Class: Toys::CLI

Inherits:
Object
  • Object
show all
Defined in:
lib/toys/cli.rb

Overview

A Toys-based CLI.

This is the entry point for command line execution. It includes the set of tool definitions (and/or information on how to load them from the file system), configuration parameters such as logging and error handling, and a method to call to invoke a command.

This is the class to instantiate to create a Toys-based command line executable. For example:

#!/usr/bin/env ruby
require "toys-core"
cli = Toys::CLI.new
cli.add_config_block do
  def run
    puts "Hello, world!"
  end
end
exit(cli.run(*ARGV))

The currently running CLI is also available at runtime, and can be used by tools that want to invoke other tools. For example:

# My .toys.rb
tool "foo" do
  def run
    puts "in foo"
  end
end
tool "bar" do
  def run
    puts "in bar"
    cli.run "foo"
  end
end

Defined Under Namespace

Classes: DefaultCompletion, DefaultErrorHandler

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(executable_name: nil, middleware_stack: nil, extra_delimiters: "", config_dir_name: nil, config_file_name: nil, index_file_name: nil, preload_file_name: nil, preload_dir_name: nil, data_dir_name: nil, mixin_lookup: nil, middleware_lookup: nil, template_lookup: nil, logger: nil, base_level: nil, error_handler: nil, completion: nil) ⇒ CLI

Create a CLI.

Most configuration parameters (besides tool definitions and tool lookup paths) are set as options passed to the constructor. These options fall roughly into four categories:

  • Options affecting output behavior:
    • logger: The logger
    • base_level: The default log level
    • error_handler: Callback for handling exceptions
    • executable_name: The name of the executable
  • Options affecting tool specification
    • extra_delimibers: Tool name delimiters besides space
    • completion: Tab completion handler
  • Options affecting tool definition
    • middleware_stack: The middleware applied to all tools
    • mixin_lookup: Where to find well-known mixins
    • middleware_lookup: Where to find well-known middleware
    • template_lookup: Where to find well-known templates
  • Options affecting tool files and directories
    • config_dir_name: Directory name containing tool files
    • config_file_name: File name for tools
    • index_file_name: Name of index files in tool directories
    • preload_file_name: Name of preload files in tool directories
    • preload_dir_name: Name of preload directories in tool directories
    • data_dir_name: Name of data directories in tool directories

Parameters:

  • logger (Logger) —

    The logger to use. Optional. If not provided, will use a default logger that writes formatted output to STDERR, as defined by default_logger.

  • base_level (Integer) —

    The logger level that should correspond to zero verbosity. Optional. If not provided, defaults to the current level of the logger (which is often Logger::WARN).

  • error_handler (Proc, nil) —

    A proc that is called when an error is caught. The proc should take a Toys::ContextualError argument and report the error. It should return an exit code (normally nonzero). Optional. If not provided, defaults to an instance of DefaultErrorHandler, which displays an error message to STDERR.

  • executable_name (String) —

    The executable name displayed in help text. Optional. Defaults to the ruby program name.

  • extra_delimiters (String) —

    A string containing characters that can function as delimiters in a tool name. Defaults to empty. Allowed characters are period, colon, and slash.

  • completion (Toys::Completion::Base) —

    A specifier for shell tab completion for the CLI as a whole. Optional. If not provided, defaults to an instance of DefaultCompletion, which delegates completion to the relevant tool.

  • middleware_stack (Array) —

    An array of middleware that will be used by default for all tools loaded by this CLI. Optional. If not provided, uses a default set of middleware defined in default_middleware_stack. To include no middleware, pass the empty array explicitly.

  • mixin_lookup (Toys::ModuleLookup) —

    A lookup for well-known mixin modules (i.e. with symbol names). Optional. If not provided, defaults to the set of standard mixins provided by toys-core, as defined by default_mixin_lookup. If you explicitly want no standard mixins, pass an empty instance of ModuleLookup.

  • middleware_lookup (Toys::ModuleLookup) —

    A lookup for well-known middleware classes. Optional. If not provided, defaults to the set of standard middleware classes provided by toys-core, as defined by default_middleware_lookup. If you explicitly want no standard middleware, pass an empty instance of ModuleLookup.

