New to REST API, and struggling a little.
I learned recently from here and here that I can receive a JSON describing an issue by calling a REST API of the form <JIRA_BASE_URL>/rest/api/2/issue/{issueIdOrKey}, e.g.:
curl -s -X GET -u super_user:super_password https://jira.server.com/rest/api/2/issue/TEST-12
Is there a way I can query many issues at once if I have a list of issue-ids, e.g. ["TEST-12", "TEST-13", "TEST-14"]?
I'm specifically interested in getting the summary field of each issue in my list of issue-ids. I.e. I'm trying to create a map of [issue-id:summary]. I currently do this by invoking the above curl command in a loop for each issue-id in my list. But I observe that this takes a long time, and I wonder if performance might be improved if there's a way to do a "bulk get" -- if such a feature exists.
Give the JQL Search API endpoint a try:
https://jira-url/rest/api/latest/search?fields=summary&jql=key%20in%20(TEST-12,%20TEST-13)
The fields parameter limits the fields returned, and the jql parameter lists out an array of the issue keys you'd like to retrieve.
The response looks like this:
{
...
"startAt": 0,
"maxResults": 50,
"total": 2,
"issues": [
{
...
"key": "TEST-12",
"fields": {
"summary": "TEST-12 Summary"
}
},
{
...
"key": "TEST-13",
"fields": {
"summary": "TEST-13 Summary"
}
}
]
}
I am designing a RESTful API for a mobile application I am working on. My problem is with large collections containing many items. I understand that a good practice is to paginate large number of results in a collection.
I have read the Facebook Graph API doc (https://developers.facebook.com/docs/graph-api/using-graph-api/v2.2), Twitter cursors doc (https://dev.twitter.com/overview/api/cursoring), GitHub API doc (https://developer.github.com/v3/) and this post (API pagination best practices).
Consider an example collection /resources in my API that contains 100 items named resource1 to resource100 and sorted descending. This is the response you will get upon a GET request (GET http://api.path.com/resources?limit=5):
{
"_links": {
"self": { "href": "/resources?limit=5&page=1" },
"last": { "href": "/resources?limit=5&page=7" },
"next": { "href": "/resources?limit=5&page=2" }
},
"_embedded": {
"records": [
{ resource 100 },
{ resource 99 },
{ resource 98 },
{ resource 97 },
{ resource 96 }
]
}
}
Now my problem is a scenario like this:
1- I GET /resources with above contents.
2- After that, something is added to the resources collection (say another device adds a new resource for this account). So now I have 101 resources.
3- I GET /resources?limit=5&page=2 as the initial response suggests will contain the next page of my results. The response would be like this:
{
"_links": {
"self": { "href": "/history?page=2&limit=5" },
"last": { "href": "/history?page=7&limit=5" },
"next": { "href": "/history?page=3&limit=5" }
},
"_embedded": {
"records": [
{ resource 96 },
{ resource 95 },
{ resource 94 },
{ resource 93 },
{ resource 92 }
]
}
}
As you can see resource 96 is repeated in both pages (Or similar problem may happen if a resource gets deleted in step 2, in that case one resource will be lost).
Since I want to use this in a mobile app and in one list, I have to append the resources of each API call to the one before it so I can have a complete list. But this is troubling. Please let me know if you have a suggestion. Thank you in advance.
P.S: I have considered timestamp like query strings instead of cursor based pagination, but that will make problems somewhere else for me. (let me know if you need more info about that.)
We just implemented something similar to this for a mobile app via a REST API. The mobile app passed an additional query parameter which represents a timestamp at which elements in the page should be "frozen".
So your first request would look something like GET /resources?limit=5&page=1&from=2015-01-25T05:10:31.000Z and then the second page request (some time later) would increment the page count but keep the same timestamp: GET /resources?limit=5&page=2&from=2015-01-25T05:10:31.000Z
This also gives the mobile app control if it wants to differentiate a "soft" page (preserving the timestamp of the request of page 1) from a "hard refresh" page (resetting the timestamp to the current time).
Why not just maintain a set of seen resources?
Then when you process each response you can check whether the resource is already being presented.
I have slideshows. Each slideshow consists of slide.
