There are a lot of cool tools for making powerful "single-page" JavaScript websites nowadays. In my opinion, this is done right by letting the server act as an API (and nothing more) and letting the client handle all of the HTML generation stuff. The problem with this "pattern" is the lack of search engine support. I can think of two solutions:
When the user enters the website, let the server render the page exactly as the client would upon navigation. So if I go to http://example.com/my_path directly the server would render the same thing as the client would if I go to /my_path through pushState.
Let the server provide a special website only for the search engine bots. If a normal user visits http://example.com/my_path the server should give him a JavaScript heavy version of the website. But if the Google bot visits, the server should give it some minimal HTML with the content I want Google to index.
The first solution is discussed further here. I have been working on a website doing this and it's not a very nice experience. It's not DRY and in my case I had to use two different template engines for the client and the server.
I think I have seen the second solution for some good ol' Flash websites. I like this approach much more than the first one and with the right tool on the server it could be done quite painlessly.
So what I'm really wondering is the following:
Can you think of any better solution?
What are the disadvantages with the second solution? If Google in some way finds out that I'm not serving the exact same content for the Google bot as a regular user, would I then be punished in the search results?
While #2 might be "easier" for you as a developer, it only provides search engine crawling. And yes, if Google finds out your serving different content, you might be penalized (I'm not an expert on that, but I have heard of it happening).
Both SEO and accessibility (not just for disabled person, but accessibility via mobile devices, touch screen devices, and other non-standard computing / internet enabled platforms) both have a similar underlying philosophy: semantically rich markup that is "accessible" (i.e. can be accessed, viewed, read, processed, or otherwise used) to all these different browsers. A screen reader, a search engine crawler or a user with JavaScript enabled, should all be able to use/index/understand your site's core functionality without issue.
pushState does not add to this burden, in my experience. It only brings what used to be an afterthought and "if we have time" to the forefront of web development.
What your describe in option #1 is usually the best way to go - but, like other accessibility and SEO issues, doing this with pushState in a JavaScript-heavy app requires up-front planning or it will become a significant burden. It should be baked in to the page and application architecture from the start - retrofitting is painful and will cause more duplication than is necessary.
I've been working with pushState and SEO recently for a couple of different application, and I found what I think is a good approach. It basically follows your item #1, but accounts for not duplicating html / templates.
Most of the info can be found in these two blog posts:
http://lostechies.com/derickbailey/2011/09/06/test-driving-backbone-views-with-jquery-templates-the-jasmine-gem-and-jasmine-jquery/
and
http://lostechies.com/derickbailey/2011/06/22/rendering-a-rails-partial-as-a-jquery-template/
The gist of it is that I use ERB or HAML templates (running Ruby on Rails, Sinatra, etc) for my server side render and to create the client side templates that Backbone can use, as well as for my Jasmine JavaScript specs. This cuts out the duplication of markup between the server side and the client side.
From there, you need to take a few additional steps to have your JavaScript work with the HTML that is rendered by the server - true progressive enhancement; taking the semantic markup that got delivered and enhancing it with JavaScript.
For example, i'm building an image gallery application with pushState. If you request /images/1 from the server, it will render the entire image gallery on the server and send all of the HTML, CSS and JavaScript down to your browser. If you have JavaScript disabled, it will work perfectly fine. Every action you take will request a different URL from the server and the server will render all of the markup for your browser. If you have JavaScript enabled, though, the JavaScript will pick up the already rendered HTML along with a few variables generated by the server and take over from there.
Here's an example:
<form id="foo">
Name: <input id="name"><button id="say">Say My Name!</button>
</form>
After the server renders this, the JavaScript would pick it up (using a Backbone.js view in this example)
FooView = Backbone.View.extend({
events: {
"change #name": "setName",
"click #say": "sayName"
},
setName: function(e){
var name = $(e.currentTarget).val();
this.model.set({name: name});
},
sayName: function(e){
e.preventDefault();
var name = this.model.get("name");
alert("Hello " + name);
},
render: function(){
// do some rendering here, for when this is just running JavaScript
}
});
$(function(){
var model = new MyModel();
var view = new FooView({
model: model,
el: $("#foo")
});
});
This is a very simple example, but I think it gets the point across.
