How to use the cordova-common.PlatformJson.load function in cordova-common

function runUninstallPlatform (actions, platform, project_dir, plugin_dir, plugins_dir, options) {
    var pluginInfoProvider = options.pluginInfoProvider;
    // If this plugin is not really installed, return (CB-7004).
    if (!fs.existsSync(plugin_dir)) {
        return Promise.resolve(true);
    }

    var pluginInfo = pluginInfoProvider.get(plugin_dir);
    var plugin_id = pluginInfo.id;

    // Merge cli_variables and plugin.xml variables
    var variables = variableMerge.mergeVariables(plugin_dir, platform, options);

    // Deps info can be passed recusively
    var platformJson = PlatformJson.load(plugins_dir, platform);
    var depsInfo = options.depsInfo || dependencies.generateDependencyInfo(platformJson, plugins_dir, pluginInfoProvider);

    // Check that this plugin has no dependents.
    var dependents = dependencies.dependents(plugin_id, depsInfo, platformJson, pluginInfoProvider);

    if (options.is_top_level && dependents && dependents.length > 0) {
        var msg = 'The plugin \'' + plugin_id + '\' is required by (' + dependents.join(', ') + ')';
        if (options.force) {
            events.emit('warn', msg + ' but forcing removal');
        } else {
            return Promise.reject(new CordovaError(msg + ', skipping uninstallation. (try --force if trying to update)'));
        }
    }

    // Check how many dangling dependencies this plugin has.
    var deps = depsInfo.graph.getChain(plugin_id);

module.exports.prepare = function (cordovaProject, options) {
    var self = this;

    var platformJson = PlatformJson.load(this.locations.root, this.platform);
    var munger = new PlatformMunger(this.platform, this.locations.root, platformJson, new PluginInfoProvider());

    this._config = updateConfigFilesFrom(cordovaProject.projectConfig, munger, this.locations);

    // Update own www dir with project's www assets and plugins' assets and js-files
    return Q.when(updateWww(cordovaProject, this.locations)).then(function () {
        // update project according to config.xml changes.
        return updateProjectAccordingTo(self._config, self.locations);
    }).then(function () {
        updateIcons(cordovaProject, path.relative(cordovaProject.root, self.locations.res));
        updateSplashes(cordovaProject, path.relative(cordovaProject.root, self.locations.res));
        updateFileResources(cordovaProject, path.relative(cordovaProject.root, self.locations.root));
    }).then(function () {
        events.emit('verbose', 'Prepared android project successfully');
    });
};

function runUninstallPlatform(actions, platform, project_dir, plugin_dir, plugins_dir, options) {
    var pluginInfoProvider = options.pluginInfoProvider;
    // If this plugin is not really installed, return (CB-7004).
    if (!fs.existsSync(plugin_dir)) {
        return Q(true);
    }

    var pluginInfo = pluginInfoProvider.get(plugin_dir);
    var plugin_id = pluginInfo.id;

    // Deps info can be passed recusively
    var platformJson = PlatformJson.load(plugins_dir, platform);
    var depsInfo = options.depsInfo || dependencies.generateDependencyInfo(platformJson, plugins_dir, pluginInfoProvider);

    // Check that this plugin has no dependents.
    var dependents = dependencies.dependents(plugin_id, depsInfo, platformJson, pluginInfoProvider);

    if(options.is_top_level && dependents && dependents.length > 0) {
        var msg = 'The plugin \'' + plugin_id + '\' is required by (' + dependents.join(', ') + ')';
        if(options.force) {
            events.emit('warn', msg + ' but forcing removal');
        } else {
            return Q.reject( new CordovaError(msg + ', skipping uninstallation. (try --force if trying to update)') );
        }
    }

    // Check how many dangling dependencies this plugin has.
    var deps = depsInfo.graph.getChain(plugin_id);

module.exports.prepare = function (cordovaProject, options) {
    var self = this;

    var platformJson = PlatformJson.load(this.locations.root, this.platform);
    var munger = new PlatformMunger(this.platform, this.locations.root, platformJson, new PluginInfoProvider());

    this._config = updateConfigFilesFrom(cordovaProject.projectConfig, munger, this.locations);

    // Update own www dir with project's www assets and plugins' assets and js-files
    return Q.when(updateWww(cordovaProject, this.locations))
    .then(function () {
        // update project according to config.xml changes.
        return updateProjectAccordingTo(self._config, self.locations);
    })
    .then(function () {
        updateIcons(cordovaProject, path.relative(cordovaProject.root, self.locations.res));
        updateSplashes(cordovaProject, path.relative(cordovaProject.root, self.locations.res));
    })
    .then(function () {
        events.emit('verbose', 'Prepared android project successfully');

function restoreMissingPluginsForPlatform(platform, projectRoot, options) {
    events.emit('verbose', 'Checking for any plugins added to the project that have not been installed in ' + platform + ' platform');

