Package 'erratum'

Title: Handle Error and Warning Messages
Description: Elegantly handle error and warning messages.
Authors: John Coene [aut, cre], Opifex [cph]
Maintainer: John Coene <[email protected]>
License: AGPL-3
Version: 2.2.0.9000
Built: 2024-10-31 04:35:45 UTC
Source: https://github.com/devOpifex/erratum

Help Index

Take a Bash

Description

Equivalent to tryCatch().

Usage

bash(expr, e = NULL, w = NULL)

Arguments

expr

Expression to run, passed to tryCatch().
e, w

An object of class Error or Warning as returned by e() or w().

Examples

safe_log <- function(x){
 result <- bash(log(x))
 
 if(is.e(result))
   stop(result$stop())

 return(result)
} 

if(interactive())
 safe_log("a")

Check

Description

Check whether an object is an error or a warning.

Usage

is.e(obj)

## Default S3 method:
is.e(obj)

## S3 method for class 'err'
is.e(obj)

is.w(obj)

## Default S3 method:
is.w(obj)

## S3 method for class 'err'
is.w(obj)

is.problem(obj)

Arguments

obj

Object to check.

Value

A boolean value.

Functions

  • is.e: Whether the object is an error.

  • is.w: Whether the object is a warning.

  • is.problem: Whether the object is an error or a warning.

Examples

err <- e("Whoops!")

is.e(err)
is.w(err)

Check

Description

Checks individual objects.

Usage

chk(obj)

## Default S3 method:
chk(obj)

## S3 method for class 'err'
chk(obj)

Arguments

obj

Object to check.

Details

Runs warning() or stop() where necessary.

Observe with Error Handling

Description

Observe with erratum error handling.

Usage

e.observe(
  x,
  e = NULL,
  w = NULL,
  env = parent.frame(),
  ...,
  label = NULL,
  suspended = FALSE,
  priority = 0,
  domain = shiny::getDefaultReactiveDomain(),
  autoDestroy = TRUE,
  ..stacktraceon = TRUE
)

Arguments

x

An expression (quoted or unquoted). Any return value will be ignored.
e

Error handler.
w

Warning handler.
env

The parent environment for the reactive expression. By default, this is the calling environment, the same as when defining an ordinary non-reactive expression. If x is a quosure and quoted is TRUE, then env is ignored.
...

Not used.
label

A label for the observer, useful for debugging.
suspended

If TRUE, start the observer in a suspended state. If FALSE (the default), start in a non-suspended state.
priority

An integer or numeric that controls the priority with which this observer should be executed. A higher value means higher priority: an observer with a higher priority value will execute before all observers with lower priority values. Positive, negative, and zero values are allowed.
domain

See domains.
autoDestroy

If TRUE (the default), the observer will be automatically destroyed when its domain (if any) ends.
..stacktraceon

Advanced use only. For stack manipulation purposes; see stacktrace().

Observe Event with Error Handling

Description

Observe event with erratum error handling.

Usage

e.observe.event(
  eventExpr,
  handlerExpr,
  e = NULL,
  w = NULL,
  event.env = parent.frame(),
  event.quoted = FALSE,
  handler.env = parent.frame(),
  handler.quoted = FALSE,
  ...,
  label = NULL,
  suspended = FALSE,
  priority = 0,
  domain = shiny::getDefaultReactiveDomain(),
  autoDestroy = TRUE,
  ignoreNULL = TRUE,
  ignoreInit = FALSE,
  once = FALSE
)

Arguments

eventExpr

A (quoted or unquoted) expression that represents the event; this can be a simple reactive value like input$click, a call to a reactive expression like dataset(), or even a complex expression inside curly braces
handlerExpr

The expression to call whenever eventExpr is invalidated. This should be a side-effect-producing action (the return value will be ignored). It will be executed within an isolate() scope.
e

Error handler.
w

Warning handler.
event.env

The parent environment for the reactive expression. By default, this is the calling environment, the same as when defining an ordinary non-reactive expression. If eventExpr is a quosure and event.quoted is TRUE, then event.env is ignored.
event.quoted

If it is TRUE, then the quote()ed value of eventExpr will be used when eventExpr is evaluated. If eventExpr is a quosure and you would like to use its expression as a value for eventExpr, then you must set event.quoted to TRUE.
handler.env

The parent environment for the reactive expression. By default, this is the calling environment, the same as when defining an ordinary non-reactive expression. If handlerExpr is a quosure and handler.quoted is TRUE, then handler.env is ignored.
handler.quoted

If it is TRUE, then the quote()ed value of handlerExpr will be used when handlerExpr is evaluated. If handlerExpr is a quosure and you would like to use its expression as a value for handlerExpr, then you must set handler.quoted to TRUE.
...

Currently not used.
label

A label for the observer or reactive, useful for debugging.
suspended

If TRUE, start the observer in a suspended state. If FALSE (the default), start in a non-suspended state.
priority

An integer or numeric that controls the priority with which this observer should be executed. An observer with a given priority level will always execute sooner than all observers with a lower priority level. Positive, negative, and zero values are allowed.
domain

See domains.
autoDestroy

If TRUE (the default), the observer will be automatically destroyed when its domain (if any) ends.
ignoreNULL

Whether the action should be triggered (or value calculated, in the case of eventReactive) when the input event expression is NULL. See Details.
ignoreInit

If TRUE, then, when this observeEvent is first created/initialized, ignore the handlerExpr (the second argument), whether it is otherwise supposed to run or not. The default is FALSE. See Details.
once

Whether this observeEvent should be immediately destroyed after the first time that the code in handlerExpr is run. This pattern is useful when you want to subscribe to a event that should only happen once.

