I am writing my first java-backed webscript for Alfresco community edition. I am implementing document properties / preview service, and I take a parameter which is the cmis:objectId of the document in question. I'm having trouble getting started because I haven't been able to access the document based on the cmis id.
What is the best way to get a document (NodeRef?) based on the cmis:objectId when operating server-side in a web-script controller? I see Jeff Potts' great examples on how to implement web scripts, but the mixing of the Java API and CMIS concepts has me stuck. Should I just use the search service and find the object based on the cmis:objectId property? Any pointers appreciated.
Well, the answer is a little ugly, but hopefully this helps someone...
A good way to look up the NodeRef using an 'opaque' objectId should be to use CMISServices, obtained from the registry in your java backed web script, i.e.
docRef = registry.getCMISService().getLatestVersion(docIdStr, false);
Unfortunately, there's a bug in the Alfresco code (or so it seems to me, admittedly a bit of a newbie). The alfresco CMISServicesImpl.getLatestVersion() uses a getObject() method under the covers. That method takes an objectId String as a parameter, but then strips off the version information at the end (i.e. the ";1.0" part of the objectId) and then checks to see if the remaining string is a valid NodeRef. In doing so, it checks it against this pattern (in NodeRef.java):
private static final Pattern nodeRefPattern = Pattern.compile(".+://.+/.+");
If the validation fails, you get a CMISInvalidArgumentException, with a message that xxxxx "is not an object ID".
So, to make a long story short, when I call the web script using a parameter for the objectId like this:
29ea5a16-12a8-497d-aad3-f43969e8a672;1.0
I get the CMIS exception. But, if I call the method with an objectId parameter that looks like this:
workspace://SpacesStore/29ea5a16-12a8-497d-aad3-f43969e8a672;1.0
... then, the "CMIS" lookup succeeds and I get my desired NodeRef back. Of course, all that the CMIS services are doing under the covers is stripping off the ";1.0" from the object ID, treating it as a NodeRef string, and doing the lookup using that.
In other words, you can't do it the right way in 4.2. The best thing to do is as #Gagravarr says and tweak your own objectId string to turn it into a NodeRef. Hopefully it's fixed in 5.x.
Related
I am currently trying to create a custom IRI for one of my entities in API Platform.
I know there is page in the documentation describing how to use a custom IRI (https://api-platform.com/docs/core/identifiers/), but I can't get it working.
My entity uses a value object for the id (currently used for IRI) and also for the name (should be used for IRI). But the values themself are priviate and scalar in the entity.
API Platform seems to get the information what should be used as the identifier, from my XML Doctrine mapping. I already tried to overwrite it by usung annotations, attributues and YAML definitions. Without luck.
The returned error reads:
preg_match(): Argument #2 ($subject) must be of type string
(at this point it receives the value object instead of the actual value)
best regards,
spigandromeda
I solved my problem.
To explain the solution, I have to dig a little into API Platform response generation.
API platform generates an IRI for every entity it returns (colelction and item operation)
it's using the Symfony router go generate the URI
all the necessary information can draw API Platform from different sources (YAML, XML, annotations, attributes)
the information include the identifier(s) defined for the entities resource
API Platform gets the value for the identifier via Symfony property accessor
because the property accessor is using getters before accessing private properties via reflection, it will return the VO
an ordinary VO cannot be used by the Symfony URL generator to create the URL
As I explained, I am using a VO for my Id as well. So I tried to figure out why it was working with the Id VO but not with the name VO.
Simple answer: the Id VO implemented the __toString method and the name VO didn't. So the solution was to let the name VO implement this method as well.
It was interesing to dig into the internal process of API Platform, but I also feel a little stupid :D
I have a byte[] and wanna convert it to object parameter in asp.net.
byte[] version =98471574580;
and I have One method that wants "ObjectParametere version".I must convert byte[] version to
ObjectParametere.
The way to do this has a few steps that if you follow in future shoudl save you needing to ask this sort of question again.
1) Look at the documentation for the class you want to use. It is found here: http://msdn.microsoft.com/en-us/library/system.data.objects.objectparameter(v=vs.110).aspx googleing for "ObjectParameter" returns it as top hit for me. Google might have noticed me doing a lot of MSDN searches though and bumping them to the top so if in doubt try adding MSDN or c# to the search.
