I need to make changes to an existing project that uses iFrames to dynamically load external html files. However, the html files are part of the same project, not external sites. If I'm not mistaken, iFrames are considered a terrible way of loading html content unless they are used to actually display external sites.
I have looked into web components but apparently, browser support is still spotty and unfortunately, I need to support IE9.
I know that the JQuery load() method can accomplish this but in my online research, that doesn't often come up as a proper way of loading external html in general and a proper replacement for iFrames in particular.
Is there a reason why JQuery shouldn't be used here and are there better and established ways of doing this? For example, I once saw a framework that dynamically built the interface out of separate "partials" but I don't remember which framework that was.
It depends on the HTML -
If it's built like a full page - then iFrames are actually a decent solution - Also, iframes with the same origin let you have full control over the content from the parent, while still protecting CSS and JS variables which is pretty convenient.
If not - jQuery.load() will do the trick, you can also do it manually ofc, but if you already have jQuery in your project, just use it.
The load() function is almost always the best way to go, if you are encountering a specific issue using that function maybe you can share it?
I just did a proof of concept/demo for a web app idea I had but that idea needs to be embedded on pages to work properly.
I'm now done with the development of the demo but now I have to tweak it so it works within a tag on any websites.
The question here is:
How do I achieve this without breaking up the main website's stylesheets and javascript?
It's a node.js/socket.io/angularjs/bootstrap based app for your information.
I basically have a small HTML file, a few css and js files and that's all. Any idea or suggestions?
If all you have is a script tag, and you want to inject UI/HTML/etc. into the host page, that means that an iframe approach may not be what you want (although you could possibly do a hybrid approach). So, there are a number of things that you'd need to do.
For one, I'd suggest you look into the general concept of a bookmarklet. While it's not exactly what you want, it's very similar. The problems of creating a bookmarklet will be very similar:
You'll need to isolate your JavaScript dependencies. For example, you can't load a version of a library that breaks the host page. jQuery for example, can be loaded without it taking over the $ symbol globally. But, not all libraries support that.
Any styles you use would also need to be carefully managed so as to not cause issues on the host page. You can load styles dynamically, but loading something like Bootstrap is likely going to cause problems on most pages that aren't using the exact same version you need.
You'll want your core Javascript file to load quickly and do as much async work as possible as to not affect the overall page load time (unless your functionality is necessary). You'll want to review content like this from Steve Souders.
You could load your UI via a web service or you could construct it locally.
If you don't want to use JSONP style requests, you'll need to investigate enabling CORS.
You could use an iframe and PostMessage to show some UI without needing to do complex wrapping/remapping of the various application dependencies that you have. PostMessage would allow you to send messages to tell the listening iFrame "what to do" at any given point, while the code that is running in the host page could move/manipulate the iframe into position. A number of popular embedded APIs have used this technique over the years. I think DropBox was using it for example.
I am currently writing whats going to be a very, very large single page web/javascript application.
Technologies I am using are ASP.NET MVC4, jquery, knockout.js and amplify.js.
The problem I am having is that most if not all of the single page application examples are for smaller applications where having all of the script templates (be it jquery, handlbars, etc...) are all in the same file along with the rest of the html code. This is fine for smaller apps but the application I am building is an entire maintenance logistics application with many, many, many screens.
The approach I took so far is I have an outer shell (my main index.cshtml file) and I am using jquery's load() method to load or rather inject the particular file I need when a user makes a certain selection.
example:
function handleLoginClick(){
App.mainContentContainer.delegate('#btnLogin', 'click', function() {
App.loadModule('Home/ProductionControlMenu', App.MainMenuView.render());
});
}
here's the code for the App.loadModule function:
App.loadModule = function(path, callback){
App.mainContentContainer.load(App.siteRoot + path, callback);
};
All was going well until I needed to actually start interacting with the various form elements on the newly loaded screen. jquery can't seem to get a handle on them directly. I can't use .live() or .delegate() because they aren't events, they are textboxes and buttons and sometimes I need to change their css classes.
They only way I found is to get a handle on an element from the outer shell (something that wasn't loaded via .load() ) and use jquery's .find() method like so:
App.mainContentContainer.find('#btnLogin').addClass('disabled');
clearly I don't want to have to do something like this everytime I need to interact with or even retrieve values from a form element.
Does anybody have any ideas as to how I can create a maintainable very large single page application with potentially hundreds of .html files without having to have all that html code located in a single file and still get around this .load() issue I am having?
