imguR Package
imguR enables intuitive uploading of plots created in R to the free image hosting service Imgur simply, quickly, and intuitively via the Imgur v3 API. The package is a complete client library for the Imgur API, meaning that one can also delete, favorite, and comment on images, as well as organize them in albums and galleries, among other operations.
By default, all images are loaded to Imgur anonymously. Optionally, using an OAuth2.0 login (see examples below), users can also gain full access to their own Imgur user account.
The Imgur Graphics Device
The two workhorse functions for anonymously uploading images to Imgur are imgur
and imgur_off
, the latter of which wraps dev.off
and completes the image upload.
library('imguR')
i <- imgur('pdf') # first argument to `imgur` is any graphics device function
plot(x=1:10, y=-1:-10, col=1:10, pch=19, main="oh hai dere")
imgur_off(i)
# [1] "http://imgur.com/nsDOm"
To upload images to a user account, first complete an OAuth login (see next section) and then pass the OAuth2.0 token object to imgur
, e.g.:
tkn <- imgur_login()
i <- imgur(token = tkn)
hist(rnorm(100))
imgur_off(i)
OAuth2.0 Support
By default, all operations in imguR are performed anonymously using an API key attached to the imguR package and registered by the package maintainer. To use the package in a non-anonymous fashion (and to obtain higher API rate limits), operations needs to include an token
argument, which must contain an OAuth2.0 token object. Note: Some operations cannot be performed anonymously and must be performed with the token
argument; these operations produce an error if no token
is supplied.
Generating an OAuth2.0 token is easy in an interactive session using imgur_login()
(and completing a user account login in your web browser on a screen that looks like this), the response of which is a Reference Class object that can be passed to all package functions. For example:
# login
tkn <- imgur_login()
# upload a simple plot
i <- imgur(token = tkn)
hist(rnorm(100))
imgur_off(i)
# check account details
account(token = tkn)
account_image_count(token = tkn)
account_album_count(token = tkn)
The OAuth2.0 token is moderately long lived. You can see when it expires by looking at, e.g., tkn$credentials$expiration
. If a token expires, it can be refreshed using the refresh()
method, e.g., tkn$refresh()
.
The ability to refresh the OAuth2.0 token also means that it is possible to use the token non-interactively. First, generate a token and save it locally (with the default cache = TRUE
argument to imgur_login
):
# generate a token interactively
tkn <- imgur_login()
Then, reload (using httr's built-in OAuth caching mechanism) and optionally refresh the token in the non-interactive session before performing any operations:
tkn <- imgur_login()
# tkn$refresh() # refresh token, if expired
i <- imgur(token = tkn)
hist(rnorm(100))
imgur_off(i)
Note: imgur_login
uses OAuth credentials registered to the package maintainer. If you intend to make a very large number of API requests, it may be appropriate to register your own application. You can check user- and package-level rate limits with rate_limit
.
Managing Images
If operations (e.g., upload_image
) are performed with a token
argument, they can subsequently be modified (e.g., update_image
) by passing the relevant identifiers:
i <- imgur(token = tkn)
hist(rnorm(100))
u <- imgur_off(i)
# pass the `imgur_image` object to `update_image`:
update_image(u, title = 'My graph', description = 'A simple graph', token = tkn)
# or, pass just the image id:
update_image(u$id, title = 'My graph', description = 'A simple graph', token = tkn)
If you tried to perform the update_image
operation without passing a token
argument, the operation would fail. Similarly, if an image is uploaded anonymously, it is not possibly to anonymously modify it. Instead, the imgur_image
response object (a simple list) will include a deletehash
element, which is essentially a private key for the image. This can be used to modify the image:
i <- imgur()
hist(rnorm(100))
u <- imgur_off(i)
# pass just the image deletehash:
update_image(u$deletehash, title = 'My graph', description = 'A simple graph')
This procedure can also be used for other API operations, such as modifying albums. Not all operations can be performed anonymously, however.
Requirements and Installation
The current stable version imguR can be installed from CRAN using:
install.packages('imguR')
The development version can be installed directly from GitHub using ghit
:
if(!require('ghit')) {
install.packages('ghit')
}
ghit::install_github('leeper/imguR')