Google Maps API - Slow loading javascript - javascript

I am using Google Maps API to display a map on a certain page.
Problem is that the file http://maps.google.com/maps?file=api..... sometimes happens to load very slow - decreasing the page's performance, because the rest of the JavaScript is first loaded on document ready, which its rarely reaches - because the browser locks up waiting for the file from Google.
I have tried to move the JavaScript file from the <head> tag to under my content. But the rest of the JavaScript is never fired because the browser waits for the file from Google.
Is there a way around this, or have anyone else experienced same problem? It began recently, and I have no idea why.
This is my code, if anyone is interested:
<script type="text/javascript" src="http://maps.google.com/maps?file=api&v=2&sensor=true&key=ABQIAAAAa24xicak8_ghHX58i7La7hRFh9iM79SNC94rOejOtdMRvQmJiBS6Uv5F_1BNSh9ZuSzFXyekHISgew"> </script>
<script type="text/javascript" src="/js/maps.js"></script>
<script type="text/javascript">
$(document).ready(function() {
// Google Maps
initialize();
// Other JavaScript comes here....
});
</script>
If I access
http://maps.google.com/maps?file=api&v=2&sensor=true&key=ABQIAAAAa24xicak8_ghHX58i7La7hRFh9iM79SNC94rOejOtdMRvQmJiBS6Uv5F_1BNSh9ZuSzFXyekHISgew
The file loads instantly.

This is a rather old question now - the solution was to disable firebug (atleast for me).

Use Google's Ajax APIs. From some time past, all of Google's services can be accessed through the JavaScript API. It's a modular system, you only have to include the JSAPI library, and then you can dynamically load the modules you need—it won't block your site.
<script type="text/javascript"
src="http://www.google.com/jsapi?key=ABCDEFG"></script>
<script type="text/javascript">
google.load("maps", "2");
google.setOnLoadCallback(function() {
// Your logic goes here.
// It will be run right after the maps module was loaded.
});
</script>
For further details, see JSAPI's developer documentation.

On JavaScript optimization: always put your JS at the bottom of your even your Maps API script. I can't really think of any good reason to have any JS in the head.

Related

Unknown Browser Issues with Javascript

I am having some weird issues getting with javascript running on a friend's machine. I have a form wizard that perform certain checks and operations. I use external jquery and bootstrap libraries with a custom script also. The script works on all browsers I've test so far including old IE , however a friend reports the following errors when accessing the form url.
The strange thing to me is every error is on line 1 and haven't touched any of the libraries.
External Library linking
<script src="assets/js/jquery-1.11.1.min.js"></script>
<script src="assets/bootstrap/js/bootstrap.min.js"></script>
<script src="assets/js/jquery.backstretch.min.js"></script>
<script src="assets/js/retina-1.1.0.min.js"></script>
<script src="assets/js/scripts.js"></script>
custom script.js overview
jQuery(document).ready(function() {
...
// javascript code
...
});
Anything I should try or do?

FBInstant is not defined

Sentry is showing that certain Facebook users are receiving the error:
FBInstant is not defined
My HTML file includes scripts like so just after the opening <body> tag:
<script src="https://connect.facebook.net/en_US/fbinstant.6.2.js"></script>
<script src="js/jquery-3.3.1.min.js"></script>
<script src="js/app.js"></script>
In app.js, FBInstant.initializeAsync is only called after the entire page has loaded:
window.onload = function() {
FBInstant.initializeAsync().then(function() {
//Load stuff, etc.
});
}
Is fbinstant.6.2.js not being loaded for some reason? This is working for the vast majority of people. It seems to be mostly Chrome users, with a smaller portion of Firefox users as well.
You should always check if it exists before using it, i had the same problem with the JS SDK of Facebook and found out that those people just installed a browser plugin like Ghostery to disable third party plugins.

