Paging Metadata in Response Body
by Kris Borchers
I've hit one small snag. If the paging metadata is returned in the body, it would probably be useful for the developer to be able to specify a "paging container" and/or a "results container" since each of those pieces of information would probably be encapsulated from the other in any sane server implementation. I would suggest something like metadataContainer and dataContainer with defaults of "paging" and "data" as defaults but I am totally flexible on those.
Thoughts?
13 years
Server Side: Paging API with Metadata and Links (was: Re: Paging Demo)
by Matthias Wessendorf
Looking at the PR for the demo ([1]) ,I am a bit surprised that
classes like "Links.java" or "Metadata.java" are part of the demo
code.
I thought that the metadata/header informations on the response, like:
```
AG-Paging-Offset: 1
AG-Paging-Limit: 4
AG-Paging-Total: 4
AG-Links-First: cars?offset=0&limit=4
AG-Links-Previous: cars?offset=0&limit=4
AG-Links-Next: cars?offset=2&limit=4
AG-Links-Last: cars?offset=3&limit=4
```
are applied by the framework. Of course, the "cars" in there is app
specific, but this information could be read out of the actual route
(/cars).
Not sure, but... if all the time we (end user) needs to (re)impl.
these things... it could be a bit annoying.
IMO the problem would be:
- if we add a dependency on the params into our client libraries, we
pretty much build against a "demo API". Which is odd...
I thought these "metadata details" are offered by the framework.
-M
[1] https://github.com/aerogear/aerogear-controller-demo/pull/19
On Sun, Jan 13, 2013 at 12:09 PM, Daniel Bevenius
<daniel.bevenius(a)gmail.com> wrote:
> I've updated the demo and think I've included all the requests.
> * Pre-populate the database upon deployment of demo.
> * Use 'offset/limit' instead of 'page/perPage'.
> * Use 'AG-' prefix for headers.
>
> Let me know if you are missing anything, or would like something done in a
> different way.
>
> Use case
>
> The example is using /cars as the resource to interact with.
>
> The following route has been added to the demo:
>
> route()
> .from("/cars")
> .on(RequestMethod.GET)
> .produces(MediaType.JSON)
> .to(Cars.class).get(param("offset", "0"), param("limit", "-1"));
>
> From this we can see that there are two optional parameters, offset and
> limit. If these are not specified all cars will be returned.
>
> Getting a page of Cars
>
> curl -i --header "Accept: application/json"
> "http://controllerdemo-danbev.rhcloud.com/aerogear-controller-demo/cars?of..."
>
> The request will return:
>
> HTTP/1.1 200 OK
> Content-Type: application/json;charset=UTF-8
> Content-Length: 160
> AG-Paging-Offset: 0
> AG-Paging-Limit: 4
> AG-Paging-Total: 4
> AG-Links-Next: cars?offset=1&limit=4
> AG-Links-Last: cars?offset=3&limit=4
> [
> {"color":"Green","brand":"Audi","id":1},
> {"color":"White","brand":"Audi","id":2},
> {"color":"Black","brand":"Audi","id":3},
> {"color":"Black","brand":"BMW","id":4}
> ]
>
> Getting the next page of Cars
>
> To get the next page you can follow the next link:
>
> curl -i --header "Accept: application/json"
> "http://controllerdemo-danbev.rhcloud.com/aerogear-controller-demo/cars?of..."
