I'm looking for the hash equivalent of this question: How to pass array query params to AWS API Gateway?
Basically, I want to set up query parameters that look like this:
example.com?color[background]=yellow&color[foreground]=black
When I try to create a query parameter called color[background] in the API Gateway console, I get the following error message:
Invalid mapping expression specified: Validation Result: warnings : [], errors : [Parameter name should be a non-empty alphanumeric string]
I've also tried setting up a color query param and then passing various "hashes" to it. Here's what I've tried passing into this parameter:
{"background" => 123, "foreground" => "abc"} and removing the spaces
{"background" : 123, "foreground" : "abc"} and removing the spaces
{background:123,foreground:abc}
They all result in a request that is some form of example.com?color=%7Bbackground:123,foreground:abc%7D with the hash that I pass coming after the =.
Any ideas? Is this bad practice for query string parameters anyways, and should I stick with simple params?
Since there isn't a standard defined to pass in complex data structures like arrays or maps via the query string, API Gateway does not attempt to to interpret or parse the query string as anything other than simple key-value string pairs.
If you want to pass in and transform complex types it's best to do so in the body of a POST or PUT request where you can leverage JSON and API Gateway's powerful body mapping templates feature.
Alternatively, if you must stick with query string parameters, then you must either:
Collapse your data structure to be simple key value pairs as suggested by Michael -sqlbot above, or
Passthrough the raw query string to your backend lambda or http integration where it can parsed as you please. See this post for more details on how to do that.
Related
I am using golang and want to store some data in Amazon DynamoDB in set of strings format SS. It is possible to store data but when I want to pull it back on unmarshaling stage it unmarshal every property except of prop that contain set of strings. Structure that I use to unmarshal in has []string type of that property. I saw that dynamodbattribute have some specific methods for unmarshaling like UnmarshalMap and so one but I didn't find specific method for SS. Can someone give me an advise?
Currently I have created custom unmarshaler following that example:
https://docs.aws.amazon.com/sdk-for-go/api/service/dynamodb/dynamodbattribute/#UnixTime.UnmarshalDynamoDBAttributeValue
but I still think that I am doin smth wrong because it should be easier way to parse set of strings...
I have a SearchDomain on AWS CloudSearch. I know all the defined facets names.
I would like to build a web query form to use it, but I want to add my categories values (facets) on the side, like it is done on Amazon webstore
The only way I have to get facets values is to make a query (params query) and in the answer will contain facets linked to my query results.
Is there a way to fetch all the facet.FIELD possible values to build the query form ?
If not (as read here), how to design a form using facets ?
You could also use the matchall keyword in a structured query. Also, since you don't need the results you can pass size=0 so you only get the facets which will reduce latency.
/2013-01-01/search?q=matchall&q.parser=structured&size=0&facet.field={sort:'count',size:100}
I wanted to fetch the List of Entities from database at Front end.
So I have written POST REST HTTP call in Spring MVC.
But I read the HTTP documentation which says whenever you have to retrieve data from database prefer GET call.
So, Is it there is any I can replace the POST call to GET call from angular JS and pass list of Integers.
But, GET HTTP has many drawbacks like : the length of URL is limited.Considering the case where we have to fetch 1000 entities from database.
Please suggest me the possible way to get the entities or write GET REST API in Spring MVC for list of integers(refers to ID's of Entities).
For Example : Consider there are 100 books in book table, But I want only few books, say id : 5,65,42,10,53,87,34,23.
Thats why I am passing this List of Id's in a List of Integer in POST call.
Currently stuck how to convert this to GET call. In Short, how to pass List of Integers through GET REST call.
I prefer a variant through HTTP path variable for your problem, because of in REST ideology a resource ID is passed after a resource name 'http://../resource/id' and HTTP parameters are used for filtering.
Through HTTP parameters
If you need to pass your ids through HTTP parameters, see an axample below:
Here is your Spring MVC controller method:
#RequestMapping(value = "/books", params = "ids", method = RequestMethod.GET)
#ResponseBody
Object getBooksById_params(#RequestParam List<Integer> ids) {
return "ids=" + ids.toString();
}
And you can make a call using next variants:
http://server:port/ctx/books?ids=5,65,42
http://server:port/ctx/books?ids=5&ids=65&ids=42
Also take a look this discussion: https://stackoverflow.com/a/9547490/1881761
Through HTTP path variables
Also you can pass your ids through path variable, see an example below:
#RequestMapping(value = "/books/{ids}", method = RequestMethod.GET)
#ResponseBody
Object getBooksById_pathVariable(#PathVariable List<Integer> ids) {
return "ids=" + ids.toString();
}
And your call will be look like this: http://server:port/ctx/books/5,65,42
Pros of GET HTTP call : It is always used for retrieval of Data.(From this perspective : we should implemented for each and every and retrieval)
Through HTTP parameters
If you need to pass your ids through HTTP parameters, see an axample below:
Here is your Spring MVC controller method:
#RequestMapping(value = "/book", params = "ids", method = RequestMethod.GET)
#ResponseBody
Object getBooksById_params(#RequestParam List<Integer> ids) {
return "ids=" + ids.toString();
}
It works fine but for exceptional case : say URI is above 2048 characters. It means there are many Id's in the list(eg : 1000)
then its throws an exception :
return 414 (Request-URI Too Long)
which is http://www.checkupdown.com/status/E414.html
After some research MY UNDERSTANDING is : The HTTP protocol does not place any a priori limit on the lenght of a URI. Servers MUST be able to handle the URI of any resources they serve, and SHOULD be able to handle URIs of unbounded length if they provide GET-based forms that could generate such URIs. A server SHOULD return 414(Request_URI Too Long) status if a URI is longer than the server can handle.