Error

Description

Error

Error

Super class

erratum::Issue -> Error

Methods

Public methods

Inherited methods

Method new()

Usage
Error$new(obj, raiser = getOption("ERR_RAISER_ERROR", stopper))
Arguments
obj

A character string or an object of class error, or warning.

raiser

Template to raise the issue.

Details

Initialise

Method stop()

Usage
Error$stop()
Details

Stop

Analogous to stop()

Method fatal()

Usage
Error$fatal()
Details

Fatal

Analogous to stop()

Method clone()

The objects of this class are cloneable with this method.

Usage
Error$clone(deep = FALSE)
Arguments
deep

Whether to make a deep clone.

Handlers

Description

Handle errors and warnings.

Usage

e(obj)

w(obj)

Arguments

obj

A character string or an object of class error, or warning.

Examples

err <- e("Something went wrong")

foo <- function(x){
 if(is.character(x))
   return(err)

 log(x)
}

foo("a")

Extract Call

Description

Extract call from error and warnings.

Usage

get_call(obj)

Arguments

obj

Message string, object of class error, or warning.

Extract Message

Description

Extract message from error and warnings.

Usage

get_msg(obj)

Arguments

obj

Message string, object of class error, or warning.

Core Class

Description

Core class to create and handle issues.

Active bindings

rule

Rules to perform checks, must be functions that accept a single argument and return a boolean.

message

The message (warning or error).

call

Expression or function (as string) that led to the issue.

raiser

Function to run when the raise method is called. By default the error uses stop() and warning uses warning(). The function must accept a single argument: the error message (character vector).

Methods

Public methods

Method new()

Usage
Issue$new(obj, type = c("error", "warning"))
Arguments
obj

A character string or an object of class error, or warning.

type

Type of message.

Details

Initialise

Method print()

Usage
Issue$print()
Details

Print

Print message of error or warning.

Method return()

Usage
Issue$return(n = 1)
Arguments
n

the number of generations to go back, passed to parent.frame().

Details

Return Returns self from parent function.

Method addRule()

Usage
Issue$addRule(fn)
Arguments
fn

Function defining rule, must accept a single argument and return a boolean.

Details

Add a rule

Method check()

Usage
Issue$check(obj)
Arguments
obj

Object to check by rules

Details

Add a predicate

Method raise()

Usage
Issue$raise(fn = NULL)
Arguments
fn

A function to use to raise the issue.

Details

Raise error or warning

Method clone()

The objects of this class are cloneable with this method.

Usage
Issue$clone(deep = FALSE)
Arguments
deep

Whether to make a deep clone.

Latch an Error or a Warning

Description

Latch an error or a warning to an object to indicate an issue associated with it. These can later be checked with is.e() and is.w(), and can also be resolve().

Usage

latch.e(obj, error)

latch.w(obj, warning)

unlatch(obj)

Arguments

obj

Object to latch the error or warning onto.
error, warning

Error or warning, the output of e() or w().

Functions

  • latche and latchw: latch an error or a warning.

  • unlatch: unlatch any error or warning.

Examples

x <- 1
problematic <- latch.e(x, e("Not right"))

is.e(problematic)

do_sth_with_x <- function(x){
 resolve(x)
 x + 1
}

if(interactive()){
 do_sth_with_x(x)
 do_sth_with_x(problematic)
}

unlatch(problematic)

Raisers

Description

Set raise method globally, every subsequent raise method will make use of this function.

Usage

raise.e(fn = NULL)

raise.w(fn = NULL)

Arguments

fn

Function to run when the raise method is called. By default the error uses stop() and warning uses warning(). The function must accept a single argument: the error message (character vector).

Resolve Errors and Warnings

Description

Resolve Errors and Warnings

Usage

resolve(...)

defer_resolve(...)

Arguments

...

Objects to check, if any of them is an Error then stop() is called, if any are Warnings then warning() is called.

Details

Objects passed are evalutated in order.

Value

Invisiby returns NULL

Templates

Description

Define error and warning templates.

Usage

template.e(pat = "%s")

template.w(pat = "%s")

Arguments

pat

Pattern to use, must include ⁠%s⁠, forwarded to sprintf().

Examples

msg <- "Something's wrong" 

# default
e(msg)

# template
template.e("Whoops: %s - sorry!")
e(msg)

# reset
template.e()

Error

Description

Error

Error

Super class

erratum::Issue -> Warning

Methods

Public methods

Inherited methods

Method new()

Usage
Warning$new(obj, raiser = getOption("ERR_RAISER_WARNING", warner))
Arguments
obj

A character string or an object of class error, or warning.

raiser

Template to raise the issue.

Details

Initialise

Method warn()

Usage
Warning$warn()
Details

Warn

Analogous to warning()

Method clone()

The objects of this class are cloneable with this method.

Usage
Warning$clone(deep = FALSE)
Arguments
deep

Whether to make a deep clone.