How to access air quality API through R?

Question

Trying to access AirQuality API, very new to this and do not see simple R tutorials.

Got my username and password.

And I am interested to get LA data as a sample

api.airvisual.com/v2/city?city=Los Angeles&state=California&country=USA&key={{KEY}}

My credentials

username <- "My new free api key" (that is how they give it)

password <- "KEY"

Then I try to use some code from tutorials

library(httr)
library(jsonlite)

url <- "api.airvisual.com/v2/city?city=Los Angeles&state=California&country=USA&key={{KEY}}"

endpoint <- "city"

some_data <- GET(url, endpoint)

It gives me an error

Error in if (is_http) { : argument is of length zero

Their parameters are

Parameters

city: city's English name, can be found using the respective listing endpoint.

state: state's English name, can be found using the respective listing endpoint.

country: country's English name, can be found using the respective listing endpoint.

I am sure it is something super simple, but I never did it before, so I stumbled. Please advise.

UPD.

When I use

url <- "api.airvisual.com/v2/city?city=Los%20Angeles&state=California&country=USA&key={{KEY}}"

with %20 instead of space, it gives me an error

Error in UseMethod("as.request") : no applicable method for 'as.request' applied to an object of class "character"

the space in the URL might give you problems; it may need to be encoded into `%20` - [reference](https://stackoverflow.com/q/1634271/5977215) — SymbolixAU, Oct 23 '19 at 04:54
@SymbolixAU, interesting. I am copying from the tutorial. There is a space there. — Anakin Skywalker, Oct 23 '19 at 05:45
It's not in the example request they give `curl --location --request GET "api.airvisual.com/v2/city?city=Los%20Angeles&state=California&country=USA&key={{YOUR_API_KEY}}"` - it's been encoded to `%20` — SymbolixAU, Oct 23 '19 at 05:57
@SymbolixAU, ok I see, but on the left side they do not give it. But still does not work, I tried with a new link. Please see the error. — Anakin Skywalker, Oct 23 '19 at 05:59
@SymbolixAU, Error in if (is_http) { : argument is of length zero — Anakin Skywalker, Oct 23 '19 at 06:23

makeshift-programmer · Accepted Answer · 2019-10-23T07:52:21.767

2

I don't think you need to specify endpoint. You can directly use GET as follows:

require(httr)
response = GET("https://api.airvisual.com/v2/city?city=Los%20Angeles&state=California&country=USA&key={{my_private_key}}")

If you further need to access data from the response, the code would be:

data = content(response)

data is a list which looks like:

$status
[1] "success"

$data
$data$city
[1] "Los Angeles"

$data$state
[1] "California"

$data$country
[1] "USA"

$data$location
$data$location$type
[1] "Point"

$data$location$coordinates
$data$location$coordinates[[1]]
[1] -118.2417

$data$location$coordinates[[2]]
[1] 34.0669



$data$current
$data$current$weather
$data$current$weather$ts
[1] "2019-10-23T07:00:00.000Z"

$data$current$weather$tp
[1] 20

$data$current$weather$pr
[1] 1014

$data$current$weather$hu
[1] 52

$data$current$weather$ws
[1] 0.78

$data$current$weather$wd
[1] 345

$data$current$weather$ic
[1] "01n"


$data$current$pollution
$data$current$pollution$ts
[1] "2019-10-23T07:00:00.000Z"

$data$current$pollution$aqius
[1] 37

$data$current$pollution$mainus
[1] "p1"

$data$current$pollution$aqicn
[1] 41

$data$current$pollution$maincn
[1] "p1"

Let me know if this works.

P.S. I even tried for Los Angeles using %20 instead of the space and it works.

edited Oct 23 '19 at 07:52

answered Oct 23 '19 at 07:34

makeshift-programmer

489
3
8

Thanks! Can you please share the FULL code from your IDE? I am still struggling. Maybe I am missing something simple. Please update your answer a bit. With password etc. – Anakin Skywalker Oct 23 '19 at 07:44
1

@Oleksiy I have added the full code from my console and the output too. If you tell me what error you are getting, I will be able to debug. – makeshift-programmer Oct 23 '19 at 07:53
library(httr) response <- GET("api.airvisual.com/v2/city?city=Mumbai&state=Maharashtra&country=India&key={MYKEY}") gives me an error Error in if (is_http) { : argument is of length zero. – Anakin Skywalker Oct 23 '19 at 08:04
1

Add 'https://' in the beginning of the URL. Just to be safe, encode your key as ```URLencode(MYKEY)``` where MYKEY is a string object containing your key. – makeshift-programmer Oct 23 '19 at 08:06
Ok, did some progress – Anakin Skywalker Oct 23 '19 at 08:11
$status [1] "fail" $data $data$message [1] "incorrect_api_key" – Anakin Skywalker Oct 23 '19 at 08:11
1

Are you sure the api key is correct? If you are 100% sure, then remove the URLencode part. – makeshift-programmer Oct 23 '19 at 08:12
Well, I just copy-pasting from the dashboard. – Anakin Skywalker Oct 23 '19 at 08:14
Can you please give the specific code with ``URLencode``. Maybe the error is there. – Anakin Skywalker Oct 23 '19 at 08:51
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/201307/discussion-between-makeshift-programmer-and-oleksiy). – makeshift-programmer Oct 23 '19 at 08:52

score 1 · Answer 2 · answered Oct 23 '19 at 07:40

1

You have to provide the scheme as part of the URL:

library(httr)
GET("https://api.airvisual.com/....")
     ^^^^^^^^

answered Oct 23 '19 at 07:40

Hong Ooi

56,353
13
134
187

How to access air quality API through R?

2 Answers2