.
UPDATE
I added this to the controller:
user.errors.fieldErrors.each {
command.errors.rejectValue(it.getField(), it.getCode())
}
Seems like a dirty workaround, but it works.
Good question #Chris, and your solution is best since the goal of sharing constraints between domain classes and command objects is to avoid duplicating validation logic.
I'll just add that to avoid duplicating field errors and to handle nested field paths in domain objects, something like the following might be necessary.
def save(EntityCreateCommand cmd) {
def entity = new Entity(cmd.properties)
def someAssociation = new Something(cmd.properties)
entity.someAssociation = someAssociation
entity.validate()
entity.errors.fieldErrors.each {
def fieldName = it.field.split("\\.").last()
def flattenedCodes = cmd.errors.getFieldErrors(fieldName).codes.flatten()
if(cmd.hasProperty(fieldName) && (!flattenedCodes.contains(it.code))) {
cmd.errors.rejectValue(fieldName,
"entityCreateCommand.${fieldName}.${it.code}")
}
}
if(cmd.errors.hasErrors()) {
error handling stuff...
} else {
business stuff...
}
}
I had problems with unique constraint before, so I made a custom validator in my command object to test and see if it's unique:
Command Object:
class wateverCommand{
....
String username
static constraints = {
username validator:{value, command ->
if(value){
if(User.findByUsername(value){
return 'wateverCommand.username.unique'
}
}
}
}
}
within your messages.properties add a custom error message:
wateverCommand.username.unique The username is taken, please pick a new username
I agree the unique constraint doesn't always seem to import properly. Since I like to avoid clutter in the constraint body I like the one liner approach:
validator: {value, command -> (User.findByUsername(value) ? false : true ) }
Then in your message.properties it would be:
accountCommand.username.validator.error=That username already exists
Related
I try to validate a nested domain class instance on a command object.
Having the following command object
package demo
import grails.databinding.BindingFormat
class SaveEventCommand {
#BindingFormat('yyyy-MM-dd')
Date date
Refreshment refreshment
static constraints = {
date validator: { date -> date > new Date() + 3}
refreshment nullable: true
}
}
And having the following domain class with its own constraints
package demo
class Refreshment {
String food
String drink
Integer quantity
static constraints = {
food inList: ['food1', 'food2', 'food3']
drink nullable: true, inList: ['drink1', 'drink2', 'drink3']
quantity: min: 1
}
}
I need when refreshment is not nullable the command object validates the date property and check the corresponding restrictions in refreshment instance
For now try with this code in the controller:
def save(SaveEventCommand command) {
if (command.hasErrors() || !command.refreshment.validate()) {
respond ([errors: command.errors], view: 'create')
return
}
// Store logic goes here
}
Here through !command.refreshment.validate() I try to validate the refresh instance but I get the result that there are no errors, even when passing data that is not correct.
Thank you any guide and thank you for your time
I typically just include some code that will use a custom validator to kick off validation for any property that is composed of another command object. For example:
thePropertyInQuestion(nullable: true, validator: {val, obj, err ->
if (val == null) return
if (!val.validate()) {
val.errors.allErrors.each { e ->
err.rejectValue(
"thePropertyInQuestion.${e.arguments[0]}",
"${e.objectName}.${e.arguments[0]}.${e.code}",
e.arguments,
"${e.objectName}.${e.arguments[0]}.${e.code}"
)
}
}
})
This way it's pretty clear that I want validation to occur. Plus it moves all the errors up into the root errors collection which makes things super easy for me.
Two things I could think of:
Implement grails.validation.Validateable on your command object
What happens when you provide an invalid date? Can you see errors while validating?
I'm having a validation issue very similar to what is described here
https://schneide.wordpress.com/2010/09/20/gorm-gotchas-validation-and-hasmany/
but with an important difference that I don't have (or want) a List<Element> elements field in my domain. My code is
class Location {
static hasMany = [pocs: LocationPoc]
Integer id
String address
String city
State state
String zip
...
static mapping = {
...
}
static constraints = {
def regEx = new RegEx()
address blank: true, nullable: true, matches: regEx.VALID_ADDRESS_REGEX
city blank: true, nullable: true
state blank: true, nullable: true
zip blank: true, nullable: true
...
