Categories
Original Tips

Change URL hash without page jump

In modern complex layouts, sometimes the point where a hash will transport you to will be entirely different than the one you actually wanted. If you prevent the default event, you will save yourself from the page jump, but the hash won’t change either. You can accept the regular behavior and change scrollTop after the jump, but the user will still see a distracting flicker.
Chris Coyier found a great workaround last year but it’s not meant for every case.

A different solution

Turns out we can take advantage of the History API to do that quite easily. It’s just one line of code:

history.pushState(null, null, '#myhash');

and we can combine it with the old method of setting location.hash to cater for older browsers as well:

if(history.pushState) {
    history.pushState(null, null, '#myhash');
}
else {
    location.hash = '#myhash';
}

Browser support?

The History API is supported by:

  • Firefox 4+
  • Safari 5+
  • Chrome 8+
  • Coming soon in Opera

Enjoy 🙂

Categories
Apps & scripts Original

StronglyTyped: A library for strongly typed properties & constants in JavaScript

StronglyTypedI’ll start by saying I love the loosely typed nature of JavaScript. When I had to work with strongly typed languages like Java, it always seemed like an unnecessary hassle. On the contrary, my boyfriend even though very proficient with HTML, CSS and SVG, comes from a strong Java background and hates loosely typed scripting languages. So, to tempt him into JS and keep him away from heavy abstractions like Objective-J, I wrote a little library that allows you to specify strongly typed properties (and since global variables are also properties of the window object, those as well) of various types (real JS types like Boolean, Number, String etc or even made up ones like Integer) and constants (final properties in Java). It uses ES5 getters and setters to do that and falls back to regular, loosely typed properties in non-supporting browsers.

Categories
Original Tips

Create complex RegExps more easily

When I was writing my linear-gradient() to -webkit-gradient() converter, I knew in advance that I would have to use a quite large regular expression to validate and parse the input. Such a regex would be incredibly hard to read and fix potential issues, so I tried to find a way to cut the process down in reusable parts.

Turns out JavaScript regular expression objects have a .source property that can be used in the RegExp constructor to create a new RegExp out of another one. So I wrote a new function that takes a string with identifiers for regexp replacements in {{ and }} and replaces them with the corresponding sub-regexps, taken from an object literal as a second argument:

/**
 * Create complex regexps in an easy to read way
 * @param str {String} Final regex with {{id}} for replacements
 * @param replacements {Object} Object with the replacements
 * @param flags {String} Just like the flags argument in the RegExp constructor
 */
RegExp.create = function(str, replacements, flags) {
	for(var id in replacements) {
		var replacement = replacements[id],
			idRegExp = RegExp('{{' + id + '}}', 'gi');

		if(replacement.source) {
			replacement = replacement.source.replace(/^\^|\$$/g, '');
		}

		// Don't add extra parentheses if they already exist
		str = str.replace(RegExp('\\(' + idRegExp.source + '\\)', 'gi'), '(' + replacement + ')');

		str = str.replace(idRegExp, '(?:' + replacement + ')');
	}

	return RegExp(str, flags);
};

If you don’t like adding a function to the RegExp object, you can name it however you want. Here’s how I used it for my linear-gradient() parser:

self.regex = {};

self.regex.number = /^-?[0-9]*\.?[0-9]+$/;
self.regex.keyword = /^(?:top\s+|bottom\s+)?(?:right|left)|(?:right\s+|left\s+)?(?:top|bottom)$/;

self.regex.direction = RegExp.create('^(?:{{keyword}}|{{number}}deg|0)$', {
	keyword: self.regex.keyword,
	number: self.regex.number 
});

self.regex.color = RegExp.create('(?:{{keyword}}|{{func}}|{{hex}})', {
	keyword: /^(?:red|tan|grey|gray|lime|navy|blue|teal|aqua|cyan|gold|peru|pink|plum|snow|[a-z]{5,20})$/,
	func: RegExp.create('^(?:rgb|hsl)a?\\((?:\\s*{{number}}%?\\s*,?\\s*){3,4}\\)$', {
		number: self.regex.number
	}),
	hex: /^#(?:[0-9a-f]{1,2}){3}$/
});

self.regex.percentage = RegExp.create('^(?:{{number}}%|0)$', {
	number: self.regex.number
});

self.regex.length = RegExp.create('{{number}}{{unit}}|0', {
	number: self.regex.number,
	unit: /%|px|mm|cm|in|em|rem|en|ex|ch|vm|vw|vh/
});

self.regex.colorStop = RegExp.create('{{color}}\\s*{{length}}?', {
	color: self.regex.color,
	length: self.regex.length
}, 'g');

self.regex.linearGradient = RegExp.create('^linear-gradient\\(\\s*(?:({{direction}})\\s*,)?\\s*({{colorstop}}\\s*(?:,\\s*{{colorstop}}\\s*)+)\\)$', {
	direction: self.regex.direction,
	colorStop: self.regex.colorStop
}, 'i');

(self in this case was a local variable, not the window object)

Categories
Original

Convert standard gradient syntax to -webkit-gradient and others

Screenshot of the demoI hate -webkit-gradient() with a passion. Its syntax is cumbersome and it’s really limited: No angle support, no <length>s in color stop positions, no implied color stop positions, no elliptical gradients… So, I was really happy, when Webkit implemented the standard syntax this January. However, we’re still stuck with the horrid -webkit-gradient() for quite a while, since older Webkit browsers that don’t support it are widely used at this time.

Today, I decided to finally spare myself the hassle of converting my standard gradient syntax to -webkit-gradient() by hand. Tasks like that shouldn’t be handled by a human. So, I coded a little script to do the chore. Hope it helps you too:
View demo

It currently only supports linear gradients, but I plan to add radial ones in the future. Also, when I get around to cleaning up the code a bit, I’ll add it on Github.

