Last active
April 30, 2018 01:21
-
-
Save jpillora/5667454 to your computer and use it in GitHub Desktop.
Micro JavaScript Dependancy Injection.Written in CoffeeScript / JS.This is *approximately* how AngularJS works.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
# Micro JavaScript Dependancy Injection | |
define = (name, val) -> | |
#init modules map if missing | |
define.mods = define.mods or {} | |
#store 'name' | |
define.mods[name] = val | |
inject = (fn) -> | |
#regex match on function.toString() | |
m = fn.toString().match /function\s(\w+)?\((.*)\)/ | |
throw "Function parse failed" unless m | |
#prepare arguments | |
args = [] | |
#loop through function parameter names | |
for name in m[2].split(", ") | |
continue unless name | |
#look for module with 'name' | |
m = define.mods[name] | |
throw "Missing '#{name}' module" unless m | |
#add to arguments | |
args.push m | |
#call function with arguments | |
fn.apply this, args | |
#example usage | |
define 'a', 42 | |
define 'b', 21 | |
define 'c', 7 | |
inject -> print "no-args" #no-args | |
inject (b) -> print b #21 | |
inject (a,b,c) -> print a+b-c #56 |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// Micro JavaScript Dependancy Injection | |
var define = function(name, val) { | |
//init modules map if missing | |
define.mods = define.mods || {}; | |
//store 'name' | |
return define.mods[name] = val; | |
}; | |
var inject = function(fn) { | |
var args, m, name, i, params; | |
//regex match on function.toString() | |
m = fn.toString().match(/function\s(\w+)?\((.*)\)/); | |
if (!m) throw "Function parse failed"; | |
//prepare arguments | |
args = []; | |
params = m[2].split(", "); | |
//loop through function parameter names | |
for (i = 0; i < params.length; i++) { | |
name = params[i]; | |
if (!name)continue; | |
//look for module with 'name' | |
m = define.mods[name]; | |
if (!m) throw "Missing '" + name + "' module"; | |
//add to arguments | |
args.push(m); | |
} | |
//call function with arguments | |
return fn.apply(this, args); | |
}; | |
//example usage | |
define('a', 42); | |
define('b', 21); | |
define('c', 7); | |
inject(function() { | |
return print("no-args"); | |
}); | |
inject(function(b) { | |
return print(b); //21 | |
}); | |
inject(function(a, b, c) { | |
return print(a + b - c); //56 | |
}); |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
As Function.toString() is defined lexically (and so statically), I think it would be nice also to have such thing implemented as a source code transform.