I am writing an analysis report with rmarkdown and would like to have a "document versions" section in which I would indicate the different versions of the document and the changes made.
Instead of writing it down manually, I was thinking about using git history and inserting it automatically in the markdown document (formatting it in a table).
How can I do that? Is it possible?
Install git2r, https://github.com/ropensci/git2r then you can do stuff like:
> r = repository(".")
> cs = commits(r)
> cs[[1]]
[02cf9a0] 2017-02-02: uses Rcpp attributes instead of inline
So now I have a list of all the commits on this repo. You can get the info out of each commit and format as per your desire into your document.
> summary(cs[[1]])
Commit: 02cf9a0ff92d3f925b68853374640596530c90b5
Author: barryrowlingson <b.rowlingson@gmail.com>
When: 2017-02-02 23:03:17
uses Rcpp attributes instead of inline
11 files changed, 308 insertions, 151 deletions
DESCRIPTION | - 0 + 2 in 2 hunks
NAMESPACE | - 0 + 2 in 1 hunk
R/RcppExports.R | - 0 + 23 in 1 hunk
R/auxfunctions.R | - 1 + 1 in 1 hunk
R/skewt.r | - 0 + 3 in 1 hunk
R/update_params.R | - 1 + 1 in 1 hunk
R/update_params_cpp.R | -149 + 4 in 2 hunks
src/.gitignore | - 0 + 3 in 1 hunk
src/RcppExports.cpp | - 0 + 76 in 1 hunk
src/hello_world.cpp | - 0 + 13 in 1 hunk
src/update_params.cpp | - 0 +180 in 1 hunk
So if you just want the time and the commit message then you can grab it out of the object.
> cs[[3]]@message
[1] "fix imports etc\n"
> cs[[3]]@committer@when
2017-01-20 23:26:20
I don't know if there's proper accessor functions for these rather than using @-notation to get slots. Need to read the docs a bit more...
You can make a data frame from your commits this way:
> do.call(rbind,lapply(cs,function(cs){as(cs,"data.frame")}))
which converts the dates to POSIXct objects, which is nice. Creating a markdown table from the data frame should be trivial!