Vulcan/packages/nova-lib/lib/callbacks.js
2016-12-13 11:32:23 +09:00

98 lines
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3.3 KiB
JavaScript

/**
* @summary Callback hooks provide an easy way to add extra steps to common operations.
* @namespace Callbacks
*/
export const Callbacks = {};
/**
* @summary Add a callback function to a hook
* @param {String} hook - The name of the hook
* @param {Function} callback - The callback function
*/
export const addCallback = function (hook, callback) {
// if callback array doesn't exist yet, initialize it
if (typeof Callbacks[hook] === "undefined") {
Callbacks[hook] = [];
}
Callbacks[hook].push(callback);
};
/**
* @summary Remove a callback from a hook
* @param {string} hook - The name of the hook
* @param {string} functionName - The name of the function to remove
*/
export const removeCallback = function (hookName, callbackName) {
Callbacks[hookName] = _.reject(Callbacks[hookName], function (callback) {
return callback.name === callbackName;
});
};
/**
* @summary Successively run all of a hook's callbacks on an item
* @param {String} hook - First argument: the name of the hook
* @param {Object} item - Second argument: the post, comment, modifier, etc. on which to run the callbacks
* @param {Any} args - Other arguments will be passed to each successive iteration
* @returns {Object} Returns the item after it's been through all the callbacks for this hook
*/
export const runCallbacks = function () {
// the first argument is the name of the hook
const hook = arguments[0];
// the second argument is the item on which to iterate
const item = arguments[1];
// successive arguments are passed to each iteration
const args = Array.prototype.slice.call(arguments).slice(2);
const callbacks = Callbacks[hook];
if (typeof callbacks !== "undefined" && !!callbacks.length) { // if the hook exists, and contains callbacks to run
return callbacks.reduce(function(result, callback) {
// console.log(callback.name);
// return callback(result, constant);
const newArguments = [result].concat(args);
return callback.apply(this, newArguments);
// uncomment for debugging
// try {
// return callback(result, constant);
// } catch (error) {
// console.log(`// error at callback [${callback.name}] in hook [${hook}]`)
// throw error;
// }
}, item);
} else { // else, just return the item unchanged
return item;
}
};
/**
* @summary Successively run all of a hook's callbacks on an item, in async mode (only works on server)
* @param {String} hook - First argument: the name of the hook
* @param {Any} args - Other arguments will be passed to each successive iteration
*/
export const runCallbacksAsync = function () {
// the first argument is the name of the hook
var hook = arguments[0];
// successive arguments are passed to each iteration
var args = Array.prototype.slice.call(arguments).slice(1);
var callbacks = Callbacks[hook];
if (Meteor.isServer && typeof callbacks !== "undefined" && !!callbacks.length) {
// use defer to avoid holding up client
Meteor.defer(function () {
// run all post submit server callbacks on post object successively
callbacks.forEach(function(callback) {
// console.log("// "+hook+": running callback ["+callback.name+"] at "+moment().format("hh:mm:ss"))
callback.apply(this, args);
});
});
}
};