  • template_lookup (Toys::ModuleLookup) —

    A lookup for well-known template classes. Optional. If not provided, defaults to the set of standard template classes provided by toys core, as defined by default_template_lookup. If you explicitly want no standard tenokates, pass an empty instance of ModuleLookup.

  • config_dir_name (String) —

    A directory with this name that appears in the loader path, is treated as a configuration directory whose contents are loaded into the toys configuration. Optional. If not provided, toplevel configuration directories are disabled. Note: the standard toys executable sets this to ".toys".

  • config_file_name (String) —

    A file with this name that appears in the loader path, is treated as a toplevel configuration file whose contents are loaded into the toys configuration. This does not include "index" configuration files located within a configuration directory. Optional. If not provided, toplevel configuration files are disabled. Note: the standard toys executable sets this to ".toys.rb".

  • index_file_name (String) —

    A file with this name that appears in any configuration directory is loaded first as a standalone configuration file. This does not include "toplevel" configuration files outside configuration directories. Optional. If not provided, index configuration files are disabled. Note: the standard toys executable sets this to ".toys.rb".

  • preload_file_name (String) —

    A file with this name that appears in any configuration directory is preloaded using require before any tools in that configuration directory are defined. A preload file includes normal Ruby code, rather than Toys DSL definitions. The preload file is loaded before any files in a preload directory. Optional. If not provided, preload files are disabled. Note: the standard toys executable sets this to ".preload.rb".

  • preload_dir_name (String) —

    A directory with this name that appears in any configuration directory is searched for Ruby files, which are preloaded using require before any tools in that configuration directory are defined. Files in a preload directory include normal Ruby code, rather than Toys DSL definitions. Files in a preload directory are loaded after any standalone preload file. Optional. If not provided, preload directories are disabled. Note: the standard toys executable sets this to ".preload".

  • data_dir_name (String) —

    A directory with this name that appears in any configuration directory is added to the data directory search path for any tool file in that directory. Optional. If not provided, data directories are disabled. Note: the standard toys executable sets this to ".data".



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# File 'lib/toys/cli.rb', line 185

def initialize(
  executable_name: nil, middleware_stack: nil, extra_delimiters: "",
  config_dir_name: nil, config_file_name: nil, index_file_name: nil,
  preload_file_name: nil, preload_dir_name: nil, data_dir_name: nil,
  mixin_lookup: nil, middleware_lookup: nil, template_lookup: nil,
  logger: nil, base_level: nil, error_handler: nil, completion: nil
)
  @executable_name = executable_name || ::File.basename($PROGRAM_NAME)
  @middleware_stack = middleware_stack || CLI.default_middleware_stack
  @mixin_lookup = mixin_lookup || CLI.default_mixin_lookup
  @middleware_lookup = middleware_lookup || CLI.default_middleware_lookup
  @template_lookup = template_lookup || CLI.default_template_lookup
  @error_handler = error_handler || DefaultErrorHandler.new
  @completion = completion || DefaultCompletion.new
  @logger = logger || CLI.default_logger
  @base_level = base_level || @logger.level
  @extra_delimiters = extra_delimiters
  @config_dir_name = config_dir_name
  @config_file_name = config_file_name
  @index_file_name = index_file_name
  @preload_file_name = preload_file_name
  @preload_dir_name = preload_dir_name
  @data_dir_name = data_dir_name
  @loader = Loader.new(
    index_file_name: @index_file_name, extra_delimiters: @extra_delimiters,
    preload_dir_name: @preload_dir_name, preload_file_name: @preload_file_name,
    data_dir_name: @data_dir_name,
    mixin_lookup: @mixin_lookup, template_lookup: @template_lookup,
    middleware_lookup: @middleware_lookup, middleware_stack: @middleware_stack
  )
end

Instance Attribute Details

#base_level ⇒ Integer (readonly)

The initial logger level in this CLI, used as the level for verbosity 0.

Returns:

  • (Integer) 


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# File 'lib/toys/cli.rb', line 276

def base_level
  @base_level
end

#completion ⇒ Toys::Completion::Base, Proc (readonly)

The overall completion strategy for this CLI.

Returns:



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# File 'lib/toys/cli.rb', line 282

def completion
  @completion
end

#executable_name ⇒ String (readonly)

The effective executable name used for usage text in this CLI.