The following will return a list of ordered slides in a slideshow:
GET api/slideshows/123/slides:
{
{
slideId : "22",
name : "My slide"
},
{
slideId : "25",
name : "My second slide"
},
{
slideId : "26",
name : "Another slide"
}
}
I want to perform the following operation, for example:
Move slide 26 to the position after slide 22
What is a good way to expose such a request?
Either we can PUT the whole slides collection in a different order, but this will replace all the slide data if there happen to be more changes. Plus it could be a lot of data to transfer.
PUT api/slideshows/123/slides
Another option is to supply a moveAfter "operation":
POST api/slideshows/123/slides/26?action=moveAfter
body:
{
referenceId : "22"
}
I understand that this isn't entirely RESTful, but what other practical solutions exist?
I would do something like this: PUT api/slideshows/123/slides/26/position 22.
Btw. it is interesting. You can do it 2 ways:
every slide has a unique id, which does not depend on the order
the id is the same as the order index (or position) - in this case you have to update the whole collection after every move, because the server maintains the resource state and not the client, so it will be much slower.
I would go with the following design.
The key point here is that the slides for a slideshow are just an array of URIs pointing to the constituent slide resources. To reorder, add, or remove slides from a slideshow, you PATCH the slideshow resource with the new slides array.
Creating a slide is done independent of the slideshow that references it. Associations between slideshows and slides can only be changed by doing a PATCH on the slideshow resource.
Resource URIs do not nest deeply. That is a poor design choice that can come back to bite you later.
I illustrate it with a series of request-response pairs.
GET /slideshows/17
200 OK
{
"slideshow_id": 17,
"slides": [
"/slides/15",
"/slides/42",
"/slides/76",
"/slides/31"
]
}
POST /slides
{
"content": "..."
}
201 Created
Location: /slides/93
GET /slides/93
200 OK
{
"slide_id": 93,
"slideshow_association": null,
"content": "..."
}
PATCH /slideshows/17
{
"slides": [
"/slides/15",
"/slides/31"
"/slides/42",
"/slides/76",
"/slides/93"
]
}
204 No Content
GET /slides/93
200 OK
{
"slide_id": 93,
"slideshow_association": {
"slideshow": "/slideshows/17",
"index": 4,
"previous_slide": "/slides/76",
"next_slide": null
},
"content": "..."
}
Having 3 dropdown pickers in a web application. The web application uses a Restful service to populate pickers data.
The two first pickers get their values from something like /years and /colors. The third one should get its values depending on the settings of the two.
So it could be something like /models?year=1&color=red.
The question is, how to make this HATEOAS-compliant (so that the dev does not have to know the way he should create an url to get the models).
The root / gets me a number of links, such as:
{
"_links": {
"colors": "/colors",
"years": "/years",
"models": "???" }
}
What should be instead of ???? If there was some kind of template /models?color={color}&year={year}, the dev would have to create the url. Is this OK?
Or there could be a link to list of years on each color got from /colors and then a link to list of models on each year got from /years?color=red, but i'd have to first choose color, then populate years and then populate models. Any idea if i want to have the model dependent on both color and year, not just the year populated from color?
Is it even possible in this situation to make it hateoas-compliant?
I have not heard of HATEOAS before, but based on what I just read about it, it seems that it supposed to return links to where the consumer of the service can go forward in the "state machine".
In your case that would translate to the links being "function calls". The first two (/colors and /years) are functions that take no parameters (and return "something" at this point), while the third is a function call that takes two parameters: one that is a representation of a color, the other a year. For the first two having a simple URL will suffice for the link, but for the third, you need to include the parameter name/type information as well. Something like:
{
"_links": {
"colors": "/colors",
"years": "/years",
"models": {
"url": "/models",
"param1": {"color"}
"param2": {"year"}
}
}
}
Note: you can use the same layout as "models" for "colors" and "years" as well.
At this point the client knows what the URL to access the functions are and what the parameter (if any) names are to be passed to the function.
One more thing is missing: types. Although you could just use "string", it will not be obvious that the "color" parameter is actually a value from what "/colors" returns. You can be introducing a "type" Color that describes a color (and any functions that operate on a color: give a displayable name, HTML color code, etc.)
