What's the best way to load fast javascript in different pages ? Should my custom javascripts go separate for each page or all custom javascripts should be present only in 1 common custom.js file and include this file in footer ?
require_once($header);
include_once($page2.php);
require_once($footer);
<script src="js/custom-page2.js"></script>//separate for each page
require_once($header);
include_once($page1.php);
require_once($footer);
<script src="js/custom-page1.js"></script>//separate for each page
OR
//in footer.php include all js in 1 file
<script src="js/all-custom.js"></script>
If all pages share the same scripts using one script will be better.
If they use different scripts you can cut out what each page DOESN'T need and save on HTTP requests.
Or a mixture of the two.
So...it depends?
Basic rule: If you don't need it, don't load it.
I advise you to create your html page by including in this order :
HTML wrap all
Head (with style in one page for example)
Body with:
Javascript modules
Main HTML DOM
Javascript DOM modifiers and launchers
Same like this :
<html>
<head>
<link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>
<script type="text/javascript" src="modules.js"></script>
<div class="body"></div>
<script type="text/javascript" src="functions.js"></script>
</body>
</html>
it's good idea to put all js in header (browser will not render page until all header files are loaded, at least in theory).
browser (proxy etc) will cache your js, so it's not going to be fetched from your site on every request. browser will only check if file has changed.
in most cases browser will keep single connection for all requests, however it still has to ask for every single js file if it hasn't changed. i keep js logic in small seperate files during development, but then i merge them for production.
Related
i am trying to reduce my webpage load time . When i am searching i come to this point preload css and javascript .
So i am trying to implement this in my html page please see my html code before and after implementation
before
<html>
<head>
<link href="http://fonts.googleapis.com/css?family=lato:400,100,200,300,500%7COpen+Sans:400,300,600,700,800%7COswald:300,400,700" rel="stylesheet" type="text/css"> ...........
</head>
<body>
html contents
<script src="assets/js/jquery-1.12.4.min.js" type="text/javascript"></script>
</body>
</html>
After implementation i change like this
<html>
<head>
<link rel="preload" href="http://fonts.googleapis.com/css?family=lato:400,100,200,300,500%7COpen+Sans:400,300,600,700,800%7COswald:300,400,700" as="style">
<link rel="preload" href="assets/js/jquery-1.12.4.min.js" as="script">
<link rel="stylesheet" href="http://fonts.googleapis.com/css?family=lato:400,100,200,300,500%7COpen+Sans:400,300,600,700,800%7COswald:300,400,700">
</head>
<body>
html contents
<script src="assets/js/jquery-1.12.4.min.js"></script>
</body>
</html>
But i can't notice any increase in speed . So please help to make this in correct way
i read the following article
https://developer.mozilla.org/en-US/docs/Web/HTML/Preloading_content .
But i can't figure out . Please help .
Or is there is any better method for page speed ?
Why this doesn't work
Preloading resources that are loaded directly in the HTML is useless. This is because the browser reads the preload at the same time as the actual resource reference.
Preloading is useful to reduce the length of your request waterfall.
Imagine the following situation:
style.css
body {
background-image: url(myimage.png);
}
index.html
<html>
<head>
<link rel="stylesheet" href="style.css" />
</head>
<body>
</body>
</html>
The process of loading the above page consists (roughly) of the following steps:
Download index.html
Parse the HTML file
Because of the link tag, download style.css
Parse the CSS file
Because of the background-image, download myimage.png
Parse the image and display it on the screen
This means your request waterfall is index.html -> style.css -> myimage.png.
By adding a preload for myimage.png the browser can download the image earlier, so your request waterfall becomes:
index.html +-> style.css
+-> myimage.png
Instead of 3, it is now only 2 requests long, which means faster load times.
What else can you do to improve (perceived) page load times?
Some common ways are:
Minify your assets (JavaScript, stylesheets)
Ensure your server has compression enabled for static assets
Only load resources actually required on page load first, then load other scripts later (like those for user interactions).
But to get a better overall view of the things you can improve you can use the Chrome Audit system (Lighthouse).
https://developers.google.com/web/updates/2016/03/link-rel-preload
See the above article link. I saw the link shared above. Preload never makes the page load the page fast. It only gives the priority to the files which is declared rel="preload" to load very early as the page loads up. You can read the article again Also the article shared by me. It will say the same.
You will need other methods to load the page fast. This method will not be helpful. There are few methods listed below you can use to make page load faster.
You can minify css and js files which will load very very fast than normal file.
You can minify script and css files from (https://www.minifier.org/) here.
Avoid external links of css and js files
Avoid spaces and Newlines in code.
Use compressed images which will also load faster.
Enable Caching.
I wanted to use the loading page from here http://www.gayadesign.com/diy/queryloader-preload-your-website-in-style/
because the personal website I was making is very poorly optimized and loads quite slowly
The loading page works fine if I make it a seperate page and then redirect to my home page like so:
http://matthewpiatetsky.com/cs103/demo/demo.html
However, I have also tried adding this same animation when I go directly to the page, and it does not work. I think this is because of the other js files present in the document.
http://matthewpiatetsky.com/cs103/
In the redirecting page the script is located here and it works.
http://matthewpiatetsky.com/cs103/demo/js/script.js
In the actual page the script is located here and it doesn't work.
http://matthewpiatetsky.com/cs103/js/matthew.js
The script declarations in the actual page look like this, so this script is called last. Calling it first breaks the page, so I'm guessing the 5-grid js is the problem.