When I instante the view after the page loads, I'm providing the existing content of the form that was rendered by the server, to the view instance as the el for the view. I am not calling render or having the view generate an el for me, when the first view is loaded. I have a render method available for after the view is up and running and the page is all JavaScript. This lets me re-render the view later if I need to.
Clicking the "Say My Name" button with JavaScript enabled will cause an alert box. Without JavaScript, it would post back to the server and the server could render the name to an html element somewhere.
Edit
Consider a more complex example, where you have a list that needs to be attached (from the comments below this)
Say you have a list of users in a <ul> tag. This list was rendered by the server when the browser made a request, and the result looks something like:
<ul id="user-list">
<li data-id="1">Bob
<li data-id="2">Mary
<li data-id="3">Frank
<li data-id="4">Jane
</ul>
Now you need to loop through this list and attach a Backbone view and model to each of the <li> items. With the use of the data-id attribute, you can find the model that each tag comes from easily. You'll then need a collection view and item view that is smart enough to attach itself to this html.
UserListView = Backbone.View.extend({
attach: function(){
this.el = $("#user-list");
this.$("li").each(function(index){
var userEl = $(this);
var id = userEl.attr("data-id");
var user = this.collection.get(id);
new UserView({
model: user,
el: userEl
});
});
}
});
UserView = Backbone.View.extend({
initialize: function(){
this.model.bind("change:name", this.updateName, this);
},
updateName: function(model, val){
this.el.text(val);
}
});
var userData = {...};
var userList = new UserCollection(userData);
var userListView = new UserListView({collection: userList});
userListView.attach();
In this example, the UserListView will loop through all of the <li> tags and attach a view object with the correct model for each one. it sets up an event handler for the model's name change event and updates the displayed text of the element when a change occurs.
This kind of process, to take the html that the server rendered and have my JavaScript take over and run it, is a great way to get things rolling for SEO, Accessibility, and pushState support.
Hope that helps.
I think you need this: http://code.google.com/web/ajaxcrawling/
You can also install a special backend that "renders" your page by running javascript on the server, and then serves that to google.
Combine both things and you have a solution without programming things twice. (As long as your app is fully controllable via anchor fragments.)
So, it seem that the main concern is being DRY
If you're using pushState have your server send the same exact code for all urls (that don't contain a file extension to serve images, etc.) "/mydir/myfile", "/myotherdir/myotherfile" or root "/" -- all requests receive the same exact code. You need to have some kind url rewrite engine. You can also serve a tiny bit of html and the rest can come from your CDN (using require.js to manage dependencies -- see https://stackoverflow.com/a/13813102/1595913).
(test the link's validity by converting the link to your url scheme and testing against existence of content by querying a static or a dynamic source. if it's not valid send a 404 response.)
When the request is not from a google bot, you just process normally.
If the request is from a google bot, you use phantom.js -- headless webkit browser ("A headless browser is simply a full-featured web browser with no visual interface.") to render html and javascript on the server and send the google bot the resulting html. As the bot parses the html it can hit your other "pushState" links /somepage on the server mylink, the server rewrites url to your application file, loads it in phantom.js and the resulting html is sent to the bot, and so on...
For your html I'm assuming you're using normal links with some kind of hijacking (e.g. using with backbone.js https://stackoverflow.com/a/9331734/1595913)
To avoid confusion with any links separate your api code that serves json into a separate subdomain, e.g. api.mysite.com
To improve performance you can pre-process your site pages for search engines ahead of time during off hours by creating static versions of the pages using the same mechanism with phantom.js and consequently serve the static pages to google bots. Preprocessing can be done with some simple app that can parse <a> tags. In this case handling 404 is easier since you can simply check for the existence of the static file with a name that contains url path.
