On what browsers or user agents that channel URL is actually used, and what for?
I have no intention of having my site to work on Internet Explorer <= 8 (it is an HTML5 <canvas> game, and I am serving everything else as "application/xhtml+xml").
So, if channel is only useful on that old crap, I can gladly get rid of it...
Related (possibly): Channel URL Facebook
Because the social plugin is cross domain call, it needs a way to communicate. The wrokaround is to include a hidden iframe in the page for that. But, with this workaround, that iframe is loaded every time when page loads and will double the traffic reported. This is why channel url was done. What it does, it load the fb js in that page, and from that moment on, the js is available on your domain.
It will improve your loading times (cache) and will fix the reporting issue (you will see in reports channel page reported separately). But is not necessary for any html5 capable browser.
So, if you are using only HTML5 capable browsers, you are safe to ignore that. I am not sure about ie9, I will try to test it with my app by removing channel url and let you know.
Edit: By removing the channel URL from my app, I start getting double traffic reports from IE9. I think that is a good idea to keep the file there, is is just a simple html file with a single line. Better to be safe than sorry.
Related
I'm developing website with a lot of HTML5 and CSS3 features. I'm also using iframe to embed several content on my website. It works fine if I open it using Chrome/Firefox/Safari mobile browser. However, if I share on facebook (post/page) and I opened it up with Facebook application with Facebook Internal Browser, my website is messed up.
Is there any tools or way to debug on Facebook Browser? Thanks.
This is how you can do the debugging yourself. It's painful, but the only way I've come across so far.
tl;dr Get the Facebook App loading a page on your local server so you can iterate quickly. Then print debug statements directly to the page until you figure out what is going on.
Get a link to a page on your local server that you can access on your mobile device (test in mobile safari that it works). See this to find out your local IP address How do you access a website running on localhost from iPhone browser. It will look something like this
http://192.xxx.1.127:3000/facebook-test
Post that link on your Facebook page (you can make it private so your friends aren't all like WTF?)
Click the posted link in the Facebook mobile App and it will open up in Facebook's mobile browser
Since you don't have a console, you basically need to print debug statements directly to the page so it is visible. Put debug statements all over your code. If your problems are primarily related to CSS, then you can iteratively comment out stuff until you've found the issue(s) or print the relevant CSS attributes using JavaScript. Eg something like (using JQuery)
function debug(str){$('body').append("<br>"+str);}
Quite possibly the most painful part. The Facebook browser caches very aggressively. If you are making changes and nothing has happened, it's because the content is cached. You can sometimes resolve this by updating the URLs, eg /facebook-test-1, /facebook-test-2, or adding dummy parameters eg /facebook-test?dummy=1. But if the changes are in external css or js sheets it sometimes will still cache. To 100% clear the cache, delete the Facebook App from your mobile device and reinstall.
The internal browser the Facebook app uses is essentially a uiWebView. Paul Irish has made a simple iOS app that lets you load any URL into a uiWebView which you then can debug using Safari's Developer Tools.
https://github.com/paulirish/iOS-WebView-App
I found a way how to debug it easier. You will need to install the Ghostlab app (You have a 7-day free trial there, however it's totally worth paying for).
In Ghostlab, add the website address (or a localhost address) you want to debug and start the session.
Ghostlab will generate a link for access.
Copy that link and post it on Facebook (as a private post)
Open the link on mobile and that's it! Ghostlab will identify you once you open that link, and will allow you to debug the page.
For debugging, you will have all the same tools as in the Chrome devtools (how cool is that!). For example, you can tweak CSS and see the changes applied live.
If you want to debug a possible error, you can try to catch it and display it.
Put this at the very top of your code:
window.onerror = function (msg, url, lineNo, columnNo, error) {
var string = msg.toLowerCase();
var substring = "script error";
if (string.indexOf(substring) > -1){
alert('Script Error: See Browser Console for Detail');
} else {
var message = [
'Message: ' + msg,
'URL: ' + url,
'Line: ' + lineNo,
'Column: ' + columnNo,
'Error object: ' + JSON.stringify(error)
].join(' - ');
alert(message);
}
}
(Source: MDN)
This will catch and alert your errors.
Share a link on Facebook (privately), or send yourself a message on Facebook Messenger (easier). To break the cache, create a new URL every time, e.g. by appending a random string to the URL.
Follow the link and see if you can find any errors.
With help of ngrok create temporary http & https adress instead of your ordinary localhost:3000(or other port) and you could run your app on any devices. It is super easy to use.
and as it was written above all other useful information you should write somewhere inside div element (in case of React I recommend to put onClick on that div with force update or other function for getting info, sometimes it helps because JS in FB could be executed erlier than your information appears). Keep in mind that alerts are not reliable, sometimes they are blocked
bonus from ngrok that in console you will see which files was
requested and response code (it will replace lack of network tab)
and about iFrame.If you use it on other domain and you rely on cookies - you should know that facebook in-app browser blocks 3rd party cookies
test on Android and iOS separately because technicaly they use different browsers
I need to create a custom Facebook Page Tab app which will show an external site in an iframe. This need to have adverts on it but I'm not sure if this is possible as the site is hosted externally.
I'm not sure if I need to sign up to the Facebook Audience Network to get approved etc. either?
Any help or advice would be great.
Many browsers have this limitation of not allowing external sites to be shown in an iframe. Imagine the case when you are working hard to create a site and others show all your content in iframes. That is, naturally frustrating.
