I am using the D2RQ Language to create the mapping file. I have a class Persona with this defination:
# Table persone
map:Persona a d2rq:ClassMap;
d2rq:dataStorage map:database;
d2rq:uriPattern "persona/##persona.cognome_persona##";
d2rq:class prova_rules_M:Persona;
.
I would like to create a data_property called "anni_persona" for this class. How can I do? Can anyone help me with the syntax?
Thank you!
Properties don't "belong" to classes in RDF or OWL. Instead, properties may have domains and ranges, which specifies that the subject or object of a triple with the property belongs to a certain class or datatype. E.g., if we say that the domain of hasName is Agent, then whenever we see "x hasName {something}", then we can infer that "x rdf:type Agent". It sounds like you're trying to say there is a property anni_persona, and that its domain is Persona. That's just a matter of asserting anni_persona rdfs:domain Persona somewhere.
Now, to get values from the database table into RDF data, I think that you'll just want to take a look at section 6 in the documentation:
6. Adding properties to resources (d2rq:PropertyBridge).
A d2rq:PropertyBridge relates a database column to an RDF property.
Property bridges are used to attach properties to the RDF resources
created by a class map. The values of these properties are often
literals, but can also be URIs or blank nodes that relate the resource
to other resources, e.g. the value of a paper's :author property could
be a URI representing a person.
If the one of the columns used in a property bridge is NULL for some
database rows, then no property is created for the resources
corresponding to these rows.
Based on the examples in that documentation, it looks like you'd end up with something like:
map:AnniPersona a d2rq:PropertyBridge ;
d2rq:belongsToClassMap map:Persona ;
d2rq:property :anni_persona ;
d2rq:column "Persone.Anni" .
Related
In glade it is possible to set an unique ID to an object. In the code one can obtain a pointer to this object by searching for it's "glade ID" via gtk_builder_get_object().
However for my current use-case I just want to read out this ID from an GObject. What's the API to do so ?
You can't. The builder ID is stored in the builder internally, not in the GObject.
The reason for this is that IDs must be unique per builder, which would be impossible to enforce if you were able to get and set them via some GObject API.
You could use gtk_widget_get_name() to identify an object.
It is possible using Gtk.Buildable.get_name(object). This method will return the Glade object id.
This snippet will print all object ids in your Glade XML:
builder = Gtk.Builder()
builder.add_from_file("my-window.glade"))
for obj in builder.get_objects():
print(Gtk.Buildable.get_name(obj))
As stated by #ptomato it's seems not possible.
I found that in that line in the documentation:
All the fields in the GObject structure are private to the
implementation and should never be accessed directly.
But you can circumvent it because at one point in your code you were refering to it by the id that you typed in (or the code you wrote type in) so you just need to store it at that point. And link it somehow (with a variable or a data structure) to the name of the variable holding the object.
This is more of a generalized question as I have yet to write the code for the question I am asking. Before I get started writing the code I wanted to make sure I am on the right track and possibly getting suggestions for better ways to do what I want to do. Basically right now I have a core data model setup in a way that I think is correct for what I am trying to do and just need some guidance on a very specific part of the code but want to make sure overall I created it correctly.
The first part to the question is more of a clarification on how relationships work in core data. Right now I have 5 entities and to make sure I have the correct idea on how it works I will use a few examples to make sure I am on the right track.
So lets save I have an entity I called name. Within that Name entity that contains only a name attribute. Next I have an entity that has classes, that each have a boolean of true or false to determine which class it is. These 2 are related in a inverse relationship of Name entity having a to one relationship and the Classes having a to many relationship because multiple names can have multiple classes but each name can only have 1 class. If I am right on this one that means I full understand core data relationships!
Now the second part of the question is related to the booleans in the class. I have the Class entity which is like I said a boolean containing a true false set as default to false. When the user selects one of the class buttons before presenting the popover where they actually give the name of the class selected it saves the boolean to true then passes that data over to the popover Name view controller. I am very unsure as to how to do this as it isn't a widely asked question on here nor have I been able to find any info through researching. I am one of those people who needs to actually learn by clear examples....any help with this would be appreciated! Sorry I don't have any example code for this.
The first part seems correct. The ManagedObject of your Class CoreDataObject should have an NSSet property which will contain the names (as the Class can have multiple names)
For the second part, Core Data uses objects. When you 'get' the data from Core Data it will be a (probably extended) NSManagedObject (named Class in our case). You can send this object as a parameter just as you would do with any other object and use it as you would use any other object :-). For example looping over de NSSet Names
func iterateOverNames(someClass: Class) {
for name: Name in someClass.names {
// do stuff
}
}
You can check these links for more information:
https://realm.io/news/jesse-squires-core-data-swift/
https://developer.apple.com/library/ios/documentation/Cocoa/Reference/CoreDataFramework/Classes/NSManagedObject_Class/index.html
I am trying to create an auto-generated GUID property on all cq:PageContent nodes. This will be similar to the jcr:uuid property, but will be persisted with content promotion/replication/package installs (whereas the jcr:uuid for a content item changes between different environments).
