I have some base64 encoded JSON, for example: eyJiYXIiOiJibGFuIn0= (this is just {"bar": "blan"}.
I'm using axios to make an http request, although I'm willing to use another library or http if need be. I want to be able to transmit the data as a JSON string with as few steps / as efficiently as possible. Currently I do:
axios({
url,
method: "POST",
data: new Buffer(data, "base64").toString(),
headers: {
"Content-type": "application/json",
},
})
However, this reads the entire string into memory from the buffer, so I'm wondering if there is a better way. If I don't use toString it doesn't work, and the JSON parser on the server responds with: Unexpected token '.
Is there a better way to transmit data from a base64-encoded string?
Related
I am sending a post request from my flutter to a localhost api. However, the body on the server side is always empty/null. Whereas, if I send the exact same request on postman everything works fine.
String json = jsonEncode(toCheck);
Map<String,String> headers = {
"Accept": "application/json",
"content-type": "application/json",
};
var response = await http.post(
Uri.parse(userPath + 'validateUser/'),
headers: headers,
body: "{\"email\":\"david#hotmail.com\",\"username\":\"\",\"mobile_phone_number\":\"\",\"password\":\"david\"}");
print(response.statusCode);
if(response.statusCode == HttpStatus.ok){
return response.body as bool;
}
print(response.body.toString());
return false;
The status code is always 500 with the following error:
{"Message":"An error has occurred.","ExceptionMessage":"The value cannot be null"...
This error happens because the parameter "json" is null:
[HttpPost]
[Route("validateUser/", Name = "validadeUser")]
public async Task<IHttpActionResult> ValidateUser([FromBody] string json)
{
//get the username and password to validate the user
UserClient client = JsonConvert.DeserializeObject<UserClient>(json); //error happens here because the string json is null
//...
}
However, when making the same exact request on postman, everything is okay:
The host on the android emulator app is the following:
https://10.0.2.2:44304/api/user/validateUser/
PS: looks like a duplicate of Flutter POST request body is empty on server side and Flutter Dart HTTP POST request body is empty on server side but none of those solutions have worked for me, therefore I posting a new question.
It took me a while to spot the error... but in the end, I did!
Your API takes a String argument from the request body:
ValidateUser([FromBody] string json)
That may seem alright at first, since indeed, you are sending a json String as your request body. But the thing is that since you're also using these headers:
{
"Accept": "application/json",
"content-type": "application/json",
}
This bit: "content-type": "application/json" will translate your correctly formatted json String into an actual json Object! So when it reaches your API, it will no longer be a String, and so your API won't be able to receive it properly.
The solution would be to either remove the "content-type": "application/json" from your headers and keep the request body and the API function as they are, or to change the API to:
ValidateUser([FromBody] object json)
The latter is probably the most convenient, since you were going to parse it from json String to json Object anyway! 🙂
(With this API function, you COULD also remove your "content-type": "application/json" bit from the headers, and then send the request body like this:
body: jsonDecode("{\"email\":\"david#hotmail.com\",\"username\":\"\",\"mobile_phone_number\":\"\",\"password\":\"david\"}"),
Or just not jsonEncode it in the first place... Just send it as an object. This will have the same effect as sending it as a json String with "content-type": "application/json" in the header.)
Btw, as a general rule, make sure you add lots of print and log statements in your code as you develop it! It will help you spot anything that didn't go quite as you had expected, along the way. 😉 (That's how I spotted this.)
Before sending the request to the server please encode your object to complete the body property of the request. Try this:
body: json.encode({\"email\":\"david#hotmail.com\",\"username\":\"\",\"mobile_phone_number\":\"\",\"password\":\"david\"})
Cheers.
let jsonString = JSON.stringify(json);
console.log(jsonString); //prints {"5667787":"currentTaxless":99.82,"current":123.78}}
GM.xmlHttpRequest({
method: "POST",
url: "https://exampleau.tld",
data: jsonString,
headers: {
"Content-Type": "application/x-www-form-urlencoded"
},
onload: function(response) {
//stuff
}
});
Hi,
I am starting to feel myself stupid. I haven't found any way to feed into data regular object/array or json, no matter what I did (changed headers, added dataType, feed that json variable) - the data was not posted. Only this solution posts data. In the Greasemonkey documentation there is nothing about feeding plain json.
The problem is, that on backend, when I receive such a data - it is:
an array with single key and no value
the key is html_entity_encode(d) string
where dots in float numbers are replaced with underscores. This is what I am getting:
{"5667787":{"currentTaxless":99_82,"current":123_78}}
Qusetion: What am I doing wrong or how to post without a hassle or receive normally formatted posted data without a hassle using Greasemonkey???
Versions: Greasemonkey v4.11
Firefox v81
Nevermind.
The solution is not to
data: jsonString,,
but rather explicitly put json string under some key as value like this
data: 'data=' + jsonString,
I am trying to send data to a server (local rest API) from react using post request, if i send an object like this:
{key:"value"}
then i get this at the server:
{ '{"key":"value"}': '' }
It's converting the whole object into key-value pair.
How can i solve this issue?
axios.post('http://localhost:5000/animals', JSON.stringify(data))
.then((response)=>{
console.log(response);
});
If I don't stringify, then I get an empty object at the server, but if I do stringify, then I get this sort of object as mentioned above. Is there any way to convert it back to a normal object?
