I've got an issue when I try to access the request parameters.
As I've read, we have to use request.params.someParam to access the data we're sending via post or get. I'm following these steps, but I obtain an "undefined" response.
The code I use is the following one:
app.post('/hello', function(request, response) {
var query = new Parse.Query(Parse.Installation);
query.equalTo('UserName', request.params.userName); //trying to filter by UserName parameter
response.set('Content-Type', 'text/plain');
});
Does anyone know why do I obtain an undefined response and how to fix it?
Thanks
May I ask how do you specify your request params?
Because I found that when I tried to arrange a background job with request.params in Parse WebGUI, it requires to put a double quote (") for each key. Ex. {"userName":"John"}.
But when the request.params got passed into the background job, the double quote was escaped. Ex. {\"userName\": "John"}. So I can't get the param by request.params.userName
If I send the request via CURL then it all works fine.
Related
This question already has answers here:
Axios get in url works but with second parameter as object it doesn't
(4 answers)
Closed 5 years ago.
I want to send a get request with an object. The object data will be used on the server to update session data. But the object doesn't seem to be sent correctly, because if I try to send it back to print it out, I just get:
" N; "
I can do it with jQuery like this and it works:
$.get('/mysite/public/api/updatecart', { 'product': this.product }, data => {
console.log(data);
});
The object is sent back from server with laravel like this:
public function updateCart(Request $request){
return serialize($request->product);
The same thing doesn't work with axios:
axios.get('/api/updatecart', { 'product': this.product })
.then(response => {
console.log(response.data);
});
I set a default baseURL with axios so the url is different. It reaches the api endpoint correctly and the function returns what was sent in, which was apparently not the object. I only get "N; " as result.
Axios API is a bit different from the jQuery AJAX one. If you have to pass some params along with GET request, you need to use params property of config object (the second param of .get() method):
axios.get('/api/updatecart', {
params: {
product: this.product
}
}).then(...)
You can pass either a plain object or a URLSearchParams object as params value.
Note that here we're talking about params appended to URL (query params), which is explicitly mentioned in the documentation.
If you want to send something within request body with GET requests, params won't work - and neither will data, as it's only taken into account for PUT, POST, DELETE, and PATCH requests. There're several lengthy discussions about this feature, and here's the telling quote:
Unfortunately, this doesn't seem to be an axios problem. The problem
seems to lie on the http client implementation in the browser
javascript engine.
According to the documentation and the spec XMLHttpRequest ignores the
body of the request in case the method is GET. If you perform a
request in Chrome/Electron with XMLHttpRequest and you try to put a
json body in the send method this just gets ignored.
Using fetch which is the modern replacement for XMLHtppRequest also
seems to fail in Chrome/Electron.
Until it's fixed, the only option one has within a browser is to use POST/PUT requests when data just doesn't fit into that query string. Apparently, that option is only available if corresponding API can be modified.
However, the most prominent case of GET-with-body - ElasticSearch _search API - actually does support both GET and POST; the latter seems to be far less known fact than it should be. Here's the related SO discussion.
I've been attempting to inject a custom header for a error response status (and failing).
I have a very simple lambda being used
exports.handler = (event, context, callback) => {
// TODO implement
//callback(null, 'Hello from Lambda');
var error = {
name:"error",
message:"I am a failure",
statusCode: 400
};
error["x-test"] = 'foo';
callback(JSON.stringify(error), null);
};
In the api gateway, I've done the following:
set up CORS to include x-test
responsetemplate = "$input.path('$.errorMessage')"
responseparameter to include:
method.response.header.x-test = integration.response.body.x-test
Also, I have a statusCode mapped using '.*statusCode.*?400.*'
This has turned out empty.
so I decided to take a step back and see what happens if I do:
method.response.header.x-test = integration.response.body
I found that I get the stringified response of errorMessage.
{"x-test":"{\"errorMessage\":\"{\\\"name\\\":\\\"error\\\",\\\"message\\\":\\\"I am a failure\\\",\\\"statusCode\\\":400,\\\"x-test\\\":\\\"foo\\\"}\"}"}
So I decided to change the responsetemplate to force it to json by doing the following:
responsetemplate = "$util.parseJson($input.path('$.errorMessage'))"
and I still get the stringified response:
{"x-test":"{\"errorMessage\":\"{\\\"name\\\":\\\"error\\\",\\\"message\\\":\\\"I am a failure\\\",\\\"statusCode\\\":400,\\\"x-test\\\":\\\"foo\\\"}\"}"}
My guess is that it doesn't transform as expected, but only for the final output.
