JavaScript Design Pattern Learning factory_javascript Skills

Copy Code code as follows:

/* Displaymodule interface. */
var displaymodule = new Interface (' Displaymodule ', [' Append ', ' remove ', ' clear ']);
/* Listdisplay class. */
Implements the factory through the interface, this is the list way to display the RSS
var listdisplay = function (ID, parent) {//Implements Displaymodule
This.list = document.createelement (' ul ');
This.list.id = ID;
Parent.appendchild (this.list);
};
Listdisplay.prototype = {
Append:function (text) {
var newel = document.createelement (' li ');
This.list.appendChild (NEWEL);
newel.innerhtml = text;
return newel;
},
Remove:function (EL) {
This.list.removeChild (EL);
},
Clear:function () {
This.list.innerHTML = ';
}
};
/* Configuration object. */
var conf = {
ID: ' Cnn-top-stories ',
Feedurl: ' Http://rss.cnn.com/rss/cnn_topstories.rss ',
UPDATEINTERVAL:60,//in seconds.
Parent: $ (' feed-readers ')
};
/* Feedreader class. */
var feedreader = function (display, Xhrhandler, conf) {
This.display = display;
This.xhrhandler = Xhrhandler;
this.conf = conf;
This.startupdates ();
};
Feedreader.prototype = {
Fetchfeed:function () {
var that = this;
var callback = {
Success:function (text, XML) {that.parsefeed (text, XML);},
Failure:function (status) {That.showerror (status);}
};
This.xhrHandler.request (' Get ', ' feedproxy.php?feed= ' + THIS.CONF.FEEDURL,
callback);
},
Parsefeed:function (ResponseText, Responsexml) {
This.display.clear ();
var items = responsexml.getelementsbytagname (' item ');
for (var i = 0, len = items.length i < len; i++) {
var title = Items[i].getelementsbytagname (' title ') [0];
var link = items[i].getelementsbytagname (' link ') [0];
This.display.append (' <a href= ' + link.firstChild.data + ' "> ' +
Title.firstChild.data + ' </a> ');
}
},
Showerror:function (StatusCode) {
This.display.clear ();
This.display.append (' Error fetching feed. ');
},
Stopupdates:function () {
Clearinterval (This.interval);
},
Startupdates:function () {
This.fetchfeed ();
var that = this;
This.interval = setinterval (function () {that.fetchfeed ();},
This.conf.updateInterval * 1000);
}
};
/* Feedmanager namespace. */
Factory Manager, where you can select specific display based on the parameters that are passed in
var Feedmanager = {
Createfeedreader:function (conf) {
var displaymodule = new Listdisplay (conf.id + '-display ', conf.parent);
Interface.ensureimplements (Displaymodule, displaymodule);
var xhrhandler = Xhrmanager.createxhrhandler ();
Interface.ensureimplements (Xhrhandler, Ajaxhandler);
Return to New Feedreader (Displaymodule, Xhrhandler, conf);
}
};
=====================================================
Another example of a bicycle factory:
var bicycleshop = function () {};
Bicycleshop.prototype = {
Sellbicycle:function (model) {
var bicycle = this.createbicycle (model);
Bicycle.assemble ();
Bicycle.wash ();
return bicycle;
},
Createbicycle:function (model) {
throw new Error (' unsupported operation on an abstract class. ');
}
};
/* Acmebicycleshop class. */
var acmebicycleshop = function () {};
Extend (Acmebicycleshop, bicycleshop);
AcmeBicycleShop.prototype.createBicycle = function (model) {
var bicycle;
Switch (model) {
Case ' The Speedster ':
Bicycle = new Acmespeedster ();
Break
Case ' The Lowrider ':
Bicycle = new Acmelowrider ();
Break
Case ' The Flatlander ':
Bicycle = new Acmeflatlander ();
Break
Case ' The Comfort Cruiser ':
Default
Bicycle = new Acmecomfortcruiser ();
}
Interface.ensureimplements (bicycle, bicycle);
return bicycle;
};
/* Generalproductsbicycleshop class. */
var generalproductsbicycleshop = function () {};
Extend (Generalproductsbicycleshop, bicycleshop);
GeneralProductsBicycleShop.prototype.createBicycle = function (model) {
var bicycle;
Switch (model) {
Case ' The Speedster ':
Bicycle = new Generalproductsspeedster ();
Break
Case ' The Lowrider ':
Bicycle = new Generalproductslowrider ();
Break
Case ' The Flatlander ':
Bicycle = new Generalproductsflatlander ();
Break
Case ' The Comfort Cruiser ':
Default
Bicycle = new Generalproductscomfortcruiser ();
}
Interface.ensureimplements (bicycle, bicycle);
return bicycle;
};

/* Usage. */

Copy Code code as follows:

var alecscruisers = new Acmebicycleshop ();
var yournewbike = alecscruisers.sellbicycle (' the Lowrider ');
var bobscruisers = new Generalproductsbicycleshop ();
var yoursecondnewbike = bobscruisers.sellbicycle (' the Lowrider ');