Source: core/config.js

import {timeFormat} from 'd3-time-format';

import {logger} from './logger';

/**
 * General configuration
 */
export class Config {
    constructor () {
        this._defaultColors = Config._schemeCategory20c;

        /**
         * The default date format for dc.js
         * @type {Function}
         * @default d3.timeFormat('%m/%d/%Y')
         */
        this.dateFormat = timeFormat('%m/%d/%Y');

        this._renderlet = null;

        /**
         * If this boolean is set truthy, all transitions will be disabled, and changes to the charts will happen
         * immediately.
         * @type {Boolean}
         * @default false
         */
        this.disableTransitions = false;
    }

    /**
     * Set the default color scheme for ordinal charts. Changing it will impact all ordinal charts.
     *
     * By default it is set to a copy of
     * `d3.schemeCategory20c` for backward compatibility. This color scheme has been
     * [removed from D3v5](https://github.com/d3/d3/blob/master/CHANGES.md#changes-in-d3-50).
     * In DC 3.1 release it will change to a more appropriate default.
     *
     * @example
     * config.defaultColors(d3.schemeSet1)
     * @param {Array} [colors]
     * @returns {Array|config}
     */
    defaultColors (colors) {
        if (!arguments.length) {
            // Issue warning if it uses _schemeCategory20c
            if (this._defaultColors === Config._schemeCategory20c) {
                logger.warnOnce('You are using d3.schemeCategory20c, which has been removed in D3v5. ' +
                    'See the explanation at https://github.com/d3/d3/blob/master/CHANGES.md#changes-in-d3-50. ' +
                    'DC is using it for backward compatibility, however it will be changed in DCv3.1. ' +
                    'You can change it by calling dc.config.defaultColors(newScheme). ' +
                    'See https://github.com/d3/d3-scale-chromatic for some alternatives.');
            }
            return this._defaultColors;
        }
        this._defaultColors = colors;
        return this;
    }

}

// D3v5 has removed schemeCategory20c, copied here for backward compatibility
Config._schemeCategory20c = [
    '#3182bd', '#6baed6', '#9ecae1', '#c6dbef', '#e6550d',
    '#fd8d3c', '#fdae6b', '#fdd0a2', '#31a354', '#74c476',
    '#a1d99b', '#c7e9c0', '#756bb1', '#9e9ac8', '#bcbddc',
    '#dadaeb', '#636363', '#969696', '#bdbdbd', '#d9d9d9'];

/**
 * General configuration object; see {@link Config} for members.
 */
export const config = new Config();

/**
 * d3.js compatiblity layer
 */
export const d3compat = {
    eventHandler: handler => function eventHandler (a, b) {
        console.warn('No d3.js compatbility event handler registered, defaulting to v6 behavior.');
        handler.call(this, b, a);
    },
    nester: ({key, sortKeys, sortValues, entries}) => {
        throw new Error('No d3.js compatbility nester registered, load v5 or v6 compability layer.');
    },
    pointer: () => { throw new Error('No d3.js compatbility pointer registered, load v5 or v6 compability layer.'); }
};