javascript doesn't work in Cordova project

i have a web project which works find in web. I want to transfer it into phonegap windows phone project .
Everything works fine but in a search option whenever i click in the search option it shows nothing showing a message "We are having trouble to display this message". N:B: this search option works properly in the web.
here is my search code:
<script src="https://code.jquery.com/jquery-2.1.1.min.js"></script>
<script src="js/materialize.min.js"></script>
<script src="js/init.js"></script>
<script>
var c=getCatalogue();
var bestNew=getBestNew();
$("#recherche").click(function(){
var v=$("#search").val();
window.localStorage.setItem("search",v);
if(v!="") routePage("recherche.html?search="+v);
});
</script>
I think problem is when i pass the value to another page that is "search="+v".
When i use if(v!="") routePage("recherche.html); instead of if(v!="") routePage("recherche.html?search="+v); then it works.
Try downloading and using JavaScript imports locally instead of fetching a remote version if not strictly necessary.
See:
<script src="https://code.jquery.com/jquery-2.1.1.min.js"></script>
Also phonegap.js should be included:
<script type="text/javascript" src="phonegap.js"></script>
You will need to move the JQuery source to a local file and update your script tag, like you have with materialize.min.js. Loading library JS from the network is not a good idea as it slows your app's startup down and also will cause it to fail when started in a situation where there is no network access.
Additionally Cordova/PhoneGap's Content Security Policy may be blocking remote script loads for security reasons - you don't state which PhoneGap/Cordova version you are using, but this may be a problem for you in Cordova 5. There's a tutorial on dealing with that here. You can configure around this by adjusting the Content Security Policy meta tag to allow script-src from other than "self" but I wouldn't recommend this.
When running in Cordova/PhoneGap you should also wait for the "deviceready" event before trying to do anything, to make sure that the framework is fully initialized and that you have access to call plugins.
Also instead of loading new pages you should architect your app so that it is a single page app and generates page fragments from templates as needed. Try looking at something like Handlebars for this unless you have another preferred solution. I have a complete demo app that uses this approach that you can look at the source for here.

How do I ensure my javascript only executes after all external <script src="..."> have loaded their contents?

Our website uses the Google API to execute google searches. The problem I am experiencing is that the following code fails...
<script src="https://www.google.com/jsapi" type="text/javascript"></script>
<script type="text/javascript">
google.load('search', '1');
</script>
It fails with the following error message:
'google' is undefined
My guess is that this is happening because the Google API has not loaded completely before the script executes.
Should I use JQuery's document.ready? I read that this will start executing script when the DOM has finished loading. I assume this does not include loading external resources like scripts, stylesheets and images?
No-repro
<script src="http://google.com/jsapi"></script>
<script>google.load("jquery", "1");</script>
<script>alert($);</script>
It does work, there is no need for an API key.
Can you check the request it is making? (with Firebug or something) It might be a problem with your connection... That is why there is a fallback for jQuery you can implement. As for the loader you will have to check why the request is failing.
Unless you specify defer or async attributes, <script>s always load and execute sequentially; the second script will only be executed after the first one has loaded and executed. (Note that this doesn’t necessarily mean you’ll already notice a difference at this point; for example, I could execute the script window.onload = function() { alert(42); }; right now, but I will only see its result when the onload event fires.)
If you’re using this code:
<script src="https://www.google.com/jsapi"></script>
<script>
google.load('search', '1');
</script>
And you get an error message saying google is undefined, it means the first script failed to load.

Where do you include the jQuery library from? Google JSAPI? CDN?

