gauge

A nearly stateless terminal based horizontal gauge / progress bar.

var Gauge = require("gauge")

var gauge = new Gauge()

gauge.show("working…", 0)
setTimeout(() => { gauge.pulse(); gauge.show("working…", 0.25) }, 500)
setTimeout(() => { gauge.pulse(); gauge.show("working…", 0.50) }, 1000)
setTimeout(() => { gauge.pulse(); gauge.show("working…", 0.75) }, 1500)
setTimeout(() => { gauge.pulse(); gauge.show("working…", 0.99) }, 2000)
setTimeout(() => gauge.hide(), 2300)

CHANGES FROM 1.x

Gauge 2.x is breaking release, please see the changelog for details on what's changed if you were previously a user of this module.

THE GAUGE CLASS

This is the typical interface to the module– it provides a pretty fire-and-forget interface to displaying your status information.

var Gauge = require("gauge")

var gauge = new Gauge([stream], [options])

stream – (optional, default STDERR) A stream that progress bar updates are to be written to. Gauge honors backpressure and will pause most writing if it is indicated.
options – (optional) An option object.

Constructs a new gauge. Gauges are drawn on a single line, and are not drawn if stream isn't a tty and a tty isn't explicitly provided.

If stream is a terminal or if you pass in tty to options then we will detect terminal resizes and redraw to fit. We do this by watching for resize events on the tty. (To work around a bug in versions of Node prior to 2.5.0, we watch for them on stdout if the tty is stderr.) Resizes to larger window sizes will be clean, but shrinking the window will always result in some cruft.

IMPORTANT: If you previously were passing in a non-tty stream but you still want output (for example, a stream wrapped by the ansi module) then you need to pass in the tty option below, as gauge needs access to the underlying tty in order to do things like terminal resizes and terminal width detection.

The options object can have the following properties, all of which are optional:

updateInterval: How often gauge updates should be drawn, in milliseconds.
fixedFramerate: Defaults to false on node 0.8, true on everything else. When this is true a timer is created to trigger once every updateInterval ms, when false, updates are printed as soon as they come in but updates more often than updateInterval are ignored. The reason 0.8 doesn't have this set to true is that it can't unref its timer and so it would stop your program from exiting– if you want to use this feature with 0.8 just make sure you call gauge.disable() before you expect your program to exit.
themes: A themeset to use when selecting the theme to use. Defaults to gauge/themes, see the themes documentation for details.
theme: Select a theme for use, it can be a:
- Theme object, in which case the themes is not used.
- The name of a theme, which will be looked up in the current themes object.
- A configuration object with any of hasUnicode, hasColor or platform keys, which if will be used to override our guesses when making a default theme selection.
If no theme is selected then a default is picked using a combination of our best guesses at your OS, color support and unicode support.
template: Describes what you want your gauge to look like. The default is what npm uses. Detailed documentation is later in this document.
hideCursor: Defaults to true. If true, then the cursor will be hidden while the gauge is displayed.
tty: The tty that you're ultimately writing to. Defaults to the same as stream. This is used for detecting the width of the terminal and resizes. The width used is tty.columns - 1. If no tty is available then a width of 79 is assumed.
enabled: Defaults to true if tty is a TTY, false otherwise. If true the gauge starts enabled. If disabled then all update commands are ignored and no gauge will be printed until you call .enable().
Plumbing: The class to use to actually generate the gauge for printing. This defaults to require('gauge/plumbing') and ordinarily you shouldn't need to override this.
cleanupOnExit: Defaults to true. Ordinarily we register an exit handler to make sure your cursor is turned back on and the progress bar erased when your process exits, even if you Ctrl-C out or otherwise exit unexpectedly. You can disable this and it won't register the exit handler.

`gauge.show(section | status, [completed])`

The first argument is either the section, the name of the current thing contributing to progress, or an object with keys like section, subsection & completed (or any others you have types for in a custom template). If you don't want to update or set any of these you can pass null and it will be ignored.

