React mixin with script loader

LoginForm

import React from 'react/addons';
import ReactMixin from 'react-mixin';
import ReactScriptLoaderMixin from 'react-script-loader';

export default class LoginForm extends React.Component {
	constructor() {
		super();
		this.state = {
			user: '',
			password: '',
			scriptLoading: true,
            scriptLoadError: false,
		};
	}

	// this function tells ReactScriptLoaderMixin where to load the script from
    getScriptURL() {
        return 'https://www.google.com/recaptcha/api.js';
    }

    // ReactScriptLoaderMixin calls this function when the script has loaded
    // successfully.
    onScriptLoaded() {
    	console.log('ReactScriptLoaderMixin: onScriptLoaded');
        this.setState({scriptLoading: false});
    }

    // ReactScriptLoaderMixin calls this function when the script has failed to load.
    onScriptError() {
    	console.log('ReactScriptLoaderMixin: onScriptLoaded');
        this.setState({scriptLoading: false, scriptLoadError: true});
    }

    onScriptTagCreated() {
    	console.log('ReactScriptLoaderMixin: onScriptTagCreated');
    }

	login(e) {
		e.preventDefault();
		alert('will login');
	}

	render() {
		var message = "react script loader: "
		if (this.state.scriptLoading) {
            message += 'loading script...';
        } else if (this.state.scriptLoadError) {
            message += 'loading failed';
        } else {
            message += 'loading succeeded';
        }
        console.log(message);

		return(
			<form role="form" id="login-form" className="login-form">
	            <div className="row">
	              <div className="form-group col-md-12">
	                <label className="form-label">Username</label>
	                <div className="controls">
	                  <div className="input-with-icon right">
	                    <i></i>
	                    <input id="txtusername" type="text" name="txtusername" className="form-control"
	                      valueLink={this.linkState('user')} />
	                  </div>
	                </div>
	              </div>
	            </div>
	            <div className="row">
	              <div className="form-group col-md-12">
	                <label className="form-label">Password</label><span className="help"></span>
	                <div className="controls">
	                  <div className="input-with-icon right"><i></i>
	                    <input id="txtpassword" type="password" name="txtpassword" className="form-control"
	                      valueLink={this.linkState('password')} />
	                  </div>
	                </div>
	              </div>
	            </div>
	            <div className="row">
	              <div className="form-group col-md-12">
	                <label className="form-label">Captcha</label><span className="help"></span>
	                <div className="controls">
	                  <div className="input-with-icon right"><i></i>
	                    <div className="g-recaptcha" data-sitekey="6Lc4zggTAAAAAIQhg0kFlMA0qpy4PLyulMaPt-8-"></div>
	                  </div>
	                </div>
	              </div>
	            </div>
	            <div className="row">
	              <div className="control-group col-md-12">
	                <div className="checkbox checkbox check-success"><a href="#">Trouble login in?</a>
	                  <br/><br/>
	                  <input id="checkbox1" type="checkbox" value="1" />
	                  <label htmlFor="checkbox1">Keep me reminded</label>
	                </div>
	              </div>
	            </div>
	            <div className="row">
	              <div className="col-md-12">
	                <button type="submit" className="btn btn-primary btn-cons pull-right" 
	                  onClick={this.login.bind(this)}>Login</button>
	              </div>
	            </div>
	        </form>
		);
	}
}

ReactMixin(LoginForm.prototype, React.addons.LinkedStateMixin);
ReactMixin(LoginForm.prototype, ReactScriptLoaderMixin);

ReactScriptLoaderMixin

// A dictionary mapping script URLs to a dictionary mapping
// component key to component for all components that are waiting
// for the script to load.
var scriptObservers = {};

// A dictionary mapping script URL to a boolean value indicating if the script
// has already been loaded.
var loadedScripts = {};

// A dictionary mapping script URL to a boolean value indicating if the script
// has failed to load.
var erroredScripts = {};

// A counter used to generate a unique id for each component that uses
// ScriptLoaderMixin.
var idCount = 0;

var ReactScriptLoader = {
	componentDidMount: function(key, component, scriptURL) {
		if (typeof component.onScriptLoaded !== 'function') {
			throw new Error('ScriptLoader: Component class must implement onScriptLoaded()');
		}
		if (typeof component.onScriptError !== 'function') {
			throw new Error('ScriptLoader: Component class must implement onScriptError()');
		}
		if (loadedScripts[scriptURL]) {
			component.onScriptLoaded();
			return;
		}
		if (erroredScripts[scriptURL]) {
			component.onScriptError();
			return;
		}