So how would you take a value and shove it into a header?
Thanks,
Kelly
I think this is more of a design choice regarding the limitation imposed by both Lambda and APIGateway. I will try my best to walk through my thoughts.
First of all, in Lambda, callback(error, result) function can either take an error string as first argument, or an object as result response. If you want to pass along a simple error message, you could definitely just do that. However, in your case, as you tried to pass along an entire error object, choosing the second option is clearly a better solution (in contrast to stringifying an object and parse it into object again). As a result, the final line of your Lambda function should be:
callback(null, error);
Yes, in this case, if you test your function in Lambda, the output result will no longer be red and flag it as an error, but this won't matter as you can format your headers and response in APIGateway.
Now you need to set things up in APIGateway, in which you need to make use of the object passed by Lambda.
It's actually rather easy to use method execution interface to configure headers.
In Method Response, you need to add the headers you want to include in the response for a specific status code, which in your case is x-test. (If you want the API to return different status codes, you can also configure that in this panel.)
Then go to Integration Response, under the same status code, you will see the added header available. According to this documentation from AWS, you can use integration.response.body.JSONPath_EXPRESSION to assign the header value (this is another reason that you should return object rather than string in Lambda, as there is no formal API to parse object from string at this stage). This time, as your Lambda is passing an object, the value of x-test header is:
integration.response.body['x-test']
Now your API should have the proper header included.
NOTE: In order to set up different status code in APIGateway, you should leave some distinguishable data fields (your statusCode: 400 should work perfectly) in you response body, so you can use RegEx to match those fields to a specific status code.
So... above doesn't work with success message. I found this blog though talking about error handling design pattern. Apparently what they suggest is only mapping status code when there is an error, in which case no body should be passed (only the errorMessage), as browser won't care about response body for a status code other than 200 anyway.
I guess after all, it is impossible to customize both status code and header at the same time with Lambda passing an object to APIGateway?
This is due to the fact that you are stringifying the error object coming from your Lambda function. API Gateway attempts to resolve the JSON-Path expression and can't evaluate "x-test" in a string. If you return an object instead of a string, this should work.
You may want to consider using proxy integrations which allow you to control the headers and status directly from your Lambda function.
Update: I've written a blog post on this topic with sample code # https://rpgreen.wordpress.com/2017/01/25/how-to-send-response-headers-for-aws-lambda-function-exceptions-in-api-gateway/
How can I customize $http in angularjs such that it will accept strings as its response in a $http.post call? Right now, when I do a $http.post call, my response is in string but angularjs by default uses JSON therefore I get an error. Right now I have something along the lines of
function getResponseURL(response) {
//this will convert the response to string
return response;
}
$http.defaults.transformResponse = [];
$http.defaults.transformResponse.unshift(getResponseURL);
However if I use the code above, any $http.post calls after that call uses string. I want it to use the original default JSON format. How can I go about into just temporarily changing the response to string for this one call but the rest stay as JSON type as a response?
Why not only register that transform for ONLY that request?
Angular js $http docs
If you wish
override the request/response transformations only for a single
request then provide transformRequest and/or transformResponse
properties on the configuration object passed into $http.
I have an url with query args:
var url = 'http://example.com/ajax.php?action=update_count&product=1234'
So, all query args I need to send for ajax request is already in URL, I tried this:
$.post( url, '', callback, 'json');
But, it won't send POST data.
So, I want to ask shall I do ajax/post request without data object/string, as query args are already in url.
Thanks.
If you put a parameter in the URL, it's treated like a GET parameter, not a POST parameter. You need to use whatever server-side mechanism is normally used for getting URL parameters. For instance, in PHP it would be $_GET['action'] and$_GET['product']`.
If you want to be able to send a parameter in either GET or POST, you can use PHP's $_REQUEST variable. It merges both sets of parameters.
When I use HTTPService.send(paramter) as a POST request, the web server does not appear to see variable "parameter" if it is a string. The server sees the parameter if it's an Object, but I'm looking to use something like httpservice.send(JSON.encode(object)); Is this possible?
Why not use the actual request objects.
in your service define request objects and post them or send them as get if you please.
Sample code here: http://pastebin.com/ft7QW2vg
Then just call .send on the service.
on the server you can simlpy process if with request.form (Asp)
Failing which why not append it to the url with a binding expression. (you would need to encode it since you would be more or less faking a url or a get behaviour).