>
> HTTP/1.1 200 OK
> Content-Type: application/json;charset=UTF-8
> Content-Length: 166
> AG-Paging-Offset: 1
> AG-Paging-Limit: 4
> AG-Paging-Total: 4
> AG-Links-First: cars?offset=0&limit=4
> AG-Links-Previous: cars?offset=0&limit=4
> AG-Links-Next: cars?offset=2&limit=4
> AG-Links-Last: cars?offset=3&limit=4
> [
> {"color":"Green","brand":"BMW","id":5},
> {"color":"Red","brand":"Ferrari","id":6},
> {"color":"White","brand":"Ferrari","id":7},
> {"color":"Pink","brand":"Ferrari","id":8}
> ]
>
> Get all Cars
>
> curl -i --header "Accept: application/json"
> "http://controllerdemo-danbev.rhcloud.com/aerogear-controller-demo/cars"
>
> This request will return:
>
> [
> {"color":"Green","brand":"Audi","id":1},
> {"color":"White","brand":"Audi","id":2},
> {"color":"Black","brand":"Audi","id":3},
> {"color":"Black","brand":"BMW","id":4},
> {"color":"Green","brand":"BMW","id":5},
> {"color":"Red","brand":"Ferrari","id":6},
> {"color":"White","brand":"Ferrari","id":7},
> {"color":"Pink","brand":"Ferrari","id":8},
> {"color":"White","brand":"Golf","id":15},
> {"color":"Brown","brand":"Lada","id":16},
> {"color":"Orange","brand":"Mazda","id":14},
> {"color":"Pink","brand":"Mini","id":13},
> {"color":"Gray","brand":"Nissan","id":11},
> {"color":"Yello","brand":"Opel","id":10},
> {"color":"Blue","brand":"Scoda","id":9},
> {"color":"Red","brand":"Volvo","id":12}
> ]
>
> Get a single Car
>
> curl -i --header "Accept: application/json"
> "http://controllerdemo-danbev.rhcloud.com/aerogear-controller-demo/cars/1"
>
> The request will return:
>
> {"color":"Green","brand":"Audi","id":1}
>
>
>
> On 12 January 2013 11:08, Daniel Bevenius <daniel.bevenius(a)gmail.com> wrote:
>>
>> Great, lets go with 'AG-' prefix then.
>>
>>
>>
>>
>> On 11 January 2013 18:24, Douglas Campos <qmx(a)qmx.me> wrote:
>>>
>>>
>>> On 11/01/2013, at 15:10, Kris Borchers <kris(a)redhat.com> wrote:
>>> > I guess what I meant is I'm not specifically +1 for X- prefix but just
>>> > some sort of prefix in general. It just makes it easier for devs when
>>> > looking through headers to see what is being sent. Even something like AG-
>>> > or AeroGear- would be better IMO than no prefix.
>>>
>>> d'oh, +1 - thought I've typed it…
>>>
>>> AG- looks nicer - less bandwidth ;)
>>>
>>> -- qmx
>>> _______________________________________________
>>> aerogear-dev mailing list
>>> aerogear-dev(a)lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/aerogear-dev
>>
>>
>
>
> _______________________________________________
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> aerogear-dev(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/aerogear-dev
>
--
Matthias Wessendorf
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13 years
Web Linking and Paging
by Kris Borchers
Since we decided to use the Web Linking standard (RFC 5988) for controller's paging implementation, it was also decided to remove the "offset" and "limit" from the response headers since that info is in the links. Though I think it could be useful to still include those headers, I think it can be ok without them.
That being said, it got me to thinking about those links. The question that occurred to me was whether or not those links included all other query params that were used to generate this paged result. I would really hope that it did, otherwise these links would be pretty much useless since they would link to a paged result of unfiltered items. I just want to verify the following items and make sure we're all on the same page:
1) Controller should include any and all filtering parameters that were used to generate the paged result set in the web linking headers.
2) If other servers for some reason do not include that information, that is not a problem our clients have to deal with. We should be free to assume that if the server is use web linking as its paging implementation, it is providing the necessary information in that link to get to the next or previous page in that filtered set.
13 years
Pagination Requirements Spec
by Daniel Bevenius
Hi,
we've created the following gist[1] to specify our requirements for
pagination. We can discuss this on the mailing list and then update the doc
as we go along. This will later be turned into a page under the spec
section of the site.
Nothing has been decide yet even if it might read like it has in the
document.
[1] https://gist.github.com/4537431
13 years, 1 month