The "beefed up" signature becomes:
{
"_links": {
"colors": {
"url": "/colors",
"return": "/type/List?type=/type/Color"
},
"years": {
"url": "/years",
"return": "/type/List?type=/type/Integer"
},
"models": {
"url": "/models",
"param1": {
"name": "color",
"type": "/type/Color"
},
"param2": {
"name": "year",
"type": "/type/Integer"
}
"return": "/type/List?type=/type/Model"
}
}
}
Note: the path "/type" is used just to separate the types from functions, but is not necessary.
This will interchangeably and discoverably describe the functions, what parameters they take, and what values they are returning, so you can use the right value at the right place.
Of course implementing this on the service end will not be easy (especially with parameterized types, like "/type/List" -- think Generics in Java or templates in C++), but this is the most "safe" and "portable" way you can describe your interface to your clients.
I want to support pagination in my RESTful API.
My API method should return a JSON list of product via /products/index. However, there are potentially thousands of products, and I want to page through them, so my request should look something like this:
/products/index?page_number=5&page_size=20
But what does my JSON response need to look like? Would API consumers typically expect pagination meta data in the response? Or is only an array of products necessary? Why?
It looks like Twitter's API includes meta data: https://dev.twitter.com/docs/api/1/get/lists/members (see Example Request).
With meta data:
{
"page_number": 5,
"page_size": 20,
"total_record_count": 521,
"records": [
{
"id": 1,
"name": "Widget #1"
},
{
"id": 2,
"name": "Widget #2"
},
{
"id": 3,
"name": "Widget #3"
}
]
}
Just an array of products (no meta data):
[
{
"id": 1,
"name": "Widget #1"
},
{
"id": 2,
"name": "Widget #2"
},
{
"id": 3,
"name": "Widget #3"
}
]
ReSTful APIs are consumed primarily by other systems, which is why I put paging data in the response headers. However, some API consumers may not have direct access to the response headers, or may be building a UX over your API, so providing a way to retrieve (on demand) the metadata in the JSON response is a plus.
I believe your implementation should include machine-readable metadata as a default, and human-readable metadata when requested. The human-readable metadata could be returned with every request if you like or, preferably, on-demand via a query parameter, such as include=metadata or include_metadata=true.
In your particular scenario, I would include the URI for each product with the record. This makes it easy for the API consumer to create links to the individual products. I would also set some reasonable expectations as per the limits of my paging requests. Implementing and documenting default settings for page size is an acceptable practice. For example, GitHub's API sets the default page size to 30 records with a maximum of 100, plus sets a rate limit on the number of times you can query the API. If your API has a default page size, then the query string can just specify the page index.
In the human-readable scenario, when navigating to /products?page=5&per_page=20&include=metadata, the response could be:
{
"_metadata":
{
"page": 5,
"per_page": 20,
"page_count": 20,
"total_count": 521,
"Links": [
{"self": "/products?page=5&per_page=20"},
{"first": "/products?page=0&per_page=20"},
{"previous": "/products?page=4&per_page=20"},
{"next": "/products?page=6&per_page=20"},
{"last": "/products?page=26&per_page=20"},
]
},
"records": [
{
"id": 1,
"name": "Widget #1",
"uri": "/products/1"
},
{
"id": 2,
"name": "Widget #2",
"uri": "/products/2"
},
{
"id": 3,
"name": "Widget #3",
"uri": "/products/3"
}
]
}
For machine-readable metadata, I would add Link headers to the response:
Link: </products?page=5&perPage=20>;rel=self,</products?page=0&perPage=20>;rel=first,</products?page=4&perPage=20>;rel=previous,</products?page=6&perPage=20>;rel=next,</products?page=26&perPage=20>;rel=last
(the Link header value should be urlencoded)
...and possibly a custom total-count response header, if you so choose:
total-count: 521
The other paging data revealed in the human-centric metadata might be superfluous for machine-centric metadata, as the link headers let me know which page I am on and the number per page, and I can quickly retrieve the number of records in the array. Therefore, I would probably only create a header for the total count. You can always change your mind later and add more metadata.
As an aside, you may notice I removed /index from your URI. A generally accepted convention is to have your ReST endpoint expose collections. Having /index at the end muddies that up slightly.