If you use #! hash bang syntax for your site links a similar scenario applies, except that the rewrite url server engine would look out for _escaped_fragment_ in the url and would format the url to your url scheme.
There are a couple of integrations of node.js with phantom.js on github and you can use node.js as the web server to produce html output.
Here are a couple of examples using phantom.js for seo:
http://backbonetutorials.com/seo-for-single-page-apps/
http://thedigitalself.com/blog/seo-and-javascript-with-phantomjs-server-side-rendering
If you're using Rails, try poirot. It's a gem that makes it dead simple to reuse mustache or handlebars templates client and server side.
Create a file in your views like _some_thingy.html.mustache.
Render server side:
<%= render :partial => 'some_thingy', object: my_model %>
Put the template your head for client side use:
<%= template_include_tag 'some_thingy' %>
Rendre client side:
html = poirot.someThingy(my_model)
To take a slightly different angle, your second solution would be the correct one in terms of accessibility...you would be providing alternative content to users who cannot use javascript (those with screen readers, etc.).
This would automatically add the benefits of SEO and, in my opinion, would not be seen as a 'naughty' technique by Google.
Interesting. I have been searching around for viable solutions but it seems to be quite problematic.
I was actually leaning more towards your 2nd approach:
Let the server provide a special website only for the search engine
bots. If a normal user visits http://example.com/my_path the server
should give him a JavaScript heavy version of the website. But if the
Google bot visits, the server should give it some minimal HTML with
the content I want Google to index.
Here's my take on solving the problem. Although it is not confirmed to work, it might provide some insight or idea's for other developers.
Assume you're using a JS framework that supports "push state" functionality, and your backend framework is Ruby on Rails. You have a simple blog site and you would like search engines to index all your article index and show pages.
Let's say you have your routes set up like this:
resources :articles
match "*path", "main#index"
Ensure that every server-side controller renders the same template that your client-side framework requires to run (html/css/javascript/etc). If none of the controllers are matched in the request (in this example we only have a RESTful set of actions for the ArticlesController), then just match anything else and just render the template and let the client-side framework handle the routing. The only difference between hitting a controller and hitting the wildcard matcher would be the ability to render content based on the URL that was requested to JavaScript-disabled devices.
From what I understand it is a bad idea to render content that isn't visible to browsers. So when Google indexes it, people go through Google to visit a given page and there isn't any content, then you're probably going to be penalised. What comes to mind is that you render content in a div node that you display: none in CSS.
However, I'm pretty sure it doesn't matter if you simply do this:
<div id="no-js">
<h1><%= #article.title %></h1>
<p><%= #article.description %></p>
<p><%= #article.content %></p>
</div>
And then using JavaScript, which doesn't get run when a JavaScript-disabled device opens the page:
$("#no-js").remove() # jQuery
This way, for Google, and for anyone with JavaScript-disabled devices, they would see the raw/static content. So the content is physically there and is visible to anyone with JavaScript-disabled devices.
But, when a user visits the same page and actually has JavaScript enabled, the #no-js node will be removed so it doesn't clutter up your application. Then your client-side framework will handle the request through it's router and display what a user should see when JavaScript is enabled.
I think this might be a valid and fairly easy technique to use. Although that might depend on the complexity of your website/application.
Though, please correct me if it isn't. Just thought I'd share my thoughts.
Use NodeJS on the serverside, browserify your clientside code and route each http-request's(except for static http resources) uri through a serverside client to provide the first 'bootsnap'(a snapshot of the page it's state). Use something like jsdom to handle jquery dom-ops on the server. After the bootsnap returned, setup the websocket connection. Probably best to differentiate between a websocket client and a serverside client by making some kind of a wrapper connection on the clientside(serverside client can directly communicate with the server). I've been working on something like this: https://github.com/jvanveen/rnet/
Use Google Closure Template to render pages. It compiles to javascript or java, so it is easy to render the page either on the client or server side. On the first encounter with every client, render the html and add javascript as link in header. Crawler will read the html only but the browser will execute your script. All subsequent requests from the browser could be done in against the api to minimize the traffic.
