I have a Restlet (v2.1.1) component that is using a ServerResource to process HTTP GET requests.
I would like to put filters and/or routers into the component so that they can do some processing before the request gets to the ServerResource.
I have been searching the Internet for an example of doing this, as well as reading the "Restlet in Action" book. I have discovered something interesting:
There are plenty of examples of how to set up a ServerResource within a component.
There are plenty of examples of how to create and set up filters and routers.
Unfortunately, search as I might, through the book and on the Internet, I cannot find an example of using both!
According to the book and the tutorials on the Internet, we should be able to create a component, set up a ServerResource in the component, and use a filter to preprocess requests that go to the ServerResource. None of the documentation anywhere seems to tell us exactly how to do this.
Am I misreading everything? Is there really no way to put filters or routers in components with ServerResources? Or have I missed some document somewhere that provides a real example of how to do this?
Could someone please either provide a simple example or provide a link to an example of doing this?
Thanks...
You need to attach the filter to the router and then attach the ServerResource to the filter using the method setNext(Class<? extends ServerResource> targetClass):
Filter myFilter = new MyFilter(getContext());
myFilter.setNext(MyServerResource.class);
router.attach("/test", myFilter);
Now you can preprocess using the filter's beforeHandle(Request request, Response response) method. If you return CONTINUE in this method, the filter will pass the request to the ServerResource.
Related
I am designing my first REST API.
Suppose I have a (SOAP) web service that takes MyData1 and returns MyData2.
It is a pure function with no side effects, for example:
MyData2 myData2 = transform(MyData myData);
transform() does not change the state of the server. My question is, what REST call do I use? MyData can be large, so I will need to put it in the body of the request, so POST seems required. However, POST seems to be used only to change the server state and not return anything, which transform() is not doing. So POST might not be correct? Is there a specific REST technique to use for pure functions that take and return something, or should I just use POST, unload the response body, and not worry about it?
I think POST is the way to go here, because of the sheer fact that you need to pass data in the body. The GET method is used when you need to retrieve information (in the form of an entity), identified by the Request-URI. In short, that means that when processing a GET request, a server is only required to examine the Request-URI and Host header field, and nothing else.
See the pertinent section of the HTTP specification for details.
It is okay to use POST
POST serves many useful purposes in HTTP, including the general purpose of “this action isn’t worth standardizing.”
It's not a great answer, but it's the right answer. The real issue here is that HTTP, which is a protocol for the transfer of documents over a network, isn't a great fit for document transformation.
If you imagine this idea on the web, how would it work? well, you'd click of a bunch of links to get to some web form, and that web form would allow you to specify the source data (including perhaps attaching a file), and then submitting the form would send everything to the server, and you'd get the transformed representation back as the response.
But - because of the payload, you would end up using POST, which means that general purpose components wouldn't have the data available to tell them that the request was safe.
You could look into the WebDav specifications to see if SEARCH or REPORT is a satisfactory fit -- every time I've looked into them for myself I've decided against using them (no, I don't want an HTTP file server).
I'm trying to figure out if FeathersJS suits my needs. I have looked at several examples and use cases. FeathersJS uses a set of request methods : find, get, create, update, patch and delete. No other methods let alone custom methods can be implemented and used, as confirmed on this other SO post..
Let's imagine this application where users can save their app settings. Careless of following method conventions, I would create an endpoint describing the action that is performed by the user. In this case, we could have, for instance: /saveSettings. Knowing there won't be any setting-finding, -creation, -updating (only some -patching) or -deleting. I might also need a /getSettings route.
My question is: can every action be reduced down to these request methods? To me, these actions are strongly bound to a specific collection/model. Sometimes, we need to create actions that are not bound to a single collection and could potentially interact with more than one collection/model.
For this example, I'm guessing it would be translated in FeathersJS with a service named Setting which would hold two methods: get() and a patch().
If that is the correct approach, it looks to me as if this solution is more server-oriented than client-oriented in the sense that we have to know, client-side, what underlying collection is going to get changed or affected. It feels like we are losing some level of freedom by not having some kind of routing between endpoints and services (like we have in vanilla ExpressJS).
