It is common to pass a parameter with multiple values as a query string on a GET:
http://server/status?stat=a&stat=b
How does one create this type of query string using the axios library in JS? Creating an object where the parameter name is the key and the value is the array of multiple values creates a query string:
http://server/status?stat[]=a&stat[]=b
which is an incorrect format from what the server expects. Can this be done in axios?
If the server expects a get with multiple instances of a given name (without the [] array marker appended) that can be obtained using the URLSearchParams API.:
var searchParams = new URLSearchParams(); searchParams.append('stat', 'a') searchParams.append('stat', 'b') axios.get('http://server/status', {params: searchParams});
Would yield a request:
http://server/status?stat=a&stat=b
As noted in another answer it does not work in IE, but the polyfill url-search-params is available.
It is common to pass a parameter with multiple values as a query string on a GET
This is by no means a standard. Different languages, frameworks implement different solutions. See this question on the Authoritative position of duplicate HTTP GET query keys.
Can this be done in axios?
From the Axios documentation:
In node.js, you can use the querystring module as follows:
var querystring = require('querystring'); axios.post('http://something.com/', querystring.stringify({ foo: 'bar'});You can also use the qs library.
The qs library has support for arrays.
An alternative would be to use Connect.
Update
The QS library supports arrays, but only if the parameter is suffixed with []:
var paramsString = "q=URLUtils.searchParams&topic[]=api&topic[]=bar"
Alternatively, the URLSearchParams API offers a getAll() method:
var paramsString = "q=URLUtils.searchParams&topic=api" var searchParams = new URLSearchParams(paramsString); searchParams.getAll("topic"); // ["api"]
This doesn't work in IE, but the polyfill url-search-params is available.
?key=stat&value=1,2,3 which would result in stat = [1,2,3]?