Returns:

  • (String) 


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# File 'lib/toys/cli.rb', line 258

def executable_name
  @executable_name
end

#extra_delimiters ⇒ String (readonly)

The string of tool name delimiter characters (besides space).

Returns:

  • (String) 


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# File 'lib/toys/cli.rb', line 264

def extra_delimiters
  @extra_delimiters
end

#loader ⇒ Toys::Loader (readonly)

The current loader for this CLI.

Returns:



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# File 'lib/toys/cli.rb', line 252

def loader
  @loader
end

#logger ⇒ Logger (readonly)

The logger used by this CLI.

Returns:

  • (Logger) 


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# File 'lib/toys/cli.rb', line 270

def logger
  @logger
end

Class Method Details

.default_logger(output: nil) ⇒ Logger

Returns a default logger that writes formatted logs to a given stream.

Parameters:

  • output (IO) —

    The stream to output to (defaults to $stderr)

Returns:

  • (Logger) 


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# File 'lib/toys/cli.rb', line 649

def default_logger(output: nil)
  require "toys/utils/terminal"
  output ||= $stderr
  logger = ::Logger.new(output)
  terminal = Utils::Terminal.new(output: output)
  logger.formatter = proc do |severity, time, _progname, msg|
    msg_str =
      case msg
      when ::String
        msg
      when ::Exception
        "#{msg.message} (#{msg.class})\n" << (msg.backtrace || []).join("\n")
      else
        msg.inspect
      end
    format_log(terminal, time, severity, msg_str)
  end
  logger.level = ::Logger::WARN
  logger
end

.default_middleware_lookup ⇒ Toys::ModuleLookup

Returns a default ModuleLookup for middleware that points at the StandardMiddleware module.

Returns:



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# File 'lib/toys/cli.rb', line 630

def default_middleware_lookup
  ModuleLookup.new.add_path("toys/standard_middleware")
end

.default_middleware_stack ⇒ Array<Toys::Middleware>

Returns a default set of middleware that may be used as a starting point for a typical CLI. This set includes the following in order:

Returns:



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# File 'lib/toys/cli.rb', line 605

def default_middleware_stack
  [
    [:set_default_descriptions],
    [:show_help, help_flags: true, fallback_execution: true],
    [:handle_usage_errors],
    [:add_verbosity_flags],
  ]
end

.default_mixin_lookup ⇒ Toys::ModuleLookup

Returns a default ModuleLookup for mixins that points at the StandardMixins module.

Returns:



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# File 'lib/toys/cli.rb', line 620

def default_mixin_lookup
  ModuleLookup.new.add_path("toys/standard_mixins")
end

.default_template_lookup ⇒ Toys::ModuleLookup

Returns a default empty ModuleLookup for templates.

Returns:



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# File 'lib/toys/cli.rb', line 639

def default_template_lookup
  ModuleLookup.new
end

Instance Method Details

#add_config_block(high_priority: false, name: nil, &block) ⇒ self

Add a configuration block to the loader.

This is used to create tools "inline", and is useful for simple command line executables based on Toys.

Parameters:

  • high_priority (Boolean) —

    Add the config at the head of the priority list rather than the tail.

  • name (String) —

    The source name that will be shown in documentation for tools defined in this block. If omitted, a default unique string will be generated.

  • block (Proc) —

    The block of configuration, executed in the context of the tool DSL DSL::Tool.

Returns:

  • (self) 


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# File 'lib/toys/cli.rb', line 319

def add_config_block(high_priority: false, name: nil, &block)
  @loader.add_block(high_priority: high_priority, name: name, &block)
  self
end

#add_config_path(path, high_priority: false) ⇒ self

Add a specific configuration file or directory to the loader.

This is generally used to load a static or "built-in" set of tools, either for a standalone command line executable based on Toys, or to provide a "default" set of tools for a dynamic executable. For example, the main Toys executable uses this to load the builtin tools from its "builtins" directory.

Parameters:

  • path (String) —

    A path to add. May reference a single Toys file or a Toys directory.

  • high_priority (Boolean) —

    Add the config at the head of the priority list rather than the tail.

Returns:

  • (self) 


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# File 'lib/toys/cli.rb', line 299

def add_config_path(path, high_priority: false)
  @loader.add_path(path, high_priority: high_priority)
  self
end

#add_search_path(search_path, high_priority: false) ⇒ self

Checks the given directory path. If it contains a config file and/or config directory, those are added to the loader.

