JSON API Callback

Question

I have a question as to how to filter results from a API, and I wonder if anyone has had this problem before.

Let’s say we have to access a API which is on a server other than ours and which returns an answer in JSON with a structure similar to the following

[
{
"nome": "Joshua",
"sex": "M"
},
{
"name": "Marie",
"sex": "F"
},
{
"name": "Frank",
"sex": "M"
}
]

Of course, this is just one example, because the answer could be millions of results. The callback to initiate the communication JSONP is ?callback=...?.

What I’d like to know is if there’s a way to filter these results, let’s imagine that we just want to return people from sexo masculine (M), without having to do a customer-side filtering. Remember that to make this call, can only be done through Javascript without resorting to another type of language.

My first idea would be to make a call using jQuery this way:

$.ajax({
type: 'GET',
url: "https://url-to-api?callback=?",
async: false,
jsonpCallback: 'jsonCallback',
contentType: "application/json",
data:{'sex':'M'},
dataType: 'jsonp',
success: function(json) {
console.dir(json);
},
error: function(e) {
console.log(e.message);
}

Does anyone know a way to filter when making the request?
Thanks for your time.

Answer 1

If the JSON site does not allow filtering parameters then you have to do it on the client side.

Take a look at the API of this site.

Filtering on the client side you can use the .filter(). Check if the JSON that the site has passed is processed as JSON or already as array, I will include this check in the example below:

var parametroFiltragem = 'M';
$.ajax({
    type: 'GET',
    url: "https://url-to-api?callback=?",
    jsonpCallback: 'jsonCallback',
    contentType: "application/json",
    dataType: 'jsonp',
    success: function (json) {
        if (typeof json == 'string') json = JSON.parse(json);
        var filtrados = json.filter(function(obj){
            return obj.sex == parametroFiltragem;
        });
        // fazer algo somente com os "filtrados"
    },
    error: function (e) {
        console.log(e.message);
    }
});

Answer 2

I think the code below might be what you’re looking for:

$.ajax({
    type: 'GET',
    url: "https://url-to-api/pagina",
    data: {
        sex: "M"
    },
    dataType: "jsonp",
    crossDomain: true,
    cache: false,
    success: function (json) {
        alert(json);
    },
    error: function (e) {
        alert(e.statusText +": "+ e.status);
    }
});

In your comment you said that the request will be made for another domain, for this we activated crossDomain, feature that allows you to perform ajax request for other domains.

In this case by default I disabled the cache, however, it is up to you to use or not.

In the date parameter I only removed the quotation marks of the word "sex".

Note: "your sex filter will only work if the API is on the other side has implemented this parameter as filter, otherwise you will have to return all data and create the client-side filter."