I am trying to determine how AEM/JCR generates the jcr:uuid property on node creation. The CND defining the property is:
[mix:referenceable]
mixin
- jcr:uuid (string) mandatory autocreated protected initialize
I've tried defining my GUID property in a similar manor, specifying the autocreated and initialize attributes, but this did not result in auto-generation of the property.
Could anybody point me to the source of the jcr:uuid's generation?
As an aside, I asked a related question on the Adobe Community Forum: http://help-forums.adobe.com/content/adobeforums/en/experience-manager-forum/adobe-experience-manager.topic.5_ciot.html/forum__bnxr-i_am_tryingtocreat.html
You don't mention which version of AEM (so whether you're dealing with Jackrabbit or Oak), but the mechanism turns out to be basically the same.
When assigning a default value, there are a few hard-coded system property names that get special treatment (jcr:uuid being one of them). If the name of the property being assigned a default value doesn't match any of the special cases, it falls back the static list of default values from the property definition (e.g. listed in the CND file).
In summary, it looks like you cannot piggy-back on this mechanism to assign your own dynamic default value for an arbitrary property. You would need to implement your own event listener or something.
Jackrabbit: See the implementation of setDefaultValues and computeSystemGeneratedPropertyValues
Oak: See the implementation of TreeUtil autoCreateProperty
I am trying to implement a distributed cache with spring-memcached. The docs suggest that
to use an object as the key I need to have a method in my domain class with #CacheKeyMethod
annotation on it.
But the problem is I am using the same domain class in different scenarios and the key to be generated in each case has different logic. For examples for a User class one of the scenarios requires the key to be unique in terms of city and gender and but in the other case it requires to be unique in terms of the user's email, it's essentially what your lookup is based on.
Although a user's email would determine the city and gender, so I can use email as the key in first case as well but that would mean separate cache entries for each user while the cached data would be same as long as the gender and city are same, which is expected to increase the hit ratio by a huge margin(just think how many users you can expect to be males from bangalore).
Is there a way I could define different keys. Also it would be great if the logic of
generating the key could be externalised from the domain class itself.
I read the docs and figured out that something called CacheKeyBuilder and/or CacheKeyBuilderImpl could do the trick but I couldn't understand how to proceed.
Edit..
ok.. I got one clue! What CacheKeyBuliderImpl does is, it calls the generateKey method on defaultKeyProvider instance which looks for #cachekeyannotation on the provided domain class's methods and executes the method found to obtain the key.
So replacing either the CacheKeyBuilderImpl with custom Impl or replacing KeyProvider's default implementation within CacheKeyBuilderImpl with yours might do the trick... but the keyprovider reference is hardwired to DefaultKeyProvider.
Can anybody help me implement CacheKeyBuilder(with respect to what different methods do;the documentation doesn't clarify it) and also how do I inject it to be used instead of ususal CacheKeyBuilderImpl
Simple Spring Memcached (SSM) hasn't be designed to allow such low level customization. As you wrote one of way is to replace CacheKeyBuilderImpl with own implementation. The default implementation is hardwired but it can be easily replaces using custom simplesm-context.xml configuration.
As I understand your question, you want to cache your User objects under different keys depends on use case. It's supported out of the box because by default SSM uses method argument to generate cache key not the result.
Example:
#ReadThroughMultiCache(namespace = "userslist.cityandgenre", expiration = 3600
public List<User> getByCityAndGenre(#ParameterValueKeyProvider(order = 0) String city, #ParameterValueKeyProvider(order = 1) String genre) {
// implementation
}
#ReadThroughSingleCache(namespace = "users", expiration = 3600)
public User getByEmail(#ParameterValueKeyProvider String email) {
// implementation
}
In general the #CacheKeyMethod is only used to generate cache key if object that contains the method is passed as a parameter to the method and the parameter is annotated by #ParameterValueKeyProvider
I have an simple object that has a name
public class Foo {
private String name
}
Each user on the site may have up to 10 Foo's associated with them. Within this context, when a new Foo is created, I would like to validate that there isn't another foo associated with the same user that already exists.
I could Create a custom Bean Validator But annotations require the paramaeters to be defined during compilation. How would I then pass across the names of the existing Foos?
As suggested in various places, I could use EL expressions as an alternative way to pick up the data. This feels like using a sledgehammer to crack a nut. It also brings in a whole bunch of potential issues to consider least of all being ease of testing.
I could do class-wide validation using a boolean field
#AssertTrue(message="Name already exists")
public boolean isNameUnique() {
return (existingNames.contains(name));
}
But the validation message would not show up next to the name field. It is a cosmetic issue and this can be a backup plan. However, its not ideal.
Which brings me to the question:
Is there a simple way to write a Bean Validator that can check the value against a collection of values at the field level and meet the following restrictions ?
Previous values determined at runtime
Not using things like EL expressions
Field level validation instead of class level.
EDIT in reponse to Hardy:
The Foo class is an entity persisted within a database. They are picked up and used through a DAO interface.
I could loop through the entities but that means plugging the DAO into the validator and not to mention that the I would need to write the same thing again if I have another class that too has this constraint.
It would help to see how you want to use the Foo class. Can you extend your example code? Are they kept in a list of Foo instances. A custom constraint seems to be a good fit. Why do you need to pass any parameters to the constraints. I would just iterate over the foos and check whether the names are unique.