@nicodoggie/kingraph/lib/apply_style.js

Plots family trees using JavaScript and Graphviz

const map = require('object-loops/map');
const assign = require('object-assign');
const reduce = require('object-loops/reduce');
const values = require('object-loops/values');
const DEFAULT_STYLES = require('./defaults/styles');

/**
 * Returns attributes for a given class
 *
 *     data = { styles: { ':root': { color: 'gold', dir: 'none' } } }
 *     applyStyle(data, [':root'])
 *     => ['color="gold"', 'dir="none"']
 */

function applyStyle (data, classes, options) {
    if (!options) options = {};

    const styles = data.styles || {};

    function applyStyles (acc, stylesheet) {
        return reduce(stylesheet, (styles, val, key) => {
            if (classes.indexOf(key) === -1) return styles;
            return assign({}, styles, val);
        }, acc);
    }

    let result = {};
    result = assign({}, result, options.before || {});
    result = applyStyles(result, DEFAULT_STYLES);
    result = applyStyles(result, data.styles || {});
    result = assign({}, result, options.after || {});
    return renderStyle(result, options);
}

/**
 * Renders key/value into an attribute string
 *
 *     renderStyle({ color: 'gold', dir: 'none' ])
 *     => ['color="gold"', 'dir="none"']
 */

function renderStyle (properties, options) {
    return values(map(properties, (val, key) => {
        if (val == null) return;
        return `${key}=${stringify(val)}`;
    })).filter(s => s != null);
}

function stringify (val) {
    if (typeof val === 'string' && /^<.*>$/.test(val)) {
        return val;
    } else {
        return JSON.stringify(val);
    }
}

/*
 * Export
 */

module.exports = applyStyle;