    // Flow:
    // 1. Compare .json file in /plugins ("old") and platforms/ ("new")
    // 2. If there is any differences - merge "old" one into "new"
    // 3. Reinstall plugins that are missing and was merged on previous step

    var oldPlatformJson = PlatformJson.load(path.join(projectRoot, 'plugins'), platform);
    var platformJson = PlatformJson.load(path.join(projectRoot, 'platforms', platform), platform);

    var missingPlugins = Object.keys(oldPlatformJson.root.installed_plugins)
        .concat(Object.keys(oldPlatformJson.root.dependent_plugins))
        .reduce(function (result, candidate) {
            if (!platformJson.isPluginInstalled(candidate))
                result.push({name: candidate,
                    // Note: isPluginInstalled is actually returns not a boolean,
                    // but object which corresponds to this particular plugin
                    variables: oldPlatformJson.isPluginInstalled(candidate)});

            return result;
        }, []);

    if (missingPlugins.length === 0) {
        events.emit('verbose', 'No differences found between plugins added to project and installed in ' +
            platform + ' platform. Continuing...');

function runInstall(actions, platform, project_dir, plugin_dir, plugins_dir, options) {
    project_dir = cordovaUtil.convertToRealPathSafe(project_dir);
    plugin_dir = cordovaUtil.convertToRealPathSafe(plugin_dir);
    plugins_dir = cordovaUtil.convertToRealPathSafe(plugins_dir);
    options = options || {};
    options.graph = options.graph || new dep_graph();
    options.pluginInfoProvider = options.pluginInfoProvider || new PluginInfoProvider();

    var pluginInfoProvider = options.pluginInfoProvider;
    var pluginInfo   = pluginInfoProvider.get(plugin_dir);
    var filtered_variables = {};
    var platformJson = PlatformJson.load(plugins_dir, platform);

    if (platformJson.isPluginInstalled(pluginInfo.id)) {
        if (options.is_top_level) {
            var msg = 'Plugin "' + pluginInfo.id + '" already installed on ' + platform + '.';
            if (platformJson.isPluginDependent(pluginInfo.id)) {
                msg += ' Making it top-level.';
                platformJson.makeTopLevel(pluginInfo.id).save();
            }
            events.emit('log', msg);
        } else {
            events.emit('log', 'Dependent plugin "' + pluginInfo.id + '" already installed on ' + platform + '.');
        }

        // CB-11022 return true always in this case since if the plugin is installed
        // we don't need to call prepare in any way
        return Q(true);

function installPluginsForNewPlatform(platform, projectRoot, opts) {
    // Install all currently installed plugins into this new platform.
    var plugins_dir = path.join(projectRoot, 'plugins');

    // Get a list of all currently installed plugins, ignoring those that have already been installed for this platform
    // during prepare (installed from config.xml).
    var platformJson = PlatformJson.load(plugins_dir, platform);
    var plugins = cordova_util.findPlugins(plugins_dir).filter(function (plugin) {
        return !platformJson.isPluginInstalled(plugin);
    });
    if (plugins.length === 0) {
        return Q();
    }

    var output = path.join(projectRoot, 'platforms', platform);
    var plugman = require('../plugman/plugman');
    var fetchMetadata = require('../plugman/util/metadata');

    // Install them serially.
    return plugins.reduce(function (soFar, plugin) {
        return soFar.then(function () {
            events.emit('verbose', 'Installing plugin "' + plugin + '" following successful platform add of ' + platform);
            plugin = path.basename(plugin);

module.exports.prepare = function (cordovaProject, options) {
    var self = this;

    var platformJson = PlatformJson.load(this.locations.root, this.platform);
    var munger = new PlatformMunger(this.platform, this.locations.root, platformJson, new PluginInfoProvider());

    this._config = updateConfigFilesFrom(cordovaProject.projectConfig, munger, this.locations);

    // Get the min SDK version from config.xml
    const minSdkVersion = this._config.getPreference('android-minSdkVersion', 'android');
    const maxSdkVersion = this._config.getPreference('android-maxSdkVersion', 'android');
    const targetSdkVersion = this._config.getPreference('android-targetSdkVersion', 'android');

    let gradlePropertiesUserConfig = {};
    if (minSdkVersion) gradlePropertiesUserConfig.cdvMinSdkVersion = minSdkVersion;
    if (maxSdkVersion) gradlePropertiesUserConfig.cdvMaxSdkVersion = maxSdkVersion;
    if (targetSdkVersion) gradlePropertiesUserConfig.cdvTargetSdkVersion = targetSdkVersion;

    let gradlePropertiesParser = new GradlePropertiesParser(this.locations.root);
    gradlePropertiesParser.configure(gradlePropertiesUserConfig);

function Api(platform, platformRootDir, events) {
    this.platform = PLATFORM;
    this.root = path.resolve(__dirname, '..');
    this.events = events || ConsoleLogger.get();
    // NOTE: trick to share one EventEmitter instance across all js code
    require('cordova-common').events = this.events;

    this._platformJson = PlatformJson.load(this.root, platform);
    this._pluginInfoProvider = new PluginInfoProvider();
    this._munger = new PlatformMunger(this.platform, this.root, this._platformJson, this._pluginInfoProvider);

    var self = this;

    this.locations = {
        root: self.root,
        www: path.join(self.root, 'assets/www'),
        platformWww: path.join(self.root, 'platform_www'),
        configXml: path.join(self.root, 'res/xml/config.xml'),
        defaultConfigXml: path.join(self.root, 'cordova/defaults.xml'),
        strings: path.join(self.root, 'res/values/strings.xml'),
        manifest: path.join(self.root, 'AndroidManifest.xml'),
        // NOTE: Due to platformApi spec we need to return relative paths here
        cordovaJs: 'bin/templates/project/assets/www/cordova.js',
        cordovaJsSrc: 'cordova-js-src'