(Hope I didn’t leave in any very stupid bug, it’s really late here and I’m half asleep.)

Categories
Apps & scripts Original

Incrementable length values in text fields

I always loved that Firebug and Dragonfly feature that allows you to increment or decrement a <length> value by pressing the up and down keyboard arrows when the caret is over it. I wished my Front Trends slides supported it in the editable examples, it would make presenting so much easier. So, I decided to implement the functionality, to use it in my next talk.

If you still have no idea what I’m talking about, you can see a demo here:
View demo

You may configure it so that it only does that when modifiers (alt, ctrl and/or shift) are used by providing a second argument to the constructor and/or change the units supported by filling in the third argument. However, bear in mind that holding down the Shift key will make it increment by ±10 instead of ±1 and that’s not configurable (it would add too much unneeded complexity, I’m not even sure whether it’s a good idea to make the other thing configurable either).

You may download it or fork it from it’s Github repo.

And if you feel creative, you may improve it by fixing an Opera bug I gave up on: When the down arrow is pressed, the caret moves to the end of the string, despite the code telling it not to.

Categories
Tips

Reading cookies the regular expression way

While taking a look on the 2nd 24ways article for 2009, I was really surprised to read that “The Web Storage API is basically cookies on steroids, a unhealthy dosage of steroids. Cookies are always a pain to work with. First of all you have the problem of setting, changing and deleting them. Typically solved by Googling and blindly relying on PPK’s solution. (bold is mine)

Of course, there’s nothing wrong with PPK’s solution. It works just fine. However, I always thought his readCookie() function was too verbose and complicated for no reason. It’s a very common example of someone desperately trying to avoid using a regular expression. I googled for “javascript read cookie” and to my surprise, all examples found in the first results were very similar. I never understood why even experienced developers are so scared of regular expressions. Anyway, if anyone wants a shorter function to read a cookie, here’s what I use:

function readCookie(name) {
    // Escape regexp special characters (thanks kangax!)
    name = name.replace(/([.*+?^=!:${}()|[\]\/\\])/g, '\\$1');

    var regex = new RegExp('(?:^|;)\\s?' + name + '=(.*?)(?:;|$)','i'),
        match = document.cookie.match(regex);

    return match && unescape(match[1]); // thanks James!
}

Update: Function updated, see comments below.

I’ve been using it for years and it hasn’t let me down. 🙂

Probably lots of other people have come up and posted something similar before me (I was actually very surprised that something like this isn’t mainstream), but I’m posting it just in case. 🙂

Categories
Articles Original

Exploring browser-supported Unicode characters and a tweet shortening experiment

I recently wanted to post something on twitter that was just slightly over the 140 chars limit and I didn’t want to shorten it by cutting off characters (some lyrics from Pink Floyd’s “Hey You” that expressed a particular thought I had at the moment — it would be barbaric to alter Roger Waters’ lyrics in any way, wouldn’t it? ;-)). I always knew there were some ligatures and digraphs in the Unicode table, so I thought that these might be used to shorten tweets, not only that particular one of course, but any tweet. So I wrote a small script (warning: very rough around the edges) to explore the Unicode characters that browsers supported, find the replacement pairs and build the tweet shortening script (I even thought of a name for it: ligatweet, LOL I was never good at naming).

Categories
Original

A different approach to elastic textareas

I loved elastic textareas since the very first moment I used one (at facebook obviously). They let you save screen real estate while at the same time they are more comfortable for the end user. It’s one of the rare occasions when you can have your UI cake and eat it too!

However, I never liked the implementation of the feature. In case you never wondered how it’s done, let me explain it in a nutshell: All elastic textarea scripts (or at least all that I know of) create a hidden (actually, absolutely positioned and placed out of the browser window) div, copy some CSS properties from the textarea to it (usually padding, font-size, line-height, font-family, width and font-weight) and whenever the contents of the textarea change they copy them to the hidden div and measure it’s dimensions. It might be good enough for facebook, where the styling of those textareas is fairly simple and consistent throughout the site, or any other particular site, but as a generic solution? I never liked the idea.

Categories
Articles Tips

On password masking and usability

I just read Jakob Nielsen’s recent post in which he urged web designers/developers to stop password masking due to it’s inherent usability issues. I found it an interesting read. Hey, at last, someone dared to talk about the elephant in the room!

In most cases password masking is indeed useless, but still, there are several cases where you need that kind of protection. He also points that out, suggesting a checkbox to enable the user to mask their entered password if they wish to do so. He also suggests that checkbox being enabled by default on sites that require high security.

I think the checkbox idea is really good, as long as it works in the opposite way: Password masking should always be the default and you should check the checkbox to show the characters you typed. This is in line with what Windows (Vista or newer) users are already accustomed to anyway

Categories
Apps & scripts Original

Cross-browser imageless linear gradients v2

A while ago, I posted a script of mine for creating 2-color cross-browser imageless linear gradients. As I stated there, I needed them for a color picker I have to create. And even though 2-color gradients are sufficient for most components, in most color spaces, I had forgotten an important one: Hue. You can’t represent Hue with a 2-color gradient! So, I had to revise the script, and make it able to produce linear gradients of more than 2 colors. Furthermore, I needed to be able to specify a fully transparent color as one of the gradient colors, in order to create the photoshop-like 2d plane used by the picker (and no, a static image background like the one used in most JS color pickers wouldn’t suffice, for reasons irrelevant with this post). I hereby present you Cross-browser, imageless, linear gradients v2!