@lunaticmuch/front-matter-manipulator/lib/core/fields.js

A utility for parsing and manipulating documents with Front Matter

import _  from 'lodash';
import deepmerge  from 'deepmerge';
import filterByField  from '../util/filterByField.js';
import getFiles  from '../util/getFiles.js';
import getFieldPermutations  from '../util/getFieldPermutations.js';
import isMissing  from '../util/isMissing.js';
import output  from './output.js';
import parseFile  from '../util/parseFile.js';
import uniqueKeys  from '../util/uniqueKeys.js';
/** @namespace Fields */

/**
 * Retrieves all fields for one or more files
 * @memberof Fields
 * @param {string} patterns - A file path or glob pattern to search for files
 * @param {Object} options - Configuration options
 * @param {string} options.ignore - A file path or glob pattern to search for files not to modify. Defaults to "node_modules".
 * @param {string} options.exclude - Exclude files that have a certain values. Formatted as a comma delimited list of key value pairs.
 * @param {string} options.include - Only include files that have a certain values. Formatted as a comma delimited list of key value pairs.
 * @param {string} options.outputFile - path to a file where output should be saved
 * @param {string} options.outputstring - output values as a space delimited string instead of JSON
 * @returns {Object} fields
 * @example
 * var fmp = require("front-matter-manipulator")
 *  
 * fmp.fields("_posts/example-post.md")
 * @example
 * var fmp = require("front-matter-manipulator")
 * var options = {
 *     ignore: "_posts/subdirectory/*.md",
 *     include: "layout=post",
 *     exclude: "featured=true"
 * }
 *  
 * fmp.fields("**‏/*.md", options)
 */

export default function fields(patterns, options) {
    if (!patterns) throw new Error('Missing value for "patterns". Please provide a file path or glob pattern');

    const defaultOptions = {
        exclude: '',
        include: ''
    };

    options = Object.assign(defaultOptions, options);

    if (options.exclude) {
        let filters = options.exclude.split(',');
        options.exclude = filters.map(function(f) {
            return f.split('=');
        });
    } else {
        options.exclude = [];
    }

    if (options.include) {
        let filters = options.include.split(',');
        options.include = filters.map(function(f) {
            return f.split('=');
        });
    } else {
        options.include = [];
    }
    
    var matchData = [];
    var files = getFiles(patterns, options.ignore);

    if(files.length > 0) {
        var rawMatches = files.reduce(function(results, f) {
            if (!isMissing(f.file)) {
                var {data} = parseFile(f.file);
                results.push(data);
            }
            return results;
        }, []);

        if (options.exclude.length > 0) {
            rawMatches = filterByField(options.exclude, rawMatches, true);
        }

        if (options.include.length > 0) {
            rawMatches = filterByField(options.include, rawMatches);
        }

        var cleanData = rawMatches.filter(function(n) {
            return !isMissing(n);
        });

        matchData = deepmerge.all(cleanData, { arrayMerge: uniqueKeys});

        matchData = Object.keys(matchData).map(function(k) {
            var cleanRegex = /\.\d|\\"/gi;
            var value = getFieldPermutations(k, matchData);
            if (typeof value[0] == 'string')
                value = value[0].replace(cleanRegex, '');
            return value;
        }).reduce(function(a, b) {
            return a.concat(b);
        }, []).filter(function(k) {
            return !isMissing(k);
        });

        matchData = _.uniq(matchData);
    }

    return output(matchData, options);
}