The main Toys executable uses this method to load tools from directories in the TOYS_PATH.

Parameters:

  • search_path (String) —

    A path to search for configs.

  • high_priority (Boolean) —

    Add the configs at the head of the priority list rather than the tail.

Returns:

  • (self) 


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# File 'lib/toys/cli.rb', line 336

def add_search_path(search_path, high_priority: false)
  paths = []
  if @config_file_name
    file_path = ::File.join(search_path, @config_file_name)
    paths << file_path if !::File.directory?(file_path) && ::File.readable?(file_path)
  end
  if @config_dir_name
    dir_path = ::File.join(search_path, @config_dir_name)
    paths << dir_path if ::File.directory?(dir_path) && ::File.readable?(dir_path)
  end
  @loader.add_path(paths, high_priority: high_priority)
  self
end

#add_search_path_hierarchy(start: nil, terminate: [], high_priority: false) ⇒ self

Walk up the directory hierarchy from the given start location, and add to the loader any config files and directories found.

The main Toys executable uses this method to load tools from the current directory and its ancestors.

Parameters:

  • start (String) —

    The first directory to add. Defaults to the current working directory.

  • terminate (Array<String>) —

    Optional list of directories that should terminate the search. If the walk up the directory tree encounters one of these directories, the search is halted without checking the terminating directory.

  • high_priority (Boolean) —

    Add the configs at the head of the priority list rather than the tail.

Returns:

  • (self) 


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# File 'lib/toys/cli.rb', line 367

def add_search_path_hierarchy(start: nil, terminate: [], high_priority: false)
  path = start || ::Dir.pwd
  paths = []
  loop do
    break if terminate.include?(path)
    paths << path
    next_path = ::File.dirname(path)
    break if next_path == path
    path = next_path
  end
  paths.reverse! if high_priority
  paths.each do |p|
    add_search_path(p, high_priority: high_priority)
  end
  self
end

#child(**_opts) {|cli| ... } ⇒ Toys::CLI

Make a clone with the same settings but no paths in the loader. This is sometimes useful for running sub-tools that have to be loaded from a different configuration.

Parameters:

  • _opts (Hash) —

    Unused options that can be used by subclasses.

Yield Parameters:

  • cli (Toys::CLI) —

    If you pass a block, the new CLI is yielded to it so you can add paths and make other modifications.

Returns:



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# File 'lib/toys/cli.rb', line 227

def child(**_opts)
  cli = CLI.new(executable_name: @executable_name,
                config_dir_name: @config_dir_name,
                config_file_name: @config_file_name,
                index_file_name: @index_file_name,
                preload_dir_name: @preload_dir_name,
                preload_file_name: @preload_file_name,
                data_dir_name: @data_dir_name,
                middleware_stack: @middleware_stack,
                extra_delimiters: @extra_delimiters,
                mixin_lookup: @mixin_lookup,
                middleware_lookup: @middleware_lookup,
                template_lookup: @template_lookup,
                logger: @logger,
                base_level: @base_level,
                error_handler: @error_handler,
                completion: @completion)
  yield cli if block_given?
  cli
end

#run(*args, verbosity: 0, delegated_from: nil) ⇒ Integer

Run the CLI with the given command line arguments. Handles exceptions using the error handler.

Parameters:

  • args (String...) —

    Command line arguments specifying which tool to run and what arguments to pass to it. You may pass either a single array of strings, or a series of string arguments.

  • verbosity (Integer) —

    Initial verbosity. Default is 0.

Returns:

  • (Integer) —

    The resulting process status code (i.e. 0 for success).



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# File 'lib/toys/cli.rb', line 395

def run(*args, verbosity: 0, delegated_from: nil)
  tool, remaining = ContextualError.capture("Error finding tool definition") do
    @loader.lookup(args.flatten)
  end
  ContextualError.capture_path(
    "Error during tool execution!", tool.source_info&.source_path,
    tool_name: tool.full_name, tool_args: remaining
  ) do
    default_data = {
      Context::Key::VERBOSITY => verbosity,
      Context::Key::DELEGATED_FROM => delegated_from,
    }
    run_tool(tool, remaining, default_data)
  end
rescue ContextualError, ::Interrupt => e
  @error_handler.call(e).to_i
end