itsjavi/bootstrap-colorpicker

useAlpha changes formats from RGBA to RGB if alpha is 1

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#322 opened on Dec 7, 2020

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bughelp wanted

Description

Description

If the config useAlpha=true has been set, an alpha value of 1 is excluded from the result. This is a bug because it means that the tool returns RGBA formatted data only when there is an alpha value less than one, but if the alpha is 1 (100% opaque) then the result format is changed to simple RGB.

While this functionality may be acceptable for some loosely-defined use cases (web designers), it is opinionated compared to earlier versions of colorpicker and now violates the rule of lease surprise.

If this is truly intended(?) by the author, there should be a way to enforce that the format selected in the options is the one used. ie. forceFormat: true

Context

  • bootstrap-colorpicker version: 3.2.0
  • bootstrap version: 4.5.3
  • jQuery version: 3.5.1
  • Browser name and version: Crome/Brave Chromium 87.0.4280.88 (Official Build) (x86_64)
  • Operative System name an version: OSX 10.15.7

Expected behavior

The flags userAlpha and format when used in combination should ALWAYS set the result value to an RGBA formatted string.

	$('.colorpicker').colorpicker({
		format: "rgba",
		useAlpha: true
	});

Actual behavior

The format of the returned string becomes RBG (no alpha) if the alpha value is 1

Live Example

This is visible on the project's own demo page on any of the examples that return RGB(and sometimes A) https://itsjavi.com/bootstrap-colorpicker/tutorial-Basics.html

Contributor guide

Tech stack
javascripthtmlcss
Domain
frontend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
JavaScriptHTMLCSSBootstrap colorpicker basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
Locate the code in the bootstrap colorpicker plugin where the output format is determined based on alpha (likely in the core JavaScript file, e.g., `colorpicker.js`). The bug occurs when `useAlpha: true` and `format: "rgba"`; alpha=1 incorrectly returns RGB instead of RGBA. Investigate the conditional logic that strips alpha when it equals 1. Modify it to always return RGBA when the config demands it. Consider adding an optional `forceFormat` setting if backward compatibility is a concern. Check the demo page and existing comments for context.