		// If the script is loading, add the component to the script's observers
		// and return. Otherwise, initialize the script's observers with the component
		// and start loading the script.
		if (scriptObservers[scriptURL]) {
	    	console.log('ReactScriptLoaderMixin: add component to scriptObservers');
			scriptObservers[scriptURL][key] = component;
			return;
		}

		var observers = {};
		observers[key] = component;
		scriptObservers[scriptURL] = observers;

    	console.log('ReactScriptLoaderMixin: creating script tag');
		var script = document.createElement('script');

		if (typeof component.onScriptTagCreated === 'function') {
			component.onScriptTagCreated(script);
		}

		script.src = scriptURL;
		script.async = 1;

		var callObserverFuncAndRemoveObserver = function(func) {
			var observers = scriptObservers[scriptURL];
			for (var key in observers) {
				observer = observers[key];
				var removeObserver = func(observer);
				if (removeObserver) {
					delete scriptObservers[scriptURL][key];
				}
			}
			//delete scriptObservers[scriptURL];
		}
		script.onload = function() {
			loadedScripts[scriptURL] = true;
			callObserverFuncAndRemoveObserver(function(observer) {
				if (observer.deferOnScriptLoaded && observer.deferOnScriptLoaded()) {
					return false;
				}
				observer.onScriptLoaded();
				return true;
			});
		};
		script.onerror = function(event) {
			erroredScripts[scriptURL] = true;
			callObserverFuncAndRemoveObserver(function(observer) {
				observer.onScriptError();
				return true;
			});
		};
		// (old) MSIE browsers may call 'onreadystatechange' instead of 'onload'
		script.onreadystatechange = function() {
  			if (this.readyState == 'loaded') {
    			// wait for other events, then call onload if default onload hadn't been called
    			window.setTimeout(function() {
      				if (loadedScripts[scriptURL] !== true) script.onload();
    			}, 0);
  			}
		};
		
		console.log('append script', script);
		document.body.appendChild(script);
	},
	componentWillUnmount: function(key, scriptURL) {
		// If the component is waiting for the script to load, remove the
		// component from the script's observers before unmounting the component.
		var observers = scriptObservers[scriptURL];
		if (observers) {
			delete observers[key];
		}
	},
	triggerOnScriptLoaded: function(scriptURL) {
		if (!loadedScripts[scriptURL]) {
			throw new Error('Error: only call this function after the script has in fact loaded.');
		}
		var observers = scriptObservers[scriptURL];
		for (var key in observers) {
			var observer = observers[key];
			observer.onScriptLoaded();
		}
		delete scriptObservers[scriptURL];
	}
};

var ReactScriptLoaderMixin = {
	componentDidMount: function() {
		if (typeof this.getScriptURL !== 'function') {
			throw new Error("ScriptLoaderMixin: Component class must implement getScriptURL().")
		}
    	console.log('ReactScriptLoaderMixin: componentDidMount');
        if (this.getScriptURL() instanceof Array) {
    		console.log('ReactScriptLoaderMixin: load array of scripts', this.getScriptURL());
            for (var i in this.getScriptURL()) {
		        ReactScriptLoader.componentDidMount(this.__getScriptLoaderID(), this, this.getScriptURL()[i]);
            }
        } else {
		    ReactScriptLoader.componentDidMount(this.__getScriptLoaderID(), this, this.getScriptURL());
        }
	},
	componentWillUnmount: function() {
    	console.log('ReactScriptLoaderMixin: componentWillUnmount');
		if (this.getScriptURL() instanceof Array) {
	        for (var i in this.getScriptURL()) {
		        ReactScriptLoader.componentWillUnmount(this.__getScriptLoaderID(), this, this.getScriptURL()[i]);
		    }
        } else {
		    ReactScriptLoader.componentWillUnmount(this.__getScriptLoaderID(), this.getScriptURL());
        }
	},
	__getScriptLoaderID: function() {
		if (typeof this.__reactScriptLoaderID === 'undefined') {
			this.__reactScriptLoaderID = 'id' + idCount++;
		}

		return this.__reactScriptLoaderID;
	},
};

exports.ReactScriptLoaderMixin = ReactScriptLoaderMixin;
exports.ReactScriptLoader = ReactScriptLoader;