Articles

3 ways to check if object do not contains any properties (is “empty”)

During some tests I found at least 3 ways to check if object “is empty”. I mean, do not contains any enumerable properties. Assuming we have an object:

var obj = {};

Then we can use:

if(JSON.stringify(obj) == '{}'){
    // object is "empty"
}

or

if(Object.keys(obj).length == 0){
    // object is "empty"
}

or

var isObjectEmpty = function (obj) {
    for (var key in obj) {
        if (Object.prototype.hasOwnProperty.call(obj, key)) {
            return false;
        }
    }
    return true;
};

if(isObjectEmpty([......]

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Don’t forget about “Expires” header

Why use Expires header?

Expires header tell the browser whether a resource needs to be requested from the source (server), or if it can be fetched from the browser’s cache. When we set an Expires header for a resource, such as all images, JavaScript files, or CSS, or whatever file we want, the browser will store those resources in its cache. The next time the visitor comes back to the page it will load faster, as the browser will already have those contents available in its cache, and will not need to download them from the server.

Benefi[……]

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There is No Right Way to Develop Software

I like it:

Being a good developer means compromise. It means sometimes doing things one way for one project, and another way for another. It means balancing the needs of your stakeholders with your ideals. Sometimes they’re not always going to match up, but that doesn’t mean you should stomp the ground with your feet and have a tantrum when things don’t go your way.

The real key? Strong opinions, weakly held.

With that alone, you’ll go far.

Source: dlo.me

[……]

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Internet traffic control and monitoring tool

Sometimes our network connection is too fast for measure eg. “how my website is loaded”. In that case would be good to slow down our download / upload connection and test our loading website using slower connection. I use NetLimiter – Ultimate Bandwidth Shaper which provide me option for download and upload streaming.

Note: above software is designed only for Windows OS.[……]

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Moving jQuery and other script code to the bottom of html code in Worpdress

Why script (eg. JavaScript) needs to be put at the bottom of html code is nicely described in article High Performance Web Sites: Rule 6 – Move Scripts to the Bottom. So now I will not explain here why.

Let’s focus on how to move any scripts in WordPress to the bottom of html code. Let’s say we want to move mycode.js file (which is located in /js/ directory in our theme directory) with our code that depend on jQuery in our WordPress theme. Open header.php and insert the code just before any html code:


and also in footer.php just befor[……]

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Apache and error AH00132

Let’s say you have a localhost (based for example on Wamp) on your computer where is Windows OS. You may be surprised that sometimes some files you can not run. In “error console” of Apache you may see error AH00132 which can look like this:

[Fri Mar 15 17:44:24.195510 2013] [core:error] [pid 6236:tid 1040] (OS 5) Access denied. : [client 127.0.0.1:51288] AH00132: file permissions deny server access: C:/wamp/www/test/index.html

Well, the problem is in the option “Encrypt contents to secure data” which was set for directory “test“. The[……]

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font-face and aborted request(s)

By default at least IE up to 9 8 (not tested on IE10 IE 9 and 10 doesn’t block loading content and they use local fonts, if available) blocks loading page until fonts are not downloaded. Moving fonts for font-face to separate subdomain (eg. fonts.example.com) means that page loading will not be blocked by loading fonts from font-face. However, you may discover that fonts are not loaded after moving them to separate subdomain. What is wrong?

You must add header Access-Control-Allow-Origin "*" (or specify here your subdomain) when serve fonts[……]

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Detect browser cookie third party support using feature detection

So, you want to detect browser cookie third party support.

What is third-party cookies

Basically, third-party cookies are cookies that are set by a website other than the one you are currently on. For example, ctomczyk.pl might have a Twitter like button. That button will set a cookie that can be read by Twitter. That would be considered a third-party cookie.

Some browsers (from specific versions), like Firefox and Safari, have this option disabled by default. However, see page “How to enable third-party cookies in your web browser” t[……]

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Loading optimization tips

Your web page / application loading very slowly? There is several reasons why your data is loading slowly. However, some tricks can be done to make load site faster.

Max connections per hostname

Try to measure amount of connections using Firebug in Firefox console, also in Google Chrome, Opera or Internet Explorer. There is also nice tool named “HTTP Analyzer” (30 days of trial) which can help you track the network connections. Even, if they are not coming from browsers only.

Every browser can open some several connections per hostname[……]

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