However, there is a candidate-solution: Let's suppose you create a page which sends a request to the other site and appends all the content into the body and head of your page. This is very much possible, so the solution is to:
Create a page in your site, let's call it outsider
In the server-side code of your outsider page send a request to the desired page to be shown
You will get the html of the page. Process it and include its content into the head and body of outsider. This includes:
3.1. Checking all the CSS to be reached, as the target page might refer to local CSS, which is unreachable locally at your end. Process the URLs of CSS files
3.2. Checking all the Javascript to be reached, as the target page might refer to local JS, which is unreachable locally at your end. Process the URLs of JS files
3.3. Apply the idea described in 3.1. and 3.2. for other resources, like images, until you are satisfied with the content of outsider
Create an iframe, having the source to point to outsider. outsider is inside your scope, so it should be shown
NOTE: If the site owning the target page does not like the possibility of you showing their content inside iframes, they might protect it by, let's say, having Javascript in their code, which checks whether the page is inside an iframe. Remove that code while processing the response to your request. If nothing else prevents you from showing the page in an iframe, then you should achieve success.
It looks like a recent Chrome update broke this by tightening mixed content (https/http) security policies, and I read that Firefox plans to do this too.
Here's the issue:
Say I set the Secure Canvas URL of my app to https://themediadudes.com/httpstest/
That page contains only a link to Google:
Google
When I view the app on Facebook and click the link, nothing happens. An error appears in the console:
[blocked] The page at https://apps.facebook.com/myappname/ ran insecure
content from http://www.google.com/.
I understand that having insecure scripts/stylesheets etc. on an https page isn't allowed, but a simple link to a different website shouldn't be blocked right?. I assume Facebook is running some scripts which do something with the page before sending the user there? Which causes the error.
If I set the target of the link to _top or _blank it works.
Ideally I want to be able to use a javascript window.location to send the user to this insecure URL, or header('Location: blah'); in PHP. But neither of those work either. And it looks like this is a bigger problem than that if even a simple link to an insecure URL doesn't work.
I thought it may be caused by whatever makes the 'fluid' canvas width and canvas height settings work. But I tried setting both width and height to fixed and the problem still happens.
Does anybody have a solution or workaround, or can anybody at least shed some more light on this?
Thanks
I've been struggling with a similar issue and the answer seems to be that it is not possible at all to reference any non-https resources from within your page tab app. Of course if a google link is all you require then that is simply resolved (as google has a https version of course) but referencing external non-https sites will always turn up this warning/block in chrome
Additionally, I should add that I have noticed that the 'page tab URL' section requires a url to a particular page, whereas the 'canvas URL' needs to link to a directory. This does not seem to be documented and will also give the insecure content message in chrome and prevent the page tab app from loading
I'm trying to create a landing page on facebook with the Static HTML application, but the image does not appear in IE8 show only at 9 and other browsers like Chrome and Firefox.
The application link is: https://www.facebook.com/hyundainic/app_128953167177144.
Yet another application that looks like:
https://www.facebook.com/SomosEskimo/app_367456286664440.
This if displayed in all browsers, except that technically I do not know if it's the same.
I'm editing the html / css and occupy absolute and relative positioning, I thought that this could affect and remove it, but the problem persists forever.
Can someone help me with this?
I think the issue is probably that you are using an absolute, non-SSL URL for the image source, and the links you posted to the app use SSL. If you leave the protocol off (example: "//whatever.com/myimage.jpg" instead of "http://whatever" or "https://whatever") the browser will use https when needed.
However, it looks like your image doesn't work over SSL:
https://hyundai.com.ni/img/quickservice-fb.jpg?id=3
You can try viewing your app using http:// and confirm it displays ok in all targeted browsers to see if this is really your issue.
I am writing an app within a facebook iframe and am unsure how best to write this. I originally wrote all the code within the main canvas.php file but found everything was running too slow before results were being loaded into the iframe.
I then tried using the php header location method so to try and load different pages into the iframe, thus reducing page load time. However, the header location is ignored.
I have also tried using javascript to get the page to load within the iframe instead, this does load in the new page but the page experiences lots of problems. It wil not pass parrameteres to itself using $_GET.
Basically, I need to perform some checks when the canvas page is first loaded in the iframe and then re-direct to another file to avoid the checks being perfomed on every page load as this seriously shows everything down. I then need to have page reloads with different parrameteres in the URL to populate the iframe with different results, again this is very slow as it has to perfomr all the checks again.
Therefore, how can I achieve a smooth workflow as a normal site within a facebook iframe?
[EDIT] Just thought is Ajax a valid option?
Many thanks in advance.
Most people experience slow response times due to not having a channelURL specified. See http://developers.facebook.com/docs/reference/javascript/
Channel File
The channel file addresses some issues with cross domain communication
in certain browsers. The contents of the channel.html file can be just
a single line:
It is important for the channel file to be cached for as long as
possible. When serving this file, you must send valid Expires headers
with a long expiration period. This will ensure the channel file is
cached by the browser which is important for a smooth user experience.
Without proper caching, cross domain communication will become very
slow and users will suffer a severely degraded experience. A simple
way to do this in PHP is:
The channelUrl parameter is optional, but recommended. Providing a
channel file can help address three specific known issues. First,
pages that include code to communicate across frames may cause Social
Plugins to show up as blank without a channelUrl. Second, if no
channelUrl is provided and a page includes auto-playing audio or
video, the user may hear two streams of audio because the page has
been loaded a second time in the background for cross domain
communication. Third, a channel file will prevent inclusion of extra
hits in your server-side logs. If you do not specify a channelUrl, you
can remove page views containing fb_xd_bust or fb_xd_fragment
parameters from your logs to ensure proper counts.
The channelUrl must be a fully qualified URL matching the page on
which you include the SDK. In other words, the channel file domain
must include www if your site is served using www, and if you modify
document.domain on your page you must make the same document.domain
change in the channel.html file as well. The protocols must also
match. If your page is served over https, your channelUrl must also be
https. Remember to use the matching protocol for the script src as
well. The sample code above uses protocol-relative URLs which should
handle most https cases properly.