I have also gone through sites like to get the GET URI length :
http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.2.1
So conclusion, is stick to POST call when there can be variable URI length at runtime for not getting such exception[return 414 (Request-URI Too Long)]
Alternatively, to allow for complex queries you'll need to give the query its own rest language. So to create a query you POST to /library/query then you edit it with things like POST /library/query/12345 with data {id:34} and then you execute the query with GET /library/books?query=12345
Simply you can call list like this:
***/users?id=1&id=2
If you want to read entities from your API you have to use a GET call.
The better way to get them all is to use a query params as filter.
REST DESIGN cannot retrieve more than one entity each time by id.
An example:
GET /library/books/58731 -> returns only one book identified by 58731
GET /library/books?numPages>70 returns all the books with more than 70 pages
I think that If you need to retrieve a lot of books because they have some logic that all matches, try to put it as a queryString.
Another example:
GET /library/books?stored>20150101 returns all the books added to library on 2015
If you give us more information about the collection and the requirements we will answer more directly.
I am trying to write a REST service with Jersey where the GET method should write me a list of objects. The input to the GET method should take the ids of the list.
Say I will pass n numbers of EmployeeId and the service should return me a list of employees.
If it is not possible to have #Consumes in the GET method, will there be any problem in using other methods of http like PUT or POST to retrieve the list of objects?
Using POST and PUT for resource retrieval contradicts the conventions established for the usage of REST over HTTP. Switching to either of them just for the sake of using a #Consumes annotation is simply wrong.
If you need to provide additional scoping information for a collection of resources, place it in the URL. Specifically, you can use query parameters. It's a common pattern to implement pagination this way (by providing some limit and offset parameters). Your use case is very similar.
Let's assume this is the URL of a collection of employee resources
GET http://www.example.com/employees
A single employee could be fetched like this:
GET http://www.example.com/employees/id1
If you want to retrieve several employees, you could use a query string like this:
GET http://www.example.com/employees?ids=id1;id3;id8
The identifiers do not need to be delimited by semicolons, this is just an example of a way you could fetch them. Remember that it's treated as a single parameter! You'll have to split the values.
Here's how you could read such a list from the URL above
#Path("employees")
#GET
public Response getEmployees(#QueryParam("ids") String employees){
List<String> ids = Arrays.asList(employes.split(";"));
// Validate the ids, get data from a database,
// prepare a response and return it
}
Parsing the list can be cumbersome, especially if you want to validate the ids somehow. Jersey has a neat feature you can use here. If a class has a single-string-parameter constructor or a SomeType parse(String) method, it can be injected by the framework by parsing the string passed as a parameter (QueryParam, PathParam, FormParam, etc.)
You can take advantage of it to make your resource class cleaner.
#Path("employees")
#GET
public Response getEmployees(#QueryParam("ids") Employees e){
doFancyStaffWithAValidListOfEmployees(e.asList());
//prepare a response
}
Where Employees is a class with a String constructor or a parse method, containing all the splitting and validation logic, possibly even some database queries.
Here's a nice article on writing such parameter classes
I currently have a .NET method that looks like this - GetUsers(Filter filter) and this is invoked from the client by sending a SOAP request. As you can probably guess, it takes a bunch of filters and returns a list of users that match those filters. The filters aren't too complicated, they're basically just a set of from date, to date, age, sex etc. and the set of filters I have at any point is static.
I was wondering what the RESTful way of doing this was. I'm guessing I'll have a Users resource. Will it be something like GET /Users?fromDate=11-1-2011&toDate=11-2-2011&age=&sex=M ? Is there a way to pass it a Filter without having to convert it into individual attributes?
I'm consuming this service from a mobile client, so I think the overhead of an extra request that actually creates a filter: POST filters is bad UX. Even if we do this, what does POST filters even mean? Is that supposed to create a filter record in the database? How would the server keep track of the filter that was just created if my sequence of requests is as follows?
POST /filters -- returns a filter
{
"from-date" : "11-1-2011",
"to-date" : "11-2-2011",
"age" : "",
"sex" : "M"
}
GET /Users?filter=filter_id
Apologies if the request came off as being a little confused. I am.
Thanks,
Teja
We are doing it just like you had it
GET /Users?fromDate=11-1-2011&toDate=11-2-2011&age=&sex=M
We have 9 querystring values.
I don't see any problem with that
The way I handle it is I do a POST with the body containing the parameters and then I return a redirect to a GET. What the GET URL looks like is completely up to the server. If you want to convert the filter into separate query params you can, or if you want to persist a filter and then add a query param that points to the saved filter that's ok too. The advantage is that you can change your mind at any time and the client doesn't care.
Also, because you are doing a GET you can take advantage of caching which should more than make up for doing the extra retquest.