Here's another example: I have a game character that can skill-up. When the user decides to skill-up a particular skill, a request is sent to the server. This endpoint can look like POST: /skillUp What would it be in FeathersJS? by implementing SkillUpService#create?
I hope you get the issue I'm trying to highlight here. Do you have some ideas to share or recommendations on how to organize the API in this particular framework?
I'm not an expert of featherJs, but if you build your database and models with a good logic,
these methods are all you need :
for the settings example, saveSettings corresponds to setting.patch({options}) so to the route settings/:id?options (method PATCH) since the user already has some default settings (created whith the user). getSetting would correspond to setting.find(query)
To create the user AND the settings, I guess you have a method to call setting.create({defaultOptions}) when the user CREATE route is called. This would be the right way.
for the skillUp route, depends on the conception of your database, but I guess it would be something like a table that gives you the level/skills/character, so you need a service for this specific table and to call skillLevel.patch({character, level})
In addition to the correct answer that #gui3 has already given, it is probably worth pointing out that Feathers is intentionally restricting in order to help you create RESTful APIs which focus on resources (data) and a known set of methods you can execute on them.
Aside from the answer you linked, this is also explained in more detail in the FAQ and an introduction to REST API design and why Feathers does what it does can be found in this article: Design patterns for modern web APIs. These are best practises that helped scale the internet (specifically the HTTP protocol) to what it is today and can work really well for creating APIs. If you still want to use the routes you are suggesting (which a not RESTful) then Feathers is not the right tool for the job.
One strategy you may want to consider is using a request parameter in a POST body such as { "action": "type" } and use a switch statement to conditionally perform the desired action. An example of this strategy is discussed in this tutorial.
I've been trying to make use of service.getNavigation() method, but apparently the Request URI is too long which causes this error:
Request-URI Too Long
The requested URL's length exceeds the capacity limit for this server.
Is there a spartacus config that can resolve this issue?
Or is this supposed to be handled in the cloud (ccv2) config?
Not sure which service are you talking about specifically and what data are you passing there. For starters, please read this: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/414
Additionally it would benefit everyone if you could say something about the service you're using and the data you are trying to pass/get.
The navigation component is firing a request for all componentIds. If you have a navigation with a lot of (root?) elements, the maximum length of HTTP GET request might be too long for the given client or server.
The initial implementation of loading components was actually done by a POST request, but the impression was that we would not need to support requests with so many components. I guess we were wrong.
Luckily, the legacy POST based request is still in the code base, it's OccCmsComponentAdapter.findComponentsByIdsLegacy.
The easiest way for you to use this code, is to provide a CustomOccCmsComponentAdapter, that extends from OccCmsComponentAdapter. Then you can override the findComponentsByIds method and simply call the super.findComponentsByIdsLegacy and pass in a copy of the arguments.
A more cleaner way would be to override the CmsComponentConnector and directly delegate the load to the adapter.findComponentsByIdsLegacy. I would not start here, as it's more complicated. Do a POC with the first suggested approach.
I have some difficulties customizing the Aikau faceted search page on Alfresco, which may be more a matter of lack of my knowledge about dojo/AMD.
What I want to do is to replace the document details page URL by a download URL.
I extended the Search Results Widget to include my own custom module :
var searchResultWidget = widgetUtils.findObject(model.jsonModel, "id", "FCTSRCH_SEARCH_RESULT");
if(searchResultWidget) {
searchResultWidget.name = "mynamespace/search/CustomAlfSearchResult";
}
I understand search results URLs are rendered this way :
AlfSearchResult module => uses SearchResultPropertyLink module => mixins _SearchResultLinkMixin renderer => bring the "generateSearchLinkPayload" function => renders URLs depending on the result type
I want to override this "generateSearchLinkPayload" function but I can't figure out what is the best way to do that.
Thanks in advance for the help !
This answer assumes you're able to use the latest version of Aikau (at the time of writing this is 1.0.61). Older versions might require slightly different overriding...