Any thoughts would be greatly appreciated. :-)
V/R
Chris
UPDATE
I thought I'd post an update and as to how things went and what worked. After much research I decided to go with Google's AngularJS Javascript framework. It simplified the ordeal exponentially and I would definitely, definitely advise all who are looking into making a large SPA to give it a look.
Links:
Main Site
http://angularjs.org/
Awesome free short videos on Angular:
http://www.egghead.io/
This is actually a very complicated question as it really gets down to the design of your architecture.
For large-scale single-page applications, it's best to use some sort of front-end MV* style framework such as backbone.js, which ties in to jQuery quite usefully. You should also think about using some sort of dependency management framework such as require.js in order to load your scripts and dependencies asynchronously, and even better -- use the AMD pattern in your application design to make your architecture modular and easier to manage.
As far as how this relates to your MVC4 project, you have some options:
Do you want to use MVC as a "service layer" of sorts, that simply returns JSON objects, allowing your front-end to do the markup/template creation (think handlebars.js), or
Do you want your MVC project to return partial views (HTML) as a response, where you leverage the Razor templating system and simply use the front end to display what comes back from the server?
Either way, you will have to devise a way to handle front-end events and navigation (backbone provides both of these things when coupled with jQuery). Even more complicated is the pattern you choose to notify one view of another view's activities (there are many ways to do this) -- a publish/subscribe pattern for example.
I hope I have helped a bit, I know I'm not fully answering the question, but the answer could get really long!
Lots of things are wrong with your approach. What I'd recommend is to watch some presentations on how people build Single Page Applications and what tooling is mostly used.
This seems like something reasonable: http://singlepageappbook.com/
You will at least want
some kind of modules system (I recommend AMD – http://requirejs.org)
an MV* framework (Backbone, Ember.js etc.)
DOM/AJAX Framework (jQuery, Mootools etc.). Some frameworks offer this and all of the above (Dojo, YUI, Sencha)
build solution (to have different environment in development / production)
Couple of good links:
http://nerds.airbnb.com/slides-and-video-from-spike-brehms-tech-talk
http://video.copenhagenjs.dk/video/3413395/simon-hjberg-swipely-building
http://backstage.soundcloud.com/2012/06/building-the-next-soundcloud/
http://www.youtube.com/watch?v=vXjVFPosQHw
If you don't need a complicated truly SOFEA Single Page App then I recommend you go the PJAX route.
Then you just write your app as a normal web 1.0 app with the performance benefits of a single page load. I urge you to consider this an option as it allows you to do most of your validation work server side.
The idea is very simple on every response your sending the whole page back minus the header and footer (which contains the javascript and css includes). DOM rendering time is incredible fast these days... whats not is a full page reload, So don't worry about the size of the HTML your returning back.
Also the "PJAX way" is much easier to cache, Google SEO friendly and is in fact what the new Basecamp does.
Note: Wanted this to be a comment not an answer but don't have enough exp to post comments ;(
[any corrections by community members welcome!]
Important points to consider for single page apps:
Lazy loading is vital as you don't want hundreds of js files loaded straight away as user first loads the page (very slow load time).
Good File organisation,- helps making changes easier, reduces complexity a bit and promotes reusable components. Makes testing of components easier.
Testing,- Since single page apps have a lot of javascript going on under the hood you would need a test framework for automatically testing components. This testing is on top of the tests you would use to confirm if certain user controls are rendered etc as you wouldn't want a viewless component making an ajax call to server when it shouldn't etc.
+1 for gryzzly's point about using a framework.
Sencha have a nice MVC like framework for their ExtJs product. They have data stores, ajax, lazy loading, class hierarchies and a lot more all bundled into the package. They have a good api page also to lookup object properties and methods (handy since there doesn't seem to be any intellisense for javascript :/ ). Their api page is; as far as I know, an example of a single page app. I know much of the stuff ExtJs does you can find an open source alternative but I like that it's just the one library and I don't have to download a couple of different frameworks to do various operations. [note: I have no affiliation to Sencha except for being a customer of theirs and like their stuff.]
Conclusion:
I'd say it would be quite difficult to manage a large single page app without using some client side framework; whether open source or not, and without using some architectural pattern like a client side MVC.
Single page apps I think are more complicated so your team would need to be quite handy at understanding the concept of a single page app and how to implement it. If you pull it off the site will be amazing in terms of user experience.
I would recommend to use Sammy.js and split various viewmodels in knockout to a separate url. And if you're using asp.net mvc 4, use partial views (user controls) so that you put all code in one file. And name all and split all js-code in a meaningful way, filename and namespace in js. That will help a lot in maintainability and your own sanity in the long run.