This might help you : https://github.com/sharjeel619/SPA-SEO
Logic
A browser requests your single page application from the server,
which is going to be loaded from a single index.html file.
You program some intermediary server code which intercepts the client
request and differentiates whether the request came from a browser or
some social crawler bot.
If the request came from some crawler bot, make an API call to
your back-end server, gather the data you need, fill in that data to
html meta tags and return those tags in string format back to the
client.
If the request didn't come from some crawler bot, then simply
return the index.html file from the build or dist folder of your single page
application.
I've got a product that embeds into websites similarly to Paypal (customers add my button to their website, users click on this button and once the service is complete I redirect them back to the original website).
I'd like to demo my technology to customers without actually modifying their live website. To that end, is it possible to configure http://stackoverflow.myserver.com/ so it mirrors http://www.stackoverflow.com/ while seamlessly injecting my button?
Meaning, I want to demo the experience of using my button on the live website without actually re-hosting the customer's database on my server.
I know there are security concerns here, so feel free to mention them so long as we meet the requirements. I do not need to demo this for website that uses HTTPS.
More specifically, I would like to demonstrate the idea of financial bounties on Stackoverflow questions by injecting a Paypal button into the page. How would I demo this off http://stackoverflow.myserver.com/ without modifying https://stackoverflow.com/?
REQUEST TO REOPEN: I have reworded the question to be more specific per your request. If you still believe it is too broad, please help me understand your reasoning by posting a comment below.
UPDATE: I posted a follow-up challenge at How to rewrite URLs referenced by Javascript code?
UPDATE2: I discarded the idea of bookmarklets and Greasemonkey because they require customer-side installation/modification. We need to make the process as seamless as possible, otherwise many of get turned off by the process and won't let us pitch.
I would suggest to create a proxy using a HTTP handler.
In the ProcessRequest you can do a HttpWebRequest to get the content on the other side, alter it and return the adjusted html to the browser. You can rewrite the urls inside to allow the loading of images, etc from the original source.
public void ProcessRequest(HttpContext context)
{
// get the content using HttpWebRequest
string html = ...
// alter it
// write back the adjusted html
context.Response.Write(html);
}
If you're demoing on the client-side and looking to just hack it in quickly, you could pull it off with some jQuery. I slapped the button after the SO logo just for a demo. You could type this into your console:
$('head').append('<script src="https://www.paypalobjects.com/js/external/dg.js" type="text/javascript"></script>')
$('#hlogo').append('<form action="https://www.sandbox.paypal.com/webapps/adaptivepayment/flow/pay" target="PPDGFrame" class="standard"><label for="buy">Buy Now:</label><input type="image" id="submitBtn" value="Pay with PayPal" src="https://www.paypalobjects.com/en_US/i/btn/btn_paynowCC_LG.gif"><input id="type" type="hidden" name="expType" value="light"><input id="paykey" type="hidden" name="paykey" value="insert_pay_key">')
var embeddedPPFlow = new PAYPAL.apps.DGFlow({trigger: 'submitBtn'});
Now, I'm not sure if I did something wrong or not because I got this error on the last part:
Expected 'none' or URL but found 'alpha('. Error in parsing value for 'filter'. Declaration dropped.
But at any rate if you are demoing you could just do this, maybe as a plan B. (You could also write a userscript for this so you don't have to open the console, I guess?)
After playing with this for a very long time I ended up doing the following:
Rewrite the HTML and JS files on the fly. All other resources are hosted by the original website.
For HTML files, inject a <base> tag, pointing to the website being redirected. This will cause the browser to automatically redirect relative links (in the HTML file, CSS files, and even Flash!) to the original website.
