Advanced Usage Patterns
This vignette covers more advanced usage patterns for the
myrpackage functions.
Creating Custom Greeting Functions
You can create custom greeting functions based on
hello() and goodbye() to maintain consistent
greetings throughout your application:
# Create a custom Spanish greeter
spanish_hello <- function(name = "amigos", exclamation = TRUE, capitalize = FALSE) {
hello(name = name, language = "spanish", exclamation = exclamation, capitalize = capitalize)
}
# Try it out
spanish_hello("todos")
#> Hola, todos!
spanish_hello("R usuarios", capitalize = TRUE)
#> Hola, R usuarios!Working with Multiple Languages
If your application needs to support multiple languages, you can create a wrapper function:
multilingual_greeting <- function(name, languages = c("english", "spanish", "french")) {
for (lang in languages) {
hello(name = name, language = lang)
}
}
# Greet in multiple languages
multilingual_greeting("R users", c("english", "french", "german"))
#> Hello, R users!
#> Bonjour, R users!
#> Hallo, R users!Creating Personalized Messages
You can combine the greeting functions with other text to create more personalized messages:
create_welcome_message <- function(name, language = "english") {
greeting <- suppressMessages(hello(name, language, exclamation = TRUE))
# Add a personalized message
additional_text <- switch(
language,
english = "Welcome to our application.",
spanish = "Bienvenido a nuestra aplicación.",
french = "Bienvenue dans notre application.",
portuguese = "Bem-vindo ao nosso aplicativo.",
german = "Willkommen in unserer Anwendung.",
italian = "Benvenuto nella nostra applicazione.",
"Welcome to our application."
)
message <- paste(greeting, additional_text)
cat(message, "\n")
invisible(message)
}
# Create a welcome message
create_welcome_message("John", "english")
#> Hello, John!
#> Hello, John! Welcome to our application.
create_welcome_message("Maria", "spanish")
#> Hola, Maria!
#> Hola, Maria! Bienvenido a nuestra aplicación.Error Handling
When working with user input, it’s good practice to handle potential errors:
safe_hello <- function(name, language) {
tryCatch(
{
hello(name, language)
},
error = function(e) {
cat("Error in greeting:", conditionMessage(e), "\n")
cat("Using default greeting instead.\n")
hello()
},
warning = function(w) {
cat("Warning:", conditionMessage(w), "\n")
# Continue execution with the warning
suppressWarnings(hello(name, language))
}
)
}
# Test with valid inputs
safe_hello("R users", "english")
#> Hello, R users!
# Test with an invalid language (produces a warning)
safe_hello("R users", "klingon")
#> Warning: Language 'klingon' not supported. Using English instead. Supported languages: english, spanish, french, portuguese, german, italian
#> Hello, R users!
# Test with an invalid name (produces an error)
safe_hello(c("multiple", "names"), "english")
#> Error in greeting: 'name' must be a single character string
#> Using default greeting instead.
#> Hello, world!Integration with Other Packages
You can easily integrate myrpackage functions with other
packages, such as creating a shiny app:
# This is an example, not run
library(shiny)
ui <- fluidPage(
titlePanel("Multilingual Greeter"),
sidebarLayout(
sidebarPanel(
textInput("name", "Your Name:", "world"),
selectInput("language", "Language:",
choices = c("English" = "english",
"Spanish" = "spanish",
"French" = "french",
"Portuguese" = "portuguese",
"German" = "german",
"Italian" = "italian")),
checkboxInput("exclamation", "Add Exclamation Mark", TRUE),
checkboxInput("capitalize", "Capitalize Name", FALSE)
),
mainPanel(
h3("Greeting:"),
verbatimTextOutput("greeting"),
h3("Farewell:"),
verbatimTextOutput("farewell")
)
)
)
server <- function(input, output) {
output$greeting <- renderText({
suppressMessages(
hello(input$name, input$language, input$exclamation, input$capitalize)
)
})
output$farewell <- renderText({
suppressMessages(
goodbye(input$name, input$language, input$exclamation, input$capitalize)
)
})
}
# shinyApp(ui = ui, server = server)Performance Considerations
For high-volume applications, you might want to avoid printing to the console:
# Create a silent version of hello() that doesn't print to console
silent_hello <- function(name = "world", language = "english", exclamation = TRUE, capitalize = FALSE) {
# Input validation - simplified for brevity
if (!is.character(name) || length(name) != 1) {
stop("'name' must be a single character string")
}
# Capitalize name if requested
if (capitalize) {
name <- paste0(toupper(substr(name, 1, 1)), substr(name, 2, nchar(name)))
}
# Select greeting based on language
greeting <- switch(
language,
english = "Hello",
spanish = "Hola",
french = "Bonjour",
portuguese = "Olá",
german = "Hallo",
italian = "Ciao",
"Hello"
)
# Construct the greeting
result <- paste0(greeting, ", ", name)
# Add exclamation mark if requested
if (exclamation) {
result <- paste0(result, "!")
} else {
result <- paste0(result, ".")
}
# Return the greeting (without printing)
return(result)
}
# Use the silent version
greeting <- silent_hello("R users", "french")
greeting
#> [1] "Bonjour, R users!"Batch Processing
You can use the greeting functions in batch processing scenarios:
# Create greetings for a list of names
names <- c("Alice", "Bob", "Charlie", "David")
languages <- c("english", "spanish", "french", "portuguese")
# Create a dataframe with all combinations
greetings_df <- expand.grid(name = names, language = languages, stringsAsFactors = FALSE)
# Add greetings
greetings_df$greeting <- mapply(
function(name, language) {
suppressMessages(hello(name, language))
},
greetings_df$name,
greetings_df$language
)
#> Hello, Alice!
#> Hello, Bob!
#> Hello, Charlie!
#> Hello, David!
#> Hola, Alice!
#> Hola, Bob!
#> Hola, Charlie!
#> Hola, David!
#> Bonjour, Alice!
#> Bonjour, Bob!
#> Bonjour, Charlie!
#> Bonjour, David!
#> Olá, Alice!
#> Olá, Bob!
#> Olá, Charlie!
#> Olá, David!
# Display the first few rows
head(greetings_df)
#> name language greeting
#> 1 Alice english Hello, Alice!
#> 2 Bob english Hello, Bob!
#> 3 Charlie english Hello, Charlie!
#> 4 David english Hello, David!
#> 5 Alice spanish Hola, Alice!
#> 6 Bob spanish Hola, Bob!