08-other-components.Rmd

# Other components

**What we have seen:** 

- Various states of a package (source -> in-memory)

- Focus on a workflow with frequent test and documentation

- Build time vs. Run time

- How and where store R code

- How and where to store data 


**What we will see see:**

- **"Nice to be aware of"**

- Package metadata: **DESCRIPTION & NAMESPACE** dependencies, licenses

- Testing 

- Documentation

- Maintenance and distribution


**Learning objectives:**

- Getting acquainted with other part of some R package


## Other directories

- `src/`: source and header files for compiled code: need an other book 
    
   * [cpp11 package](https://cpp11.r-lib.org/)  
   * [Rcpp package](https://www.rcpp.org/)  
     
  
- `inst/`: we already see it in the data chapter (`inst/extdata/` [here](https://r-pkgs.org/data.html#sec-data-extdata)). We will add `CITATION` in it

- `tools/`: configure tools and store useful stuff for maintainers 

- `demo/`: legacy phenomenon, we should use a good `README.md` and vignettes ([chapter 17](https://r-pkgs.org/vignettes.html))  

- `exec/`: executable scripts : flagged as executables (?), apparently `inst/` is a preferred location     

- `po/`: translations for messages (both internal and from the package)

## Installed filled

Everything in `inst/` is copied into the top-level directory of the installed package. 

**Warnings**: no subdirectory with a name already in use at the top-level (ie: `inst/data`)

Remember (In dev: `inst/bob` ->  for users: `/bob`): to avoid trouble you can use [`devtools::load_all()`](https://devtools.r-lib.org/reference/load_all.html) or [`fs::path_package()`](https://fs.r-lib.org/reference/path_package.html).


### Package citation:

`citation()` is fetching the `CITATION` file.

- without argument -> how to cite base R

- with a package name (a string: "tidyverse") -> how to cite the package

If you use `usethis::use_citation()` it will, if needed, create a `inst/` and `CITATION` template.

## Congiguration tools : `tools/` 

- official use: Scripts needed at **compile time**, associated with `src/`, they will not be present in the installed package.  

- "unofficial" use : web toolkits, specification for a web API, colour palettes, styles, themes (-> `Rbuildignore`)


## Summary 

- Packages can include a lot of different files!

- Official way and an unofficial one 


## Meeting Videos

### Cohort 1

`r knitr::include_url("https://www.youtube.com/embed/h7BhdVYkM9o")`


### Cohort 2

`r knitr::include_url("https://www.youtube.com/embed/lg9G1R2H-f0")`

`r knitr::include_url("https://www.youtube.com/embed/EjCF7LlvWgI")`


### Cohort 3

There was no meeting that specifically covered this material.


### Cohort 4

`r knitr::include_url("https://www.youtube.com/embed/Dohr28WYaX0")`