1.0.0 • Published 9 years ago
dependencies-online v1.0.0
Dependencies Online
Simple asynchronous dependency resolver
Overview
This is a dependency graph for loading things as early as possible, once anything they depend on is loaded. The dependency graph does not know anything about how loading works--it can be used to resolve any kind of dependencies. To use, npm install dependencies-online
and then `require('dependencies-online').
API
DependencyGraph
Nodes in the graph are strings with the name
of the module
new DependencyGraph(options)
- create a new dependency graph. ifoptions.checkCircular
is true (the default), then trying to add a circular dependency will throw an error that includes the cycle in the message.add(name, dependencies, resolver)
- add a node in the graph.dependencies
is an array of nodes this node depends on to have resolved before loading. ifresolver
is provided, it is called when the module should load automatically.resolver
can return the module or a promise.add
returns a promise indicating whether the dependencies have loaded successfully.has(name)
- check if the node exists in the graph.isResolved(name)
- returns a promise indicating whether the dependency was resolved successfully or unsuccessfullyresolve(name, success, details)
- mark a dependency as resolved/loaded. Ifsuccess
is true, marks the dependency as resolved.details
can be used to store i.e. the loaded module. Ifsucesss
is false, indicates that the module was not loaded and never will be, causing everything that depends on it to likewise fail.details
can include any error message.
Examples
var DependencyGraph = require('dependencies-online')
var graph = new DependencyGraph()
graph.add('a')
graph.add('b', ['a']).then(function() {
console.log("resolving module B immediately");
graph.resolve('b');
return 'module b';
});
graph.add('c', ['b'], function() {
return new Promise(function(resolve, reject) {
console.log("resolving module C immediately in a 'resolver' promise");
resolve('module c');
});
});
graph.add('d');
graph.has('a'); // True
graph.has('zzz'); // False
graph.isResolved('c'); // False
graph.resolve('a', true, 'module a');
// Prints: resolving module B immediately
// resolving module C immediately in a 'resolver' promise
graph.isResolved('a'); // True promise
graph.isResolved('b'); // True promise
graph.isResolved('c'); // True promise
graph.isResolved('d'); // Unresolved promise
1.0.0
9 years ago