lib/output/callHook.js


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var Promise = require('../utils/promise');
var Api = require('../api');

function defaultGetArgument() {
    return undefined;
}

function defaultHandleResult(output, result) {
    return output;
}

/**
    Call a "global" hook for an output

    @param {String} name
    @param {Function(Output) -> Mixed} getArgument
    @param {Function(Output, result) -> Output} handleResult
    @param {Output} output
    @return {Promise<Output>}
*/
function callHook(name, getArgument, handleResult, output) {
    getArgument = getArgument || defaultGetArgument;
    handleResult = handleResult || defaultHandleResult;

    var logger = output.getLogger();
    var plugins = output.getPlugins();

    logger.debug.ln('calling hook "' + name + '"');

    // Create the JS context for plugins
    var context = Api.encodeGlobal(output);

    // Get the arguments
    return Promise(getArgument(output))

    // Call the hooks in serie
    .then(function(arg) {
        return Promise.reduce(plugins, function(prev, plugin) {
            var hook = plugin.getHook(name);
            if (!hook) {
                return prev;
            }

            return hook.call(context, prev);
        }, arg);
    })

    // Handle final result
    .then(function(result) {
        output = Api.decodeGlobal(output, context);
        return handleResult(output, result);
    });
}

module.exports = callHook;