Build Rules

rRule()

Executes an R script using Rscript. The rule is triggered when any dependency or the script itself changes.

rRule(target, script, depends = NULL, params = list(), task = "all")

Parameters:

• target - Name of the output file to be created
• script - Name of the R script to execute
• depends - Vector of file names that the script depends on, or NULL
• params - List of R values that become available within the script in a params variable
• task - Character vector of parent task names

Example:

rRule(target = "output.rds", 
      script = "process.R", 
      depends = "input.csv")

markdownRule()

Renders a document from R Markdown using rmarkdown::render().

markdownRule(target, script, depends = NULL, format = "all",
             params = list(), task = "all")

Parameters:

• target - Name of the output file to be created
• script - Name of the R Markdown file to render
• depends - Vector of file names that the markdown script depends on, or NULL
• format - Output format specification (see below)
• params - List of R values available within the script in a params variable
• task - Character vector of parent task names

Format Options:

• "all" - All formats defined in the Rmd file
• "html_document" - HTML web page
• "pdf_document" - PDF document
• "word_document" - Microsoft Word
• "odt_document" - OpenDocument Text
• "rtf_document" - Rich Text Format
• "md_document" - Markdown
• Vector of format names for multiple formats

Example:

markdownRule(target = "report.pdf",
             script = "report.Rmd",
             depends = "data.rds",
             format = "pdf_document")

knitrRule()

Executes knitr to create a text file using knitr::knit(). This is useful for processing Sweave-style documents (.Rnw files).

knitrRule(target, script, depends = NULL, params = list(), task = "all")

Parameters:

• target - Name of the output file to be created
• script - Name of the Rnw file to be rendered
• depends - Vector of file names that the knitr script depends on, or NULL
• params - List of R values available within the script in a params variable
• task - Character vector of parent task names

Example:

knitrRule(target = "report.tex",
          script = "report.Rnw",
          depends = c("data1.csv", "data2.csv"))

copyRule()

Copies a file from one location to another. The rule executes $(CP) depends[1] target.

copyRule(target, depends, task = "all")

Parameters:

• target - Target file name to copy the file to
• depends - Name of the file to copy from (only the first element is used)
• task - Character vector of parent task names

Example:

copyRule(target = "backup/data.csv",
         depends = "data.csv")

depRule()

Defines a dependency between targets without providing any execution script. This is useful when you want to specify that a target depends on another target but don’t need to execute any command to build it.

depRule(target, depends = NULL, task = "all")

Parameters:

• target - Target file name that depends on depends
• depends - Character vector of prerequisite file names
• task - Character vector of parent task names

Example:

# Ensure all preprocessing is done before starting the analysis
depRule(target = "analysis-ready",
        depends = c("data1.rds", "data2.rds", "data3.rds"))

subdirRule()

Runs the make process in a subdirectory. The subdirectory is assumed to contain its own Makefile. This rule executes make <targetTask> in the specified subdirectory.

subdirRule(target, depends = NULL, task = "all", targetTask = "all")

Parameters:

• target - Name of the subdirectory
• depends - Must be NULL
• task - Character vector of parent task names
• targetTask - What task to execute in the subdirectory (default: “all”)

Example:

subdirRule(target = "subproject",
           targetTask = "all")

offlineRule()

Forces manual action within the build process. Shows a custom error message instructing the user to perform a task manually. This is useful when transformation requires manual intervention.

offlineRule(target, message, depends = NULL, task = "all")

Parameters:

• target - Name of the file to be created manually
• message - Custom message to display to the user
• depends - Vector of prerequisite file names, or NULL
• task - Character vector of parent task names

Example:

offlineRule(target = "cleaned_data.csv",
            message = "Please manually clean data.csv and save as cleaned_data.csv",
            depends = "data.csv")

Using inShell()

The inShell() function converts R expressions to shell commands:

inShell({ result <- 1 + 1; saveRDS(result, "result.rds") })
#> [1] "$(R) - <<'EOFrmake'"                 "{"                                  
#> [3] "    result <- 1 + 1"                 "    saveRDS(result, \"result.rds\")"
#> [5] "}"                                   "EOFrmake"

Example rule using inShell():

rule(target = "result.rds",
     build = inShell({ result <- 1 + 1; saveRDS(result, "result.rds") }),
     clean = "$(RM) result.rds")

Note: Overuse of inShell() is not recommended. Prefer separate script files so Make can detect changes.