public class Model {
}
public class SuperclassDTO {
private boolean funny = true;
public boolean isFunny() {
return funny;
}
public boolean setFunny(boolean f) {
this.funny = f;
}
}
public class SubclassDTO extends SuperclassDTO {
}
new SubclassDTO().isFunny() //returns true
SubclassDTO dto = binder.bindFromBusinessObject(SubclassDTO.class, new Model());
dto.isFunny(); //returns false!!!!
Isn't this weird? Model class does not have a "funny" field but somehow dto is bind with a wrong value. First I thought jDTO required "getFunny" convention, so it couldn't read the value and just set it "false" but changing the getter name to "getFunny" does not resolve the issue, plus I'm not allowed to modify SuperclassDTO. How can I bind the correct value?
Jdto version 1.4 by the way...
The behavior you're experiencing is a "side effect" of the convention over configuration approach. All the fields on the DTO are configured unless you mark them as transient, either by using the #DTOTransient annotation or the transient configuration on the XML file. If a configured field does not have a corresponding field on the source bean, it will be set with default values and that is the reason why you're experiencing this behavior.
You have some options to overcome this issue:
Add the #DTOTransient annotation to the DTO.
Since you're not able to modify the DTO, you could configure it through XML.
Use Binding lifecycle to Restore the value. By adding code on the subclass.
You might as well submit a bug report on the jDTO issue tracker on github.
Related
#Self
Resource resource;
#Inject
#Named(value = "key")
private String key;
#PostConstruct
protected void init() throws PersistenceException {
ResourceResolver rr = resource.getResourceResolver();
ModifiableValueMap map = resource.adaptTo(ModifiableValueMap.class);
String value = fetchValue();
map.put("key", value);
rr.commit();
}
I'm trying to give the property "Key" the default value "value". Unfortunately it has to be returned by a function and can't be simply set to a primitive type with #Default(..). The above code seems to do nothing, the value of the component is not updated. I'm pretty new to the whole AEM stack so I feel like I might be going at this the wrong way.
Please remove revolver.commit() line . Unless you’ve obtained the resolver using the system user , you don’t have to commit it . You can simple use Session session=resolver.adaptTo(Session.class) and then say session.save ().
Did you try setting the value of the field key to the value you were trying to fetch instead of modifying the JCR property value directly?
#Inject
private String key;
#PostConstruct
protected void init() {
if (StringUtils.isBlank(key)) {
key = fetchValue();
}
}
public String getKey() {
return key;
}
On a different note, the #Self injector is discouraged due to reasons mentioned here.
Apparently I was using the #PostConstruct wrong: I thought it would trigger upon creation of the node, but the trigger is instead related to the rendering of the component.
To set values in a sling model when rendering a component is an anti-pattern. The repository shouldn't be modified when the page is being rendered. If you need to have default values when component node is created use cq:template feature of AEM. This copies over properties defined in the template when a new component instance is created. [template != page template in this context]
Its usage has been answered in this question AEM DefaultValue written to JCR
Additional reference :
http://blogs.adobe.com/experiencedelivers/experience-management/defaults-in-your-component/
In my submodule, I have:
public class CustomerRepository : ICustomerRepository
{
private readonly IDBEngine _dbEngine;
[CanBeNull] private readonly string _overriddenDebugEmail;
[Obsolete("Use the other constructor")]
public CustomerRepository(IDBEngine dbEngine)
{
_dbEngine = dbEngine;
_overriddenDebugEmail = null;
}
// ReSharper disable once UnusedMember.Global
public CustomerRepository(IDBEngine dbEngine, IDebugConstants debugConstants)
{
_dbEngine = dbEngine;
_overriddenDebugEmail = debugConstants.OverridingDebugEmail;
}
...
The problem is, when I simply update the submodule without implementing IDebugConstants, I get the following runtime error:
Error activating IDebugConstants
No matching bindings are available, and the type is not self-bindable.
I want Ninject to bind to the Obsolete constructor if IDebugConstants is not implemented. But it refuses to because of the obsolete attribute.
In theory I could remove the Obsolete attribute, but I want it to show that that code should no longer exist once all old programs using the submodule have been updated.
Is there some way to make Ninject ignore the Obsolete attribute?
Or am I going about this entirely wrong somehow?
You can do this by adding the [Inject] attribute to your [Obsolete] constructor.
The reason for this is how the constructor scoring is implemented. Specifically this section of the Score method:
if (directive.Constructor.HasAttribute(this.settings.InjectAttribute))
{
return int.MaxValue;
}
if (directive.Constructor.HasAttribute(typeof(ObsoleteAttribute)))
{
return int.MinValue;
}
You will see that if the constructor has the [Obsolete] attribute then it is given the minimum possible score. But prior to that, if the constructor has the [Inject] attribute then it will be given the highest possible score.
This doesn't help in the specific case you mentioned where you want a conditional binding when IDebugConstants is not implemented, but it does answer "Is there some way to make Ninject ignore the Obsolete attribute?"
I've been modeling a domain for a couple of days now and not been thinking at all at persistance but instead focusing on domain logic. Now I'm ready to persist my domain objects, some of which contains IEnumerable of child entities. Using RavenDb, the persistance is 'easy', but when loading my objects back again, all of the IEnumerables are empty.
