In KarlMert/URL_To_File: URL to File

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

Create a file directly from a URL

This function was created to streamline the process of downloading files from URLs. The usual approach is to download a file onto OS storage, then drag and drop or copy and paste. This can create duplicate files, incomplete or incorrect transfer; this is a fragile, low fidelity processs. Another benefit, in terms of reproducability is that the URL where the data was aquired can be a part of the markdown file. This makes the URL clear and accessable when generating citations and easily updated when needed. NOTE: you may need to change the URL in this vigenette, since they are frequently updated.

The file below is an R script from a github repository. Function could be useful for downloading only data or a file from a github repository; rather than the whole directory and contents.

Example: Find data on Github

In this example, we are going to download an R script from Github. Circa 2018, you can find the raw address by navigating directly to a file within a repository.

knitr::include_graphics("findraw.png")

After clicking on the "Raw" button circled above, the browser will display the contents of the file. Copy the URL and paste in quotes in the url2file function, as the first arguement.

knitr::include_graphics("raw.png")

The 'raw' section of the URL is highlighted above. In the Github environment, 'raw' refers to pages that display script or data files - the kind we can use in R. If the page is not at a 'raw' address, then a copy of the webpage will be downloaded.

Paste URL into `url2file` function

In the first example below, the URL is pasted within quotes, and the dirID (directory identity or file name) is left blank. In this case, a new file will be created with the default name "Downloaded_files". You can refer to the url2file.R in the package files to see the exact script of this function.

url2file("https://raw.githubusercontent.com/opetchey/RREEBES/Beninca_development/Beninca_etal_2008_Nature/report/functions/indirect_method_functions.R", dirID = )

The default filename can be changed to anything you wish by specifying a different name.

url2file("https://raw.githubusercontent.com/opetchey/RREEBES/Beninca_development/Beninca_etal_2008_Nature/report/functions/indirect_method_functions.R", dirID = "Rscripts")