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HTTP? httr! (1)

Downloading a file from the Internet means sending a GET request and receiving the file you asked for. Internally, all the previously discussed functions use a GET request to download files.

httr provides a convenient function, GET() to execute this GET request. The result is a response object, that provides easy access to the status code, content-type and, of course, the actual content.

You can extract the content from the request using the content() function. At the time of writing, there are three ways to retrieve this content: as a raw object, as a character vector, or an R object, such as a list. If you don't tell content() how to retrieve the content through the as argument, it'll try its best to figure out which type is most appropriate based on the content-type.

Deze oefening maakt deel uit van de cursus

Intermediate Importing Data in R

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Oefeninstructies

  • Load the httr package. It's already installed on DataCamp's servers.
  • Use GET() to get the URL stored in url. Store the result of this GET() call as resp.
  • Print the resp object. What information does it contain?
  • Get the content of resp using content() and set the as argument to "raw". Assign the resulting vector to raw_content.
  • Print the first values in raw_content with head().

Praktische interactieve oefening

Probeer deze oefening eens door deze voorbeeldcode in te vullen.

# Load the httr package


# Get the url, save response to resp
url <- "http://www.example.com/"


# Print resp


# Get the raw content of resp: raw_content


# Print the head of raw_content
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