The second argument is the percent completed as a value between 0 and 1. Without it, completion is just not updated. You'll also note that completion can be passed in as part of a status object as the first argument. If both it and the completed argument are passed in, the completed argument wins.

`gauge.hide([cb])`

Removes the gauge from the terminal. Optionally, callback cb after IO has had an opportunity to happen (currently this just means after setImmediate has called back.)

It turns out this is important when you're pausing the progress bar on one filehandle and printing to another– otherwise (with a big enough print) node can end up printing the "end progress bar" bits to the progress bar filehandle while other stuff is printing to another filehandle. These getting interleaved can cause corruption in some terminals.

`gauge.pulse([subsection])`

subsection – (optional) The specific thing that triggered this pulse

Spins the spinner in the gauge to show output. If subsection is included then it will be combined with the last name passed to gauge.show.

`gauge.disable()`

Hides the gauge and ignores further calls to show or pulse.

`gauge.enable()`

Shows the gauge and resumes updating when show or pulse is called.

`gauge.isEnabled()`

Returns true if the gauge is enabled.

`gauge.setThemeset(themes)`

Change the themeset to select a theme from. The same as the themes option used in the constructor. The theme will be reselected from this themeset.

`gauge.setTheme(theme)`

Change the active theme, will be displayed with the next show or pulse. This can be:

Theme object, in which case the themes is not used.
The name of a theme, which will be looked up in the current themes object.
A configuration object with any of hasUnicode, hasColor or platform keys, which if will be used to override our guesses when making a default theme selection.

If no theme is selected then a default is picked using a combination of our best guesses at your OS, color support and unicode support.

`gauge.setTemplate(template)`

Change the active template, will be displayed with the next show or pulse

Tracking Completion

If you have more than one thing going on that you want to track completion of, you may find the related are-we-there-yet helpful. It's change event can be wired up to the show method to get a more traditional progress bar interface.

THEMES

var themes = require('gauge/themes')

// fetch the default color unicode theme for this platform
var ourTheme = themes({hasUnicode: true, hasColor: true})

// fetch the default non-color unicode theme for osx
var ourTheme = themes({hasUnicode: true, hasColor: false, platform: 'darwin'})

// create a new theme based on the color ascii theme for this platform
// that brackets the progress bar with arrows
var ourTheme = themes.newTheme(themes({hasUnicode: false, hasColor: true}), {
  preProgressbar: '→',
  postProgressbar: '←'
})

The object returned by gauge/themes is an instance of the ThemeSet class.

var ThemeSet = require('gauge/theme-set')
var themes = new ThemeSet()
// or
var themes = require('gauge/themes')
var mythemes = themes.newThemeSet() // creates a new themeset based on the default themes

themes(opts)

themes.getDefault(opts)

Theme objects are a function that fetches the default theme based on platform, unicode and color support.

Options is an object with the following properties:

hasUnicode - If true, fetch a unicode theme, if no unicode theme is available then a non-unicode theme will be used.
hasColor - If true, fetch a color theme, if no color theme is available a non-color theme will be used.
platform (optional) - Defaults to process.platform. If no platform match is available then fallback is used instead.

If no compatible theme can be found then an error will be thrown with a code of EMISSINGTHEME.

themes.addTheme(themeName, themeObj)

themes.addTheme(themeName, [parentTheme], newTheme)

Adds a named theme to the themeset. You can pass in either a theme object, as returned by themes.newTheme or the arguments you'd pass to themes.newTheme.

themes.getThemeNames()

Return a list of all of the names of the themes in this themeset. Suitable for use in themes.getTheme(…).

themes.getTheme(name)

Returns the theme object from this theme set named name.

If name does not exist in this themeset an error will be thrown with a code of EMISSINGTHEME.

themes.setDefault([opts], themeName)

opts is an object with the following properties.

platform - Defaults to 'fallback'. If your theme is platform specific, specify that here with the platform from `process

Gauge

Install / Use

README