}
}
however, if I save/update a location with a bunk POC (point of contact), I get some wild errors. I would like to validate the POC's when I save/update a location, but I'm not exactly sure how. I've tried a few variations of
pocs validator: {
obj -> obj?.pocs?.each {
if (!it.validate()) {
return false
}
}
return true
}
to no avail. Is this possbile without creating a new field on my domain, List<LocationPoc> pocs?
You're close. The issue is you need to target the property you want to validate instead of using the object reference. It should look like this:
pocs validator: { val, obj, err ->
val?.each {
if (!it.validate()) return false
}
}
Validation doesn't automatically cascade through hasMany associations. In order to get free validation, the other side of the relationship needs to belong to Location.
You didn't include your LocationPOC class, but if you modify
Location location
to
static belongsTo = [location: Location]
Then you will get cascading validation when you save your Location object.
If you can't set the belongsTo property on LocationPoc, and need to use the custom validator, the syntax is a bit different than the answer above.
pocs validator: {val, obj ->
val?.inject true, {acc,item -> acc && item.validate()}
}
the three arguement version of validate expects you to add errors to the errorCollection. https://grails.github.io/grails2-doc/2.5.6/ref/Constraints/validator.html
Plus using a return statement inside of .each doesn't work like the above example. It just exits the closure and starts the next iteration. The validator from the other answer was just returning val (the result of val.each is just val)
You need to spin through the entire collection looking for non valid options.
I have a View Model called SignUp with the EmailAddress property set like this:
[Required]
[DuplicateEmailAddressAttribute(ErrorMessage = "This email address already exists")]
public string EmailAddress { get; set; }
and the custom validator looks like this:
public class DuplicateEmailAddressAttribute : ValidationAttribute
{
public override bool IsValid(object value)
{
PestControlContext _db = new PestControlContext();
int hash = value.ToString().GetHashCode();
if (value == null)
{
return true;
}
if (_db.Users.Where(x => x.EmailAddressHash == hash).Count() > 0)
return false;
else
return true;
}
}
The problem I'm having is that if the user leaves the email address field blank on the sign up form the application is throwing a null reference exception error (I think it's looking for "" in the database and can't find it). What I don't understand is why this isn't being handled by the Required attribute - why is it jumping straight into the custom validator?
The Required attribute would have resulted in an error being added to the model state. It will not short-circuit the execution though. The framework continues to run other validators for the simple reason that all the errors about the request need to be sent out in a single shot. Ideally, you wouldn't want the service to say something is wrong to start with and when the user re-submits the request after making a correction, the service comes back and say some other thing is wrong and so on. It will be an annoyance, I guess.
The NullReferenceException is thrown because value.ToString() is called before the check against null. As you need the hash variable only after the check, you can solve this by reordering the statements:
if (value == null)
{
return true;
}
int hash = value.ToString().GetHashCode();
In addition, you could also move the PestControlContext after the check against null and use a using statement to dispose of it properly.
As also #Baldri pointed out, each validator can add Error messages and all of them are run, even if a previous one already signaled the data to be invalid. Furthermore, I'd not rely on that the validations are run in the order that you specify when marking the property with the attributes (some frameworks implement their own attribute ordering mechanism in order to assert that the order is deterministic, e.g. priorities or preceding attributes).
Therefore, I suggest reordering the code in the custom validator is the best solution.
I'm running into an issue with Entity Framework code-first in MVC3. I'm hitting this exception:
An object with the same key already exists in the ObjectStateManager.
The ObjectStateManager cannot track multiple objects with the same
key.
This is addressed many times on SO, but I'm having trouble utilizing any of the suggested solutions in my situation.
Here is a code sample:
FestORM.SaleMethod method = new FestORM.SaleMethod
{
Id = 2,
Name = "Test Sale Method"
};
FestContext context = new FestContext();
//everything works without this line:
string thisQueryWillMessThingsUp =
context.SaleMethods.Where(m => m.Id == 2).Single().Name;
context.Entry(method).State = System.Data.EntityState.Modified;
context.SaveChanges();
EDITED to clarify: I am attempting to update an object that already exists in the database.
Everything works fine without the query noted in the code. In my application, my controller is instantiating the context, and that same context is passed to several repositories that are used by the controller--so I am not able to simply use a different context for the initial query operation. I've tried to remove the entity from being tracked in the ObjectStateManager, but I can't seem to get anywhere with that either. I'm trying to figure out a solution that will work for both conditions: sometimes I will be updating an object that is tracked by the ObjectStateManager, and sometimes it will happen to have not been tracked yet.