And use common sense!
The way I did it was to include javascript code related to the template along with the template itself. And then load the whole template+script thing using ajax. If you want to try this be warned that most browsers don't execute <script> tags injected into the page. Especially if done using innerHTML. As such you should eval the script tags yourself (alternatively you can use document.createElement to inject the script but this does not offer any additional advantages compared to eval since the browser will blindly execute the script anyway).
In my case, to make it easier to grab the html and script portions of the template I store my templates in XML files instead of plain old HTML. That way I can simply use .responseXML of the ajax request to parse the template. My template has the following basic structure:
<template options...>
<title>Optional</title>
<html><![CDATA[
Template body
]]></html>
<init><![CDATA[
// code that only needs to execute once
]]></init>
<script><![CDATA[
// code that needs to run every time
// the template loads
]]></script>
</template>
You also need to remember to configure your server to reply with the correct content type for you templates. Otherwise resultXML won't work. This is not the only way to implement this system of course. You could simply save your templates as HTML and then parse that HTML to extract scripts to execute.
The main bulk of your code, the functions, constructors, objects etc. can be included in a js file. The template script only need to call those functions to tell the rest of the page how to work with the template.
If you further separate your data from your template and only populate the template with data on the page or make a separate ajax request for JSON data then you can configure your server to make the browser cache your templates. This is especially useful for often used templates (such as templates for dialog boxes). This allows the browser to download the template only once and use the cached version the next time you call the template.
Anyway, that's how I did it last time. It scaled well enough to serve facebook users (the web app was a facebook app). Just sharing my experience. Hope it helps.
I've written a few huge single page application using Dojo Toolkit. I'm pretty sure whatever JavaScript framework you choose will probably work for you. I use Dojo because it provides me with features that makes huge single page application development easier to manage.
You can use Dojo's widget system to help you define all your screens and forms as widgets and then when you need them you can just instantiate and insert them wherever you need it. When ever you want to get rid of it, you can simply call destroy or destroyRecursive on that particular widget and its gone. Dojo's widget system also help you separate your HTML from your JavaScript, but still keep it together so that they are not located all over the place.
I've include a simple widget definition for a Login form.
This is the HTML template.
/* mine/forms/Login.html */
<div>
${form_name}
<label>Username</label>
<input data-dojo-type="dijit.form.TextBox"
data-dojo-attach-point="_usrfld" />
<br />
<label>Password</label>
<input data-dojo-type="dijit.form.TextBox"
data-dojo-props="type: 'password'"
data-dojo-attach-point="_pwdfld" />
<br />
<input data-dojo-type="dijit.form.Button"
data-dojo-props="label: 'Login'"
data-dojo-attach-event="onClick:_handleLogin" />
</div>
This is the JavaScript portion for the widget.
/* mine/forms/Login.js */
define([
"dojo/_base/declare",
"dijit/_Widget",
"dijit/_Templated",
"dijit/_WidgetsInTemplateMixin",
"dijit/form/Button",
"dijit/form/TextBox",
"dojo/text!./Login.html"
], function(
declare,
_Widget,
_Templated,
_WidgetsInTemplateMixin,
Button,
TextBox,
template
) {
return declare("mine.forms.Login", [_Widget, _Templated, _WidgetsInTemplateMixin], {
// assign the template
templateString: template,
// signal that we will have widgets within our template and the parser should
// locate them and instantiate them
widgetsInTemplate: true,
form_name: "My Login Form",
// place holders that will be referencing the corresponding widgets
// that I have placed a data-dojo-attach-point on
_usrfld: null,
_pwdfld: null,
_lgbtn: null,
// a call back function that will be trigger when the Login button is clicked
_handleLogin: function() {
var usr = this._usrfld.get('value');
var pwd = this._pwdfld.get('value');
// now you have the username & password
// you can use it to login
}
});
});
There are a few benefits that the widget system provides:
The HTML template will be loaded for you when needed
You can have widgets within widgets. Dojo takes care of instantiating and even destroying those widgets for you
You can use dojo's simple template language to help with inserting strings. The example above uses ${form_name}. If you want to use a more sophisticate facility dojo also supports a Django similar syntax templating language. This will allow you to use most of the tags available with Django like for, if-then-else, etc.
data-dojo-attach-point is very helpful. If you use this, you will never need to assign id to a DOM element anymore. You will not need to locate the element in your HTML DOM tree. The variable you name in data-dojo-attach-point will be auto assign to reference the widget or DOM element you have defined in your template. The example above uses the _usrfld, _pwdfld, and _lgbtn.
data-dojo-attach-event is also very helpful. If you use this, you will not have to manully add an event hook to the button, Dojo's widget system will hook it for you and will also clear the hook when your widget is destroyed.