These are just a few things I like to have when consuming/creating an API.
I would recommend adding headers for the same. Moving metadata to headers helps in getting rid of envelops like result , data or records and response body only contains the data we need. You can use Link header if you generate pagination links too.
HTTP/1.1 200
Pagination-Count: 100
Pagination-Page: 5
Pagination-Limit: 20
Content-Type: application/json
[
{
"id": 10,
"name": "shirt",
"color": "red",
"price": "$23"
},
{
"id": 11,
"name": "shirt",
"color": "blue",
"price": "$25"
}
]
For details refer to:
https://github.com/adnan-kamili/rest-api-response-format
For swagger file:
https://github.com/adnan-kamili/swagger-response-template
As someone who has written several libraries for consuming REST services, let me give you the client perspective on why I think wrapping the result in metadata is the way to go:
Without the total count, how can the client know that it has not yet received everything there is and should continue paging through the result set? In a UI that didn't perform look ahead to the next page, in the worst case this might be represented as a Next/More link that didn't actually fetch any more data.
Including metadata in the response allows the client to track less state. Now I don't have to match up my REST request with the response, as the response contains the metadata necessary to reconstruct the request state (in this case the cursor into the dataset).
If the state is part of the response, I can perform multiple requests into the same dataset simultaneously, and I can handle the requests in any order they happen to arrive in which is not necessarily the order I made the requests in.
And a suggestion: Like the Twitter API, you should replace the page_number with a straight index/cursor. The reason is, the API allows the client to set the page size per-request. Is the returned page_number the number of pages the client has requested so far, or the number of the page given the last used page_size (almost certainly the later, but why not avoid such ambiguity altogether)?
just add in your backend API new property's into response body.
from example .net core:
[Authorize]
[HttpGet]
public async Task<IActionResult> GetUsers([FromQuery]UserParams userParams)
{
var users = await _repo.GetUsers(userParams);
var usersToReturn = _mapper.Map<IEnumerable<UserForListDto>>(users);
// create new object and add into it total count param etc
var UsersListResult = new
{
usersToReturn,
currentPage = users.CurrentPage,
pageSize = users.PageSize,
totalCount = users.TotalCount,
totalPages = users.TotalPages
};
return Ok(UsersListResult);
}
In body response it look like this
{
"usersToReturn": [
{
"userId": 1,
"username": "nancycaldwell#conjurica.com",
"firstName": "Joann",
"lastName": "Wilson",
"city": "Armstrong",
"phoneNumber": "+1 (893) 515-2172"
},
{
"userId": 2,
"username": "zelmasheppard#conjurica.com",
"firstName": "Booth",
"lastName": "Drake",
"city": "Franks",
"phoneNumber": "+1 (800) 493-2168"
}
],
// metadata to pars in client side
"currentPage": 1,
"pageSize": 2,
"totalCount": 87,
"totalPages": 44
}
This is an interessting question and may be perceived with different arguments. As per the general standard meta related data should be communicated in the response headers e.g. MIME type and HTTP codes. However, the tendency I seem to have observed is that information related to counts and pagination typically are communicated at the top of the response body. Just to provide an example of this The New York Times REST API communicate the count at the top of the response body (https://developer.nytimes.com/apis).
The question for me is wheter or not to comply with the general norms or adopt and do a response message construction that "fits the purpose" so to speak. You can argue for both and providers do this differently, so I believe it comes down to what makes sense in your particular context.
As a general recommendation ALL meta data should be communicated in the headers. For the same reason I have upvoted the suggested answer from #adnan kamili.
However, it is not "wrong" to included some sort of meta related information such as counts or pagination in the body.
generally, I make by simple way, whatever, I create a restAPI endpoint for example "localhost/api/method/:lastIdObtained/:countDateToReturn"
with theses parameters, you can do it a simple request.
in the service, eg. .net
jsonData function(lastIdObtained,countDatetoReturn){
'... write your code as you wish..'
and into select query make a filter
select top countDatetoreturn tt.id,tt.desc
from tbANyThing tt
where id > lastIdObtained
order by id
}
In Ionic, when I scroll from bottom to top, I pass the zero value, when I get the answer, I set the value of the last id obtained, and when I slide from top to bottom, I pass the last registration id I got