It looks like the server expects to get data in application/x-www-form-urlencoded encoding, not application/json.
Why?
application/x-www-form-urlencoded encoded data looks like
key1=value1&key2=value2&....
But values are optional, so
key1&key2=value2
works too.
You are sending {"key":"value"} which to the server looks like a key without a value. Since it looks like you have control over the server, change the server implementation to parse the request body as JSON instead. How to do that depends on the framework you are using on the server.
If you are using express.js, use bodyParser.json(). Alternatively send the data application/x-www-form-urlencoded encoded, not as JSON, as suggested by Chinedu.
Performing a POST request with axios
axios.post('/user', {
firstName: 'Fred',
lastName: 'Flintstone'
})
.then(function (response) {
console.log(response);
})
.catch(function (error) {
console.log(error);
});
Can you try constructing the data you want to send as the above exam, send to your api and see if the dummy data comes. No json parse or stringfy needed.
Are you using body-parser middleware in your nodejs express app?
Can someone explain in an easy way how to make jQuery send actual JSON instead of a query string?
$.ajax({
url : url,
dataType : 'json', // I was pretty sure this would do the trick
data : data,
type : 'POST',
complete : callback // etc
});
This will in fact convert your carefully prepared JSON to a query string. One of the annoying things is that any array: [] in your object will be converted to array[]: [], probably because of limitations of the query sting.
You need to use JSON.stringify to first serialize your object to JSON, and then specify the contentType so your server understands it's JSON. This should do the trick:
$.ajax({
url: url,
type: "POST",
data: JSON.stringify(data),
contentType: "application/json",
complete: callback
});
Note that the JSON object is natively available in browsers that support JavaScript 1.7 / ECMAScript 5 or later. If you need legacy support you can use json2.
No, the dataType option is for parsing the received data.
To post JSON, you will need to stringify it yourself via JSON.stringify and set the processData option to false.
$.ajax({
url: url,
type: "POST",
data: JSON.stringify(data),
processData: false,
contentType: "application/json; charset=UTF-8",
complete: callback
});
Note that not all browsers support the JSON object, and although jQuery has .parseJSON, it has no stringifier included; you'll need another polyfill library.
While I know many architectures like ASP.NET MVC have built-in functionality to handle JSON.stringify as the contentType my situation is a little different so maybe this may help someone in the future. I know it would have saved me hours!
Since my http requests are being handled by a CGI API from IBM (AS400 environment) on a different subdomain these requests are cross origin, hence the jsonp. I actually send my ajax via javascript object(s). Here is an example of my ajax POST:
var data = {USER : localProfile,
INSTANCE : "HTHACKNEY",
PAGE : $('select[name="PAGE"]').val(),
TITLE : $("input[name='TITLE']").val(),
HTML : html,
STARTDATE : $("input[name='STARTDATE']").val(),
ENDDATE : $("input[name='ENDDATE']").val(),
ARCHIVE : $("input[name='ARCHIVE']").val(),
ACTIVE : $("input[name='ACTIVE']").val(),
URGENT : $("input[name='URGENT']").val(),
AUTHLST : authStr};
//console.log(data);
$.ajax({
type: "POST",
url: "http://www.domian.com/webservicepgm?callback=?",
data: data,
dataType:'jsonp'
}).
done(function(data){
//handle data.WHATEVER
});
If you are sending this back to asp.net and need the data in request.form[] then you'll need to set the content type to "application/x-www-form-urlencoded; charset=utf-8"
Original post here
Secondly get rid of the Datatype, if your not expecting a return the POST will wait for about 4 minutes before failing. See here
I'm new to MVC3 framework (and .NET overall; Java veteran), so bear with me, but here goes:
Input submitted to a Controller as JSON doesn't seem to be subject to the HttpRequestValidation -- Does that sound right?
I realize if you're receiving data input via JSON you're possibly already doing more work with it, but the Controller Action doesn't seem to necessarily know whether it has JSON data at that point; input values are mapped to parameters just as they would be if they were standard POST params.
Example - I'm asynchronously submitting JSON data to my Controller like the following:
var data = { "title": $titleField.val(), "content": $textArea.val(),
"location": $location.val()
};
$.ajax(submitUrl,
{
type: "POST",
contentType: "application/json; charset=utf-8",
complete: function (data) {
//blah blah
},
dataType: 'json',
data: JSON.stringify(data)
});
}
I then receive the input in my Action:
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult New(string title = "", string content = "", string location = "")
{
//yada yada
}
Doing this, params are mapped and the user can easily send tags, etc. I'm not turning ValidateInput off, and if I submit with a standard POST and remove the Stringify, it throws the error as expected. Any good reason why JSONified data would skip validation?
Edit - More specific question: If JSONified data will pass HttpRequestValidation, how can we protect against the event where someone would intentionally mock a request to send JSON data instead of post params? I haven't found a way to force the Action method to differentiate between params passed as JSON vs. those passed non-encoded.
Got an answer for my question over on asp.net - See 2nd response.
Solution involves replacing the default ModelBinder.
Any good reason why JSONified data would skip validation?
JSON is encoded => so it ensures that what transits over the wire is safe. When you use JSON.stringify all dangerous characters are encoded.