2) Look for how to create an instance of the object. This would usually be through constructors. Sometimes you may use static methods but constructors are usual and in fact there are two here we can consider.
3) Decide which constructor to use. One takes a name and a type. One takes a name and a value. Since we have a value this seems like the one to choose.
4) Call the constructor you have decided to use and assign it to a variable (or use it directly in your code). In this case the syntax would be var objParam = new ObjectParameter("version", version);.
Some of these steps might be short circuited. For example if you are programming in Visual Studio then typing new ObjectParameter( should then offer intellisense help on what constructors are available, saving the need to look the documentation up online.
I am working on struts 2.0 . I am designing a web application.
I am using Jasper Report in my application. I want to access the *.jrxml files in my action class. I don't want to give hard coded path to the files. So to get the path dynamically I googled it and got the solution that I can get the path using getRealPath() method. But I found two implementation of doing this:
Using HttpSession to get object of ServletContext and using the getRealPath() method of the ServletContext object.
Like this:
HttpSession session = request.getSession();
String realPath = session.getServletContext().getRealPath("/");
The second approach to do it directly using the static method getServletContext() of ServletActionContext. And then we can get the real path of the application using the getRealPath() method.
Like this:
String realPath = ServletActionContext.getServletContext().getRealPath("/");
Please tell me, is there any difference between the above two and also please tell me whether there is any other way to get the path?
Neither is "better", really, and I'd argue that neither is particularly good, either.
I might try getting the context path in an initialization servlet and stick it into the application context, then make your action(s) ApplicationAware and retrieve the value from the map.
This has the added benefit of aiding testability and removing the static references in the action.
That said, I see zero reason to go through the extra mechanics of your first approach: it adds a lot of noise for no perceivable benefit; I'm not even sure why it wuld be considered.
I'd also be a little wary of tying your actions to a path like this unless there's a real need, what's the specific use? In general you shouldn't need to access intra-app resources by their path.
I am porting a legacy application to Symfony2 and I am struggling because routing doesn't include query string parameters. Some quick examples: Suppose you have a search page for books where you can filter results based on criteria:
http://www.bookstore.com/books?author=Stephen+King&maxPrice=20
The nice thing about query string parameters in a case like this is you can have any number of filters, use the ones you want for any given request, and not crowd the URL with filters you're not using.
Let's say we rewrote the routing for the above query using the Symfony2 routing component. It might look like this:
http://www.mybookstore.com/book/any_title/stephen%20king/any_release_date/max_price_20/any_min_price/any_format/any_category
Even not taking into account how arbitrarily long an unclean that URL is I still don't think it is as intuitive because each 'segment' of that route is not a key value pair but instead just a value (e.g. author=Stephen+King > /stephen%20king/).
You can of course access query string parameters in the controller by passing the Request object into the action method (e.g. indexAction(Request $request) {) but then validating them and passing them into other parts of the application becomes a hassle (i.e. where I find myself now). What if you are using the Knp Menu Bundle to build your sidebar and you want parts to be marked as .current based on query string parameters? There is no functionality for that, just functionality to integrate with Symfony2 routes.
And how to validate that your query string parameters are acceptable? I am currently looking at validating them like a form to then pass them into the database to generate a query. Maybe this is the way the Symfony2 team envisioned handling them? If so I'd just really like to know why. It feels like I'm fighting the application.
I ended up actually asking Fabien this question at Symfony Live San Francisco 2012. There was another talk at the same conference in regards to this question and I will share with you the slides here:
http://www.slideshare.net/Wombert/phpjp-urls-rest#btnNext
Basically in the slides you can see that the author agrees with me in that query string parameters should be used for filtering. What they should not be used for is determining a content source. So a route should point to a product (or whatever) and query string parameters should then be used in your controller to apply whatever logic you require to filter that content source (as per Fabien).
I ended up creating an entity in my application that I bind all my query string parameters to and then manipulate, much the same way forms are handled. In fact when you think about it it's basically the same thing.
Like in Symfony1, query strings are independent from the route parameters.
If you have a path defined as #Route("/page/{id}", name="single_page"), you can create a path in your view like this:
{{ path('single_page', { id: 3, foo: "bar" }) }}
The resulting URL will be /page/3?foo=bar.
this is one of the few moments I couldn't find the same question that I have at this place so I'm trying to describe my problem and hope to get some help an ideas!
