@JennyBryan posted her [slides from the 2015 R Summit](https:\/\/github.com\/jennybc\/2015-06-28_r-summit-talk) and they are a must-read for instructors and even general stats\/R-folk. She’s one of the foremost experts in R+GitHub and her personal and class workflows provide solid patterns worth emulation.<\/p>\n
One thing she has mentioned a few times—and included in her R Summit talk—is the idea that you can lean on GitHub when official examples of a function are “kind of thin”. She uses a search for `vapply` as an example, showing how to [search for uses of `vapply` in CRAN](https:\/\/github.com\/search?utf8=%E2%9C%93&q=vapply+extension%3AR+user%3Acran) (there’s a [read-only CRAN mirror on GitHub](http:\/\/www.r-pkg.org\/)) and [in GitHub R code in general](https:\/\/github.com\/search?utf8=%E2%9C%93&q=vapply+extension%3AR).<\/p>\n
I remember throwing together a small function to kick up a browser from R for those URLs (in a response to one of her tweets), but realized this morning (after reading her slides last night) that it’s possible to not leave RStudio to get these GitHub search results (or, at least the first page of results). So, I threw together [this gist](https:\/\/gist.github.com\/hrbrmstr\/32e9c140129d7d51db52) which, when sourced, provides a `ghelp` function. This is the code:<\/p>\n
ghelp <- function(topic, in_cran=TRUE) {\r\n \r\n require(htmltools) # for getting HTML to the viewer\r\n require(rvest) # for scraping & munging HTML\r\n\r\n # github search URL base\r\n base_ext_url <- \"https:\/\/github.com\/search?utf8=%%E2%%9C%%93&q=%s+extension%%3AR\"\r\n ext_url <- sprintf(base_ext_url, topic)\r\n\r\n # if searching with user:cran (the default) add that to the URL \r\n if (in_cran) ext_url <- paste(ext_url, \"+user%3Acran\", sep=\"\", collapse=\"\")\r\n \r\n # at the time of writing, \"rvest\" and \"xml2\" are undergoing some changes, so\r\n # accommodate those of us who are on the bleeding edge of the hadleyverse\r\n # either way, we are just extracting out the results for viewing in \r\n # the viewer pane (it works in plain ol' R, too)\r\n if (packageVersion(\"rvest\") < \"0.2.0.9000\") { \r\n require(XML)\r\n pg <- html(ext_url)\r\n res_div <- paste(capture.output(html_node(pg, \"div#code_search_results\")), collapse=\"\")\r\n } else {\r\n require(xml2)\r\n pg <- read_html(ext_url)\r\n res_div <- as.character(html_nodes(pg, \"div#code_search_results\"))\r\n }\r\n\r\n # clean up the HTML a bit \r\n res_div <- gsub('How are these search results\\\\? Tell us!<\/span>', '', res_div)\r\n # include a link to the results at the top of the viewer\r\n res_div <- gsub('href=\"\/', 'href=\"http:\/\/github.com\/', res_div)\r\n # build the viewer page, getting CSS from github-proper and hiding some cruft\r\n for_view <- sprintf('