FWIW, my real repository functions look like this, just like the code above:
public void Update(T entity)
{
//works ONLY when entity is not tracked by ObjectStateManager
_context.Entry(entity).State = System.Data.EntityState.Modified;
}
public void SaveChanges()
{
_context.SaveChanges();
}
Any ideas? I've been fighting this for too long...
The problem is that this query
string thisQueryWillMessThingsUp =
context.SaleMethods.Where(m => m.Id == 2).Single().Name;
brings one instance of the SaleMethod entity into the context and then this code
context.Entry(method).State = System.Data.EntityState.Modified;
attaches a different instance to the context. Both instances have the same primary key, so EF thinks that you are trying to attach two different entities with the same key to the context. It doesn't know that they are both supposed to be the same entity.
If for some reason you just need to query for the name, but don't want to actually bring the full entity into the context, then you can do this:
string thisQueryWillMessThingsUp =
context.SaleMethods.Where(m => m.Id == 2).AsNoTracking().Single().Name;
If what you are tying to do is update an existing entity and you have values for all mapped properties of that entity, then the simplest thing to do is to not run the query and just use:
context.Entry(method).State = System.Data.EntityState.Modified;
If you don't want to update all properties, possibly because you don't have values for all properties, then querying for the entity and setting properties on it before calling SaveChanges is an acceptable approach. There are several ways to do this depending on your exact requirements. One way is to use the Property method, something like so:
var salesMethod = context.SaleMethods.Find(2); // Basically equivalent to your query
context.Entry(salesMethod).Property(e => e.Name).CurrentValue = newName;
context.Entry(salesMethod).Property(e => e.SomeOtherProp).CurrentValue = newOtherValue;
context.SaveChanges();
These blog posts contain some additional information that might be helpful:
http://blogs.msdn.com/b/adonet/archive/2011/01/29/using-dbcontext-in-ef-feature-ctp5-part-4-add-attach-and-entity-states.aspx
http://blogs.msdn.com/b/adonet/archive/2011/01/30/using-dbcontext-in-ef-feature-ctp5-part-5-working-with-property-values.aspx
The obvious answer would be that your not actually saving the method object to the database before you call:
//everything works without this line:
string thisQueryWillMessThingsUp = context.SaleMethods.Where(m => m.Id == 2).Single().Name;
However, I think perhaps this is just a bit a code you left out.
What if you make your entities inherit from an abstract class ie.
public abstract class BaseClass
{
public int Id { get; set; }
}
Then update your Repository to
public class Repository<T> where T : BaseClass
{
.....
public void Update(T entity)
{
_context.Entry(entity).State = entity.Id == 0 ? System.Data.EntityState.Added : System.Data.EntityState.Modified;
}
}
Also you might want to not set the ID of your SaleMethod and let it be generated by the database. Problem could also be because SaleMethod Object in the database has Id of 2 and then you try to add another SaleMethod object with Id 2.
The error you see stems from trying to add another SaleMethod object with ID of 2 to the ObjectStateManager.
I have Domain class and in that for a particular field of type String, it accepts alphanumeric values,i need a validation in the format it should accept only AB12-QW-1 (or) XY-12 values. how can i validate the field.
Please suggest the solution.
Thanks.
Assume your domain class looks like this
class Foo {
String bar
}
If you can define a regex that matches only the legal values, you can apply the constraint using:
class Foo {
String bar
constraints = {
bar(matches:"PUT-YOUR-REGEX-HERE")
}
}
Alternatively, if you can easily list all the legal values, you can use:
class Foo {
String bar
constraints = {
bar(inList:['AB12-QW-1', 'XY-12'])
}
}
If neither of these solutions will work, then you'll likely need to write a custom validator method
You could use a custom validator:
class YourDomain {
String code
static constraints = {
code( validator: {
if( !( it in [ 'AB12-QW-1', 'XY-12' ] ) ) return ['invalid.code']
})
}
}
However, your explanation of what codes are valid is a bit vague, so you probably want something else in place of the in call
[edit]
Assuming your two strings just showed placeholders for letters or numbers, the following regexp validator should work:
constraints = {
code( matches:'[A-Z]{2}[0-9]{2}-[A-Z]{2}-[0-9]|[A-Z]{2}-[0-9]{2}' )
}
And that will return the error yourDomain.code.matches.invalid if it fails