Let's say...
I want to design a RESTful API for a domain model, that might have entities/resources like the following:
class Product
{
String id;
String name;
Price price;
Set<Tag> tags;
}
class Price
{
String id;
String currency;
float amount;
}
class Tag
{
String id;
String name;
}
The API might look like:
GET /products
GET /products/<product-id>
PUT /prices/<price-id>?currency=EUR&amount=12.34
PATCH /products/<product-id>?name=updateOnlyName
When it comes to updating references:
PATCH /products/<product-id>?price=<price-id>
PATCH /products/<product-id>?price=
may set the Products' Price-reference to another existing Price, or delete this reference.
But how can I add a new reference of an existing Tag to a Product?
If I wanted to store that reference in a relational database, I needed a relationship table 'products_tags' for that many-to-many-relationship, which brings us to a clear solution:
POST /product_tags [product: <product-id>, tag: <tag-id>]
But a document-based NoSQL database (like MongoDB) could store this as a one-to-many-relationship for each Product, so I don't need to model a 'new resource' that has to be created to save a relationship.
But
POST /products/<product-id>/tags/ [name: ...]
creates a new Tag (in a Product),
PUT /products/<product-id>/tags/<tag-id>?name=
creates a new Tag with <tag-id> or replaces an existing
Tag with the same id (in a Product),
PATCH /products/<product-id>?tags=<tag-id>
sets the Tag-list and doesn't add a new Tag, and
PATCH /products/<product-id>/tags/<tag-id>?name=...
sets a certain attribute of a Tag.
So I might want to say something link this:
ATTACH /products/<product-id>?tags=<tag-id>
ATTACH /products/<product-id>/tags?tag=<tag-id>
So the point is:
I don't want to create a new resource,
I don't want to set the attribute of a resource, but
I want to ADD a resource to another resources attribute, which is a set. ^^
Since everything is about resources, one could say:
I want to ATTACH a resource to another.
My question: Which Method is the right one and how should the URL look like?
Your REST is an application state driver, not aimed to be reflection of your entity relationships.
As such, there's no 'if this was the case in the db' in REST. That said, you have pretty good URIs.
You talk about IDs. What is a tag? Isn't a tag a simple string? Why does it have an id? Why isn't its id its namestring?
Why not have PUT /products/<product-id>/tags/tag_name=?
PUT is idempotent, so you are basically asserting the existance of a tag for the product referred to by product-id. If you send this request multiple times, you'd get 201 Created the first time and 200 OK the next time.
If you are building a simple system with a single concurrent user running on a single web server with no concurrency in requests, you may stop reading now
If someone in between goes and deletes that tag, your next put request would re-create the tag. Is this what you want?
With optimistic concurrency control, you would pass along the ETag a of the document everytime, and return 409 Conflict if you have a newer version b on the server and the diff, a..b cannot be reconciled. In the case of tags, you are just using PUT and DELETE verbs; so you wouldn't have to diff/look at reconciliation.
If you are building a moderately advanced concurrent system, with first-writer-wins semantics, running on a single sever, you can stop reading now
That said, I don't think you have considered your transactional boundaries. What are you modifying? A resource? No, you are modifying value objects of the product resource; its tags. So then, according to your model of resources, you should be using PATCH. Do you care about concurrency? Well, then you have much more to think about with regards to PATCH:
How do you represent the diff of a hierarchial JSON object?
How do you know what PATCH requests that conflict in a semantic way - i.e. we may not care about DELETEs on Tags, but two other properties might interact semantically.
The RFC for HTTP PATCH says this:
With PATCH, however, the enclosed entity contains a set of
instructions describing how a resource currently residing on the
origin server should be modified to produce a new version. The PATCH
method affects the resource identified by the Request-URI, and it also
MAY have side effects on other resources; i.e., new resources may be
created, or existing ones modified, by the application of a PATCH.
PATCH is neither safe nor idempotent as defined by [RFC2616], Section
9.1.
I'm probably going to stop putting strange ideas in your head now. Comment if you want me to continue down this path a bit longer ;). Suffice to say that there are many more considerations that can be done.