gauge

gauge

A nearly stateless terminal based horizontal guage / progress bar.

var Gauge = require("gauge")

var gauge = new Gauge()

gauge.show("test", 0.20)

gauge.pulse("this")

gauge.hide()

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

• options – (optional) An option object. (See below for details.)
• ansiStream – (optional) A stream that's been blessed by the ansi module to include various commands for controlling the cursor in a terminal.

Constructs a new gauge. Gauges are drawn on a single line, and are not drawn if the current terminal isn't a tty.

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

• maxUpdateFrequency: defaults to 50 msec, the gauge will not be drawn more than once in this period of time. This applies to show and pulse calls, but if you hide and then show the gauge it will draw it regardless of time since last draw.
• theme: defaults to Gauge.unicodeif the terminal supports unicode according to [has-unicode], otherwise it defaults toGauge.ascii`. Details on the theme object are documented elsewhere.
• template: see documentation elsewhere for defaults and details.

If ansiStream isn't passed in, then one will be constructed from stderr with ansi(process.stderr).

gauge.show([name, [completed]])

• name – (optional) The name of the current thing contributing to progress. Defaults to the last value used, or "".
• completed – (optional) The portion completed as a value between 0 and 1. Defaults to the last value used, or 0.

If process.stdout.isTTY is false then this does nothing. If completed is 0 and gauge.pulse has never been called, then similarly nothing will be printed.

If maxUpdateFrequency msec haven't passed since the last call to show or pulse then similarly, nothing will be printed. (Actually, the update is deferred until maxUpdateFrequency msec have passed and if nothing else has happened, the gauge update will happen.)

gauge.hide()

Removes the gauge from the terminal.

gauge.pulse([name])

• name – (optional) The specific thing that triggered this pulse

Spins the spinner in the gauge to show output. If name is included then it will be combined with the last name passed to gauge.show using the subsection property of the theme (typically a right facing arrow).

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.setTheme(theme)

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

gauge.setTemplate(template)

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

Theme Objects

There are two theme objects available as a part of the module, Gauge.unicode and Gauge.ascii. Theme objects have the follow properties:

Property	Unicode	ASCII
startgroup	╢	|
endgroup	╟	|
complete	█	#
incomplete	░	-
spinner	▀▐▄▌	-\|/
subsection	→	->

startgroup, endgroup and subsection can be as many characters as you want.

complete and incomplete should be a single character width each.

spinner is a list of characters to use in turn when displaying an activity spinner. The Gauge will spin as many characters as you give here.

Template Objects

A template is an array of objects and strings that, after being evaluated, will be turned into the gauge line. The default template is:

[
    {type: "name", separated: true, maxLength: 25, minLength: 25, align: "left"},
    {type: "spinner", separated: true},
    {type: "startgroup"},
    {type: "completionbar"},
    {type: "endgroup"}
]

The various template elements can either be plain strings, in which case they will be be included verbatum in the output.

If the template element is an object, it can have the following keys:

• type can be:
  • name – The most recent name passed to show; if this is in response to a pulse then the name passed to pulse will be appended along with the subsection property from the theme.
  • spinner – If you've ever called pulse this will be one of the characters from the spinner property of the theme.
  • startgroup – The startgroup property from the theme.
  • completionbar – This progress bar itself
  • endgroup – The endgroup property from the theme.
• separated – If true, the element will be separated with spaces from things on either side (and margins count as space, so it won't be indented), but only if its included.
• maxLength – The maximum length for this element. If its value is longer it will be truncated.
• minLength – The minimum length for this element. If its value is shorter it will be padded according to the align value.
• align – (Default: left) Possible values "left", "right" and "center". Works as you'd expect from word processors.
• length – Provides a single value for both minLength and maxLength. If both length and *minLength or maxLength are specifed then the latter take precedence.

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.