There are a few ways to include jQuery and jQuery UI and I'm wondering what people are using?
Google JSAPI
jQuery's site
your own site/server
another CDN
I have recently been using Google JSAPI, but have found that it takes a long time to setup an SSL connection or even only to resolve google.com. I have been using the following for Google:
<script src="https://www.google.com/jsapi"></script>
<script>
google.load('jquery', '1.3.1');
</script>
I like the idea of using Google so it's cached when visiting other sites and to save bandwidth from our server, but if it keeps being the slow portion of the site, I may change the include.
What do you use? Have you had any issues?
Edit: Just visited jQuery's site and they use the following method:
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js"></script>
Edit2: Here's how I've been including jQuery without any problems for the last year:
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.4.3/jquery.min.js"></script>
The difference is the removal of http:. By removing this, you don't need to worry about switching between http and https.
Without a doubt I choose to have JQuery served by Google API servers. I didn't go with the jsapi method since I don't leverage any other Google API's, however if that ever changed then I would consider it...
First: The Google api servers are distributed across the world instead of my single server location: Closer servers usually means faster response times for the visitor.
Second: Many people choose to have JQuery hosted on Google, so when a visitor comes to my site they may already have the JQuery script in their local cache. Pre-cached content usually means faster load times for the visitor.
Third: My web hosting company charges me for the bandwidth used. No sense consuming 18k per user session if the visitor can get the same file elsewhere.
I understand that I place a portion of trust on Google to serve the correct script file, and to be online and available. Up to this point I haven't been disappointed with using Google and will continue this configuration until it makes sense not to.
One thing worth pointing out... If you have a mixture of secure and insecure pages on your site you might want to dynamically change the Google source to avoid the usual warning you see when loading insecure content in a secure page:
Here's what I came up with:
<script type="text/javascript">
document.write([
"\<script src='",
("https:" == document.location.protocol) ? "https://" : "http://",
"ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js' type='text/javascript'>\<\/script>"
].join(''));
</script>
UPDATE 9/8/2010 -
Some suggestions have been made to reduce the complexity of the code by removing the HTTP and HTTPS and simply use the following syntax:
<script type="text/javascript">
document.write("\<script src='//ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js' type='text/javascript'>\<\/script>");
</script>
In addition you could also change the url to reflect the jQuery major number if you wanted to make sure that the latest Major version of the jQuery libraries were loaded:
<script type="text/javascript">
document.write("\<script src='//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js' type='text/javascript'>\<\/script>");
</script>
Finally, if you don't want to use Google and would prefer jQuery you could use the following source path (keep in mind that jQuery doesn't support SSL connections):
<script type="text/javascript">
document.write("\<script src='http://code.jquery.com/jquery-latest.min.js' type='text/javascript'>\<\/script>");
</script>
One reason you might want to host on an external server is to work around the browser limitations of concurent connections to particular server.
However, given that the jQuery file you are using will likely not change very often, the browser cache will kick in and make that point moot for the most part.
Second reason to host it on external server is to lower the traffic to your own server.
However, given the size of jQuery, chances are it will be a small part of your traffic. You should probably try to optimize your actual content.
jQuery 1.3.1 min is only 18k in size. I don't think that's too much of a hit to ask on the initial page load. It'll be cached after that. As a result, I host it myself.
If you want to use Google, the direct link may be more responsive. Each library has the path listed for the direct file. This is the jQuery path
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.1/jquery.min.js"></script>
Just reread your question, is there a reason your are using https? This is the script tag Google lists in their example
<script src="http://www.google.com/jsapi"></script>
I wouldn't want any public site that I developed to depend on any external site, and thus, I'd host jQuery myself.
Are you willing to have an outage on your site when the other (Google, jquery.com, etc.) goes down? Less dependencies is the key.
Pros: Host on Google has benefits
Probably faster (their servers are more optimised)
They handle the caching correctly - 1 year (we struggle to be allowed to make the changes to get the headers right on our servers)
Users who have already had a link to the Google-hosted version on another domain already have the file in their cache
Cons:
Some browsers may see it as XSS cross-domain and disallow the file.
Particularly users running the NoScript plugin for Firefox
I wonder if you can INCLUDE from Google, and then check the presence of some Global variable, or somesuch, and if absence load from your server?
There are a few issues here. Firstly, the async load method you specified:
<script type="text/javascript" src="https://www.google.com/jsapi"></script>
<script type="text/javascript">
google.load('jquery', '1.3.1');
google.setOnLoadCallback(function() {
// do stuff
});
</script>
has a couple of issues. Script tags pause the page load while they are retrieved (if necessary). Now if they're slow to load this is bad but jQuery is small. The real problem with the above method is that because the jquery.js load happens independently for many pages, they will finish loading and render before jquery has loaded so any jquery styling you do will be a visible change for the user.
The other way is:
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.1/jquery.min.js"></script>
Try some simple examples like, have a simple table and change the background of the cells to yellow with the setOnLoadCallback() method vs $(document).ready() with a static jquery.min.js load. The second method will have no noticeable flicker. The first will. Personally I think that's not a good user experience.
As an example run this:
<html>
<head>
<title>Layout</title>
<style type="text/css">
.odd { background-color: yellow; }
</style>
</head>
<body>
<table>
<tr><th>One</th><th>Two</th></tr>
<tr><td>Three</td><td>Four</td></tr>
<tr><td>Five</td><td>Six</td></tr>
<tr><td>Seven</td><td>Nine</td></tr>
<tr><td>Nine</td><td>Ten</td></tr>
</table>
<script src="http://www.google.com/jsapi"></script>
<script>
google.load("jquery", "1.3.1");
google.setOnLoadCallback(function() {