For the JS files, apply a regular expression to patch specific sections of code that point to the wrote URL. I load up the redirected page in a browser, look for broken links, and figure out which section of JS needs to be patched to correct the problem.
This sounds a lot harder than it actually is. On average, patching each page takes less than 5 minutes of work.
The big discovery was the <base> tag! It corrected the vast majority of links on my behalf.
Can i add the content part of this link into my webpage
http://rid3201.org/site/club_members2.php?id=MTk3Ng==
I want to avoid the header part.Can i use iframe or object for this.
Use Html Agility Pack
With it you can get the whole page and select only the html element you need (I assume it would be table).
Then you can pass it to your page.
If you own the domain rid3201.org, you can do it with jQuery:
$('#result').load('ajax/test.html #container');
heads up!
If are not the owner of the domain, you CAN'T do it via jQuery.
The documentation of .load() says:
Due to browser security restrictions, most "Ajax" requests are subject
to the same origin policy; the request can not successfully retrieve
data from a different domain, subdomain, or protocol.
An alternative to jQuery is using XMLHttpRequest, coding with a backend language, like .Net
After you catch the url source, you have to clean the code to get only the div you want.
Lets say I have example.html and inside that i have a code like
<iframe src="x.com" id="x"></iframe>
from x.com, I would like to get everything inside
<div class="content">...</div>
into example.html inside
<div class="xCodes">ONTO HERE</div>
So I tried to get the elements inside x.com to show up on example.html and I heard it's not possible to access them for cross domain problems.
I was wondering if there was another way to retrieve HTML tags from x.html into example.html
Maybe without using <iframe />??
Sourced from: http://james.padolsey.com/javascript/cross-domain-requests-with-jquery/
$('.xCodes').load('http://x.com/x.html');
OR
$.ajax({
url: 'http://x.com/x.html',
type: 'GET',
success: function(res) {
var data = $(res.responseText).find('.content').text();
$('.xCodes').html(data);
}
});
If I understand correctly you want to rip the content from a DIV on one site and display it on another. There are several issues with this, but I'll focus on the technological aspect and assume you are acting in good faith with pulling the content.
The real issue you're running up against here is that you don't have access to DOM elements of pages that haven't loaded yet. As such you need to tell the browser to load the data for that page so that you can access the elements that should have loaded on the page and then pull the information out. JQuery has a nice little method to help with that called .load() (http://api.jquery.com/load/).
As an important side note however you can't do this as all modern broswers forbid cross site access in such a manner:
From the JQuery .load() page:
Additional Notes:
Due to browser security restrictions, most "Ajax" requests are subject to the same origin policy; the request can not successfully retrieve data from a different domain, subdomain, or protocol.
And check out:
http://en.wikipedia.org/wiki/Same_origin_policy
One more bit of warning. If you don't control the code on the other site you are potentially exposing yourself to serious security issues so only do this in situations where you have control of the other site or for some reason have absolute faith in that site. Alternatively you should try to, if available, use APIs for the sites/services you are trying to get data from.
I'm paginating a list of items, and currently the page listed on page load is set by a GET variable (e.g. www.example.com/page.html?page=2). I want to switch it to ajax, but I'm worried users won't be able to bookmark the page they want to view.
Is there a way I can update the URL without redirecting the page?
Use hash
Your website is www.example.com/page.html
Part I.
When you load page two using ajax add a hash to the url
www.example.com/page.html#page2
You can do that using javascript
window.location.hash = "page2".
Now users can bookmark www.example.com/page.html#page2
part II.
When a user request a page say, www.example.com/page.html#page2
You can read the hash using javascript.
var myHash = window.location.hash
If myHash is empty load the page normally.
If it contains "page2", then load the content of page2.
Yes, with a hash in the url. You can learn more here.
You can also find a nice jquery plugin for that purpose here.
Regards