I've realized this is because they don't have any property setters at all, but instead uses a list as a backing field. The user of the domain aggregate root can add child entities through a public method and not directly on the collection.
private readonly List<VeryImportantPart> _veryImportantParts;
public IEnumerable<VeryImportantPart> VeryImportantParts { get { return _veryImportantParts; } }
And the method for adding, nothing fancy...
public void AddVeryImportantPart(VeryImportantPart part)
{
// some logic...
_veryImportantParts.Add(part);
}
I can fix this by adding a private/protected setter on all my IEnumerables with backing fields but it looks... well... not super sexy.
private List<VeryImportantPart> _veryImportantParts;
public IEnumerable<VeryImportantPart> VeryImportantParts
{
get { return _veryImportantParts; }
protected set { _veryImportantParts = value.ToList(); }
}
Now the RavenDb json serializer will populate my objects on load again, but I'm curious if there isn't a cleaner way of doing this?
I've been fiddeling with the JsonContractResolver but haven't found a solution yet...
I think I've found the root cause of this issue and it's probably due to the fact that many of my entities were created using:
protected MyClass(Guid id, string name, string description) : this()
{ .... }
public static MyClass Create(string name, string description)
{
return new MyClass(Guid.NewGuid(), name, description);
}
When deserializing, RavenDb/Json.net couldn't rebuild my entities in a proper way...
Changing to using a public constructor made all the difference.
Do you need to keep a private backing field? Often an automatic property will do.
public IList<VeryImportantPart> VeryImportantParts { get; protected set; }
When doing so, you may want to initialize your list in the constructor:
VeryImportantParts = new List<VeryImportantPart>();
This is optional, of course, but it allows you to create a new class and start adding to the list right away, before it is persisted. When Raven deserializes a class, it will use the setter to overwrite the default blank list, so this just helps with the first store.
You certainly won't be able to use a readonly field, as it couldn't be replaced during deserialization. It might be possible to write a contract resolver or converter that fills an existing list rather than creating a new one, but that seems like a rather complex solution.
Using an automatic property can add clarity to your code anyway - as it is less confusing whether to use the field or the property.
(or "Using LocationInterceptionAspect and IInstanceScopedAspect together")
Using Postsharp I'm trying to inject a property into a target class using 'IntroduceMember' and then using the 'OnGetValue' functionality of LocationInterceptionAspect dynamically give it a value on inspection.
Originally I thought that I'd need two separate aspects, one for the field injection and one for the location interception but managed to combine the two by implementing the IInstanceScopedAspect interface and inheriting from LocationInterceptionAspect.
The problem is that if I set a breakpoint I will see the property that's been injected, but if I set another breakpoint in the OnGetValue method (that gets fired for each property on the class) I can't see it...
Here's some sample code:
[Serializable]
class DALDecoratorWrapper : LocationInterceptionAspect, IInstanceScopedAspect
{
public override void OnGetValue(LocationInterceptionArgs args)
{
if (args.LocationName == "Type")
{
args.Value = "computed value here";
}
args.ProceedGetValue();
}
[IntroduceMember(OverrideAction = MemberOverrideAction.OverrideOrFail)]
public String Type { get; set; }
I was also hoping there was a better way of doing this than overriding OnGetValue as that's called for each getter where really I want to only target the getter of the property that's been injected
Cheers
I have a base class ReportElement which has type property:
public abstract class ReportElement {
private ReportElementType type;
public ReportElementType getType() {
return type;
}
public void setType(ReportElementType type) {
this.type = type;
}
}
ReportElementType is just an enum with specified code and i18nKey properties for each element. I have a couple of subclasses of ReportElement, each of them introducing their own properties. One of them is Plot:
public class Plot extends ReportElement {
public Plot() {
setType(ReportElementType.PLOT);
}
private Collection<Parameter> parameters = new ArrayList<Parameter>();
public Collection<Parameter> getParameters() {
return parameters;
}
}
On some page I needed to display a collection of different ReportElement instances, so I just used struts2 select tag:
<s:select list="myElements" listKey="type.code" listValue="type.i18nKey" size="20"/>
This worked like a charm for every element except for Plot instaces. Instead of invoking getType().getCode() or getType().getI18nKey() plain toString() was invoked on every instance of Plot! After several hours of fun debugging I noticed that during tag evaluation Plot's getParameters() method is called! So it seems struts was trying to evaluate type.code and type.i18nKey using getParameters() method! Failing to do that it ignored the existence of the properties, that I have clearly specified for usage!
After renaming getParameters to a kind of odd name like getParamms the problem gone. Also the problem hasn't occured when using iterator tag together with property tag instead of select tag.
Does anyone have an idea WHY struts select tag uses parameters property of my bean, when I have clearly specified what property should be used? Is it some "cool" feature or a bug?
P.S. I use struts 2.2.3.1
The argument used in all the FreeMarker templates representing a tag's parameters is called parameters. By providing a parameters property that takes precedence, S2 was unable to get to the object on the stack containing the tag's parameters.
It's neither a cool feature nor a bug, it's just how the templates are implemented. Checking the template source may have saved the few hours of debugging.
Found corresponding issue in struts JIRA: https://issues.apache.org/jira/browse/WW-3268
2.3 is specified as fix version.