$(function() {
$("tr:odd").addClass("odd");
});
});
</script>
</body>
</html>
You (should) see the table appear and then the rows go yellow.
The second problem with the google.load() method is that it only hosts a limited range of files. This is a problem for jquery since it is extremely plug-in dependent. If you try and include a jquery plugin with a <script src="..."> tag and google.load() the plug-in will probably fail with messages of "jQuery is not defined" because it hasn't loaded yet. I don't really see a way around this.
The third problem (with either method) is that they are one external load. Assuming you have some plugins and your own Javascript code you're up to a minimum of two external requests to load your Javascript. You're probably better off getting jquery, all relevant plug-ins and your own code and putting it into one minified file.
From Should You Use Google's Ajax Libraries API for Hosting?:
As to load times, you're actually
loading two scripts - the jsapi script
and the mootools script (the
compressed version from above). So
that is two connections, rather than
one. In my experience, I found that
the load time was actually 2-3 times
slower than loading from my own
personal shared server, even though it
was coming from Google, and my version
of the compressed file was a couple of
K larger than Google's. This, even
after the file had loaded and
(presumably) cached. So for me, since
the bandwidth doesn't matter much,
isn't going to matter.
Lastly you have the potential problem of a paranoid browser flagging the request as some sort of XSS attempt. It's not typically a problem with default settings but on corporate networks where the user may not have control over which browser they use let alone the security settings you may have a problem.
So in the end I can't really see me using the Google AJAX API for jQuery at least (the more "complete" APIs are a different story in some ways) much except to post examples here.
In addition to people who advices to host it on own server, I'd proposed to keep it on separate domain (e.g. static.website.com) to allow browsers to load it into separate from other content thread. This tip also works for all static stuff, say images and css.
I have to vote -1 for the libraries hosted on Google. They are collecting data, google analytics style, with their wrappers around these libraries. At a minimum, I don't want a client browser doing more than I'm asking it to do, much less anything else on the page. At worse, this is Google's "new version" of not being evil -- using unobtrusive javascript to gather more usage data.
Note: if they've changed this practice, super. But the last time I considered using their hosted libraries, I monitored the outbound http traffic on my site, and the periodic calls out to google servers were not something I expected to see.
I might be old-school about this, but I still frown on hotlinking. Maybe Google is the exception, but in general, it's really just good manners to host the files on your own server.
I will add this as a reason to locally host these files.
Recently a node in Southern California on TWC has not been able to resolve the ajax.googleapis.com domain (for users with IPv4) only so we are not getting the external files. This has been intermittant up until yesterday (now it is persistant.) Because it was intermittant, I was having tons of problems troubleshooting SaaS user issues. Spent countless hours trying to track why some users were having no issues with the software, and others were tanking. In my usual debugging process I'm not in the habit of asking a user if they have IPv6 turned off.
I stumbled on the issue because I myself was using this particular "route" to the file and also am using only IPV4. I discovered the issue with developers tools telling me jquery wasn't loading, then started doing traceroutes etc... to find the real issue.
After this, I will most likely never go back to externally hosted files because: google doesn't have to go down for this to become a problem, and... any one of these nodes can be compromised with DNS hijacking and deliver malicious js instead of the actual file. Always thought I was safe in that a google domain would never go down, now I know any node in between a user and the host can be a fail point.
I just include the latest version from the jQuery site: http://code.jquery.com/jquery-latest.pack.js It suits my needs and I never have to worry about updating.
EDIT:For a major web app, certainly control it; download it and serve it yourself. But for my personal site, I could not care less. Things don't magically disappear, they are usually deprecated first. I keep up with it enough to know what to change for future releases.
Here some useful resource, hope can help you to chose your CDN.
MS has recently add a new domain for delivery Libraries trough their CDN.
Old Format: http://ajax.microsoft.com/ajax/jQuery/jquery-1.5.1.js
New Format: http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.5.1.js
This should not send all cookies for microsoft.com.
http://www.asp.net/ajaxlibrary/cdn.ashx#Using_jQuery_from_the_CDN_11
Here some statistics about most popular technology used on the web across all technology.
http://trends.builtwith.com/
Hope can help you to choose.
If I am responsible for the 'live' site I better be aware of everything that is going
on and into my site. For that reason I host the jquery-min version myself either on the same server or a static/external server but either way a location where only I (or my program/proxy) can update the library after having verified/tested every change
In head:
(function() {
var jsapi = document.createElement('script'); jsapi.type = 'text/javascript'; jsapi.async = true;
jsapi.src = ('https:' == document.location.protocol ? 'https://' : 'http://') + 'www.google.com/jsapi?key=YOUR KEY';
(document.getElementsByTagName('head')[0] || document.getElementsByTagName('head')[0]).appendChild(jsapi);
})();
End of Body:
<script type="text/javascript">
google.load("jquery", "version");
</script>
I host it with my other js files on my own server, and, that's that point, combine and minify them (with django-compresser, here, but that's not the point) to be served as just one js file, with everything the site needs put into it. You'll need to serve your own js files anyway, so I see no reason to not add the extra jquery bytes there too - some more kbs are much more cheaper to transfer, than more requests to be made. You are not dependent to anyone, and as soon as your minified js is cached, you're super fast as well.
On first load, a CDN based solution might win, because you must load the additional jquery kilobytes from your own server (but, without an additional request). I doubt the difference is noticable, though. And then, on a first load with cleared cache, your own hosted solution will probably always be much faster, because of more requests (and DNS lookups) needed, to fetch the CDN jquery.
I wonder how this point is almost never mentioned, and how CDNs seem to take over the world :)

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