If you use Dojo's build system, which is a system that takes all your JavaScript codes and compresses them, Dojo will replace your template with the actual HTML so that when you load your widget in production mode, Dojo doesn't have to make another AJAX request to grab your template.
These are just some of the features I use daily when I develop my projects. Hopefully it will provide you with some insight that you can use to make your decision when choosing the proper JavaScript framework for your project. As a side note, I'm not advocating Dojo or anything, just wanted to share what works for me.
To handle large size single page application it's recommended to break the individual module into different apps.
example : apps like search page app and result page app.
I am tinkering around with jQuery and am finding it very useful and almost exciting.
As of now, I am referencing the jQuery script via Google's CDN and I store plugins I use locally in a static/scripts directory.
Naturally, each page has its own individual implementation of components that are required for the features it currently offers. I.E. the main page has the Twitter plugin whereas the login page has form validation logic and password strength metering. However, certain components (navigation bar) for example use the same script across multiple pages.
Admittedly so, I am not a fan of putting javascript code in the header of a page, but I rather prefer to have it in an external file (for caching, re-usability, and optimization purposes).
My question is, what is the preferred route for organizing the external files. I wanted to try and keep it to one javascript file for the entire site to reduce IO requests. However, I am not sure how to implement document ready functions on a conditional per page bases.
$(document).ready(function () { ... }
Is there some way to reference a page by some method (preferably id based and not a url conditional).
Thank you in advance for your time!
You should try REQUIRE JS.
This will allow you to load only those plugins the pages where you need them, and unload them again if they are not needed anymore.
Then again, it might be overkill. It really depends on the size of your project.
Paul Irish:
http://paulirish.com/2009/markup-based-unobtrusive-comprehensive-dom-ready-execution/
This will allow you to block your scripts by body class/ID and execute them automatically.
First you might want to use YUI Compressor or some other JS compressing tool. Then perhaps creating a resource file (resx) for your JavaScript is the way to go. Then just reference the resource within your code. This is the approach Telerik took for their RadControl ASP.NET AJAX control framework.
I am a javascript newbie. I am trying to write a requirements document, and need some help describing what I am looking for. We want our application to generate a javascript snippet like this:
<script src="http://www.jotform.com/jsform/10511502633"></script>
This will load a web form.
So my question is:
- How does a single script load an entire web form? Is this a JSON?
- What is this called? Is this a cross browser javascript?
- Can anyone point me in the direction of learning more about what this is?
Thank you for your help!
The javascript file is just hosted on an external site. It appears to be dynamically generated, so feel free to use some fancy words ;) But basically, you just include it here, as if it was on your own site.
You could say "The application will generate the required script-tags to include dynamically generated javascript file from an external, third-party site".
Offcourse you need to take special cautions for cases when the include won't work, because the other site is not reachable (site is down, DNS does not work, file is moved on other webserver, your application is on an intranet/behind a proxy/firewall...). Why can't you copy their file and mirror it locally? Or use a reliable Content Delivery Network, like Google or Amazon.
There are many names for this type of inclusion. The most common being widget.
What does it actually do:
take an id of some sort as parameter
use the id to fetch some specific data (most likely from a database)
generate some js and html based on the id/data
usually this involves iframes of some sort.
To use a script rather than an html iframe has multiple advantages
you can change what is actually delivered to the users browsers without changing the include
you can resize the iframe to fit certain predefined sizes
you can inject the necessary things into the page the widget is included (of course you need to make sure this is sanctioned)
We use this all the time and we never regreted it.
If you don't want to build the widget infrastructure yourself you can always use one of the widget providers like widgetbox:
http://www.widgetbox.com/widgets/make/
With those you are up and running in no time.
This is typically called a script include.
Google have lots of these types of items, and even they call them by many names,
widgets, custom javascript, snippets, custom code, etc. It really depending on who you are writing for... I would go with "cross platform embeddable javascript code" meaning that it would need to load all its dependancies. Also specify which browsers need to be supported and what should happen is the user has javascript turned off.
EDIT :
Actually since we are talking unique IDs, you will need 2 parts probably, the user/site unique "cross platform embeddable javascript code" and whatever serverside code to support it. Basically this is an API that is accessed using your own javascript widget. Feel free you point to examples in your requirements document, programmers love examples.