<script src="js/jquery-1.9.1.min.js"></script>
<script src="css/5grid/init.js?use=mobile,desktop"></script>
<script src="js/jquery.formerize-1.1.js"></script>
<script src="js/init.js"></script>
<script src="path/to/file/jquery.queryloader2.js" type="text/javascript"></script>
<script type="text/javascript" src="js/matthew.js"></script>
It looks like you are missing a plugin. Your code tries to use the QueryLoader2 plugin on line 19 of Matthew.js, but you don't have this plugin included on your page.
I currently am working on a large site with many different issues to contend with. One being that I have no easy way to include a script into my <head> without manually doing it for 500+ pages.
I have the possibility to include jQuery.min just inside the <body> tag from an include located there.
My question is, aside it not being a standard implementation, would there be any negative effects from not loading jQuery within the <head> tag? Will all the functions be available?
I am aware that if I do this, I will not be able to call jQuery from within the <head> or before this include... that's okay.
example:
<head>
Standard Head Stuff
</head>
<body>
<div>Some Content</div>
<!-- My Include is roughly here -->
<script type="text/javascript" src="jquery.min.js"></script>
<div>More content</div>
<script type="text/javascript">
$(document).ready(function(){
// Put my jQuery commands here
});
</script>
</body>
The only issue is that a page is loaded from top to bottom and so if you were to place the include statement into the header than you would be assured that the library would be loaded immediately. Otherwise the library may only be loaded at a later time which can cause a delay in some effects potentially.
Head or body, inline code will execute when phrased. Code is generally placed in the head so external libraries can be loaded before the page is (so effects can be run on dom ready). Code in the body will be run once the dom is done with the header code, and done loading page elements (once in the body, elements are loaded from top to bottom). So any code in the body will be executed once the page had loaded (up to that point)
The following external CSS files were
included after an external JavaScript
file in the document head. To ensure
CSS files are downloaded in parallel,
always include external CSS before
external JavaScript. 1 inline script
block was found in the head between an
external CSS file and another
resource. To allow parallel
downloading, move the inline script
before the external CSS file, or after
the next resource.
My HTML is:
<head>
<link rel="Stylesheet" href="gStyle.css" />
<script type="text/javascript" src="gMain.js"></script>
<script type="text/javascript" language="javascript">
// Your chart object(s)
var myChart;
// Function to hold all chart creation
function initCharts() {
myChart = new ganttChart("chart1");
myChart.gAddBar("Dynamic!", "22/3/2010", "3/4/2010");
myChart.gLoadData("Going to the shop*4/3/2010*19/3/2010*Watching TV*9/3/2010*23/3/2010*Watching TV*1/3/2010*23/3/2010*Watching TV*18/3/2010*28/3/2010*END INPUT*1/3/2010*9/3/2010");
myChart.gDraw();
myChart.gChangeBarColour(1, "#dd2200");
myChart.gChangeBarColour(2, "#9900ee");
myChart.gChangeBarColour(3, "#00dd00");
myChart.gChangeBarColour(4, "#ffbb00");
myChart.gChangeBarColour(5, "#00aa99");
}
</script>
</head>
<body onload="initCharts()">
<div id="chart1" class="gContainer">
</div>
<div id="db"></div>
</body>
Is it getting confused between the body inline script?
Inspect the page elements. Probably your Chrome extensions are dynamically adding scripts to the page in HEAD.
I think that when javascript is downloaded the browser must wait to get it all and then run it - this stops it going to the next line directly and getting it. I guess styles all get downloaded and then computed down to inheritance position and importance etc...so they can download in parallel.
This kind of thing is hard to regulate in a CMS with components that load their own style and js.
For me, Google Analytics library inserted scripts before the rest of mine.
I have a third party application that loads many css and javascript files, and I now want to optimize this by concatinating all the javascripts into one file, compressed by the yuicompressor, but ... when we have a mix like:
<script type="text/javascript" src="script1.js"></script>
<script type="text/javascript" src="script2.js"></script>
<link rel="stylesheet" href="style1.css" type="text/css" />
<script type="text/javascript" src="script3.js"></script>
<script type="text/javascript" src="script4.js"></script>
Does it matter that there's a css in the middle here? Should I concatinate and yuicompress the 4 javascripts and load them before the CSS or after?
Check out Yahoo's Best Practices for Speeding Up Your Web Site, they recommend loading your css first (preferably in the header), and your js last (after all the content in the body). Google's best practices also recommended loading CSS first.
It depends. If all the JS only works on DOM ready, the order is unimportant. However, if there is any in-line javascript that changes CSS styling of DOM elements, then you'll have issues.
More practically, you should probably put the CSS first so there is less time where the user needs to experience unstyled content.
It doesn't matter, although if loading takes a while, the user might see his page change appearance and wonder why. I'd put the CSS files first to have the style definitions in place before any DOM manipulation, most likely minimizing the visible change as the page loads, but it doesn't really matter in the end.