In order to do this you're going to need to override the createDisplayNameRenderer function of AlfSearchResult in your CustomAlfSearchResult widget. This will allow you to create an extension of alfresco/search/SearchResultPropertyLink.
If you want to take advantage of the the download capabilities provided by the alfresco/services/DocumentService for downloading both documents and folders (as a zip) then you're going to want to change both the publishTopic and publishPayload of the SearchResultPropertyLink.
You should extend the getPublishTopic and generateSearchLinkPayload functions. For the getPublishTopic function you'll want to change the return value to be "ALF_SMART_DOWNLOAD" (there are constants available for these strings in the alfresco/core/topics module). This topic can be used to tell the DocumentService to take care of figuring out if the node is a folder or document and will make an XHR request for the full node metadata (in order to get the contentUrl attribute that is not included in the data returned by the Search API.
You should extend the generateSearchLinkPayload function so that for document or folder types the payload contains the attribute nodes that is a single array where the object is the search result object that you wish to download.
I would recommend that you call this.inherited first to get the default payload and only update it for documents and folders.
Hopefully that all makes sense - if not, add a comment and I'll try to provide further assistance!
This is the answer for 1.0.25.2 - unfortunately it's not quite so straightforward...
You still need to extend the alfresco/search/AlfSearchResult widget, however this time you need to extend the postCreate function (remembering to call this.inherited(arguments)). It's not possible to stop the original alfresco/search/SearchResultPropertyLink widget from being created... so it will be necessary to find it and destroy it.
The widget is not assigned to a variable, so it will be necessary to find it using dijit/registry. Use the byNode function from dijit/registry to find the widget assigned to this.nameNode and then call destroy on it (be sure to pass the argument true to preserve the DOM). However, you will then need to empty the DOM node so that you can start again...
Now you need to add in your extension to alfresco/search/SearchResultPropertyLink. Unfortunately, because the smart download capability is not available you'll need to do more work. The difference here is that you'll need to make an XHR request to retrieve the full node metadata in order to obtain the contentURL. It's possible to publish a request to the DocumentService(via the "ALF_RETRIEVE_SINGLE_DOCUMENT_REQUEST" topic). However, you need to be aware that having the XHR step will not allow you to then proceed with the download as is. Instead you'll need to use an iframe download solution, I'd suggest you take a look at the changes in the pull request we recently made to solve this problem and backport them into your own solution.
I need to implement a custom event handler, which should for example handle URIs like:
- SomeAppName://SomeDomainClassName/ID to fetch a record from a database table
or
- SomeAppName://SomeControllerName/PushView/SomeAdditionalOptions to push a view controller and set additional options, for example this could be a calendar view which should be focused to show the calendar at a certain date.
I have been searching for existing REST frameworks, but so far I didn't figure how any exising framework could allow me to define formats for URIs and map them to local classes, actions, whatever it will be.
How could I 1) define and interpret REST like URIs and 2) map them to local actions or objects, without reinventing the wheel (e.g. inheriting from RESTKit)?
Or should I end up to write my own parser? In that case, pointers to good REST like URI lex/flex are welcome.
What I was looking for is called an URL router in Ruby worlds. There exist a few also for Objective C, more or less useful.
I ended up to write a custom URL Router, that is like ruby URL routers just split into basically two components (router and route). For the Router part (the mapper and URL dispatcher so to say) I looked at TTURLMap, which is part of Three20, but threw away 90% of code and changed the action handling to fit my needs. It has lot's of boilerpate code, but basically was what I needed for getting an idea for the router.
For the particular route handling I use SOCKit, which seems great and has well tested code.
Now I can for example have a local function hello which takes two params to show some values passed as URL:
Roter *router = [[Router alloc] init];
[router map:#"soc://:ident/:saySomething" toInstance:self with:#selector(hello:sayWhat:)];
[router dispatch:#"soc://3/hi"];
I'll add blocks as well, but for most cases selectors work well, because SOCKit passes them the actual values for basic parameter types (no need to use parse the dictionary with values from the URL).