Decoupling presentation from content

Box model in CSS
Box model in CSS (credit: Wikipedia)

I recently ran across the anti-pattern of what I see as a common problem amongst designers and developers: coupled presentation and content. I’ve found that decoupling the presentation from the content makes things much easier to write, maintain and expand.

Here’s a simple example:

HTML

<section>
    <div class="margin-top-10">Lorem Ipsum</div>
</section>

CSS

.margin-top-10 { margin-top: 10px };
.margin-top-20 { margin-top: 20px };
(etc)

Take a look at what is going on here: we’re adding a 10px margin to the top of the div. DON’T DO THIS. You want your class names to be contextual, not descriptive of the style.


Rule of thumb

To change the layout, you should only have to edit the CSS, not the HTML.

Here’s where our anti-pattern falls down and will cause grief.

  1. You decide to adjust the positioning of the section. You can:
    • Edit the CSS, changing the class’s margin value and breaking every other element that uses that class.
    • Edit the HTML create a new class, then edit its CSS class definition. If you have to experiment with different margin values, you’ll need a LOT of classes. “Will 14px work or 15px? What about .25em? Argh!”
  2. You can’t have too many attributes in each class, because they will have unintended consequences for the other elements that are using them. Add a red border to one class because you need a border for a specific element, now you have red borders on ALL the elements that share that class. So, you’ll have to have many single- (or few-) attribute values, and include all of the necessary ones on the required HTML elements.
  3. The violent psychopath maintenance programmer (who knows where you live) will kill you in your sleep. You have made her job insanely hard by turning this:
<div class="margin5 blueborder mediumwidth floatingleft" ...

into this

<div style="margin:5px;border:3px blue outset;float:left;width:75%" ...

for no good reason.

The Cure

Think about the element in terms of content or a functional space. What is it and what does it do? In our example above, let’s assume it is the lede section of an article. Then we would do:

HTML

<section>
    <div class="lede">Lorem Ipsum</div>
</section>

CSS

.lede { 
  margin-top: 10px;
  border-bottom: 2px #9fe2f9 outset;
  float: right;
  position: relative;
  width: ...
};

By decoupling the content (div) from the presentation (style-dependent class), we are free  to adjust the style of that element by making whatever changes to the CSS and leaving the HTML alone.

“But,” you shriek, “I have common elements for everything! Rounded corners! Gradients! (except IE…) Et cetera!”

 

For this, we will turn to our trusty companions Less and/or Sass in a future post.

SASS: Style w/ Attitude
SASS: Style w/ Attitude
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Iterations in Less

Part of the beauty of Less and other CSS ‘compilers’ is to enable the author to automate tedious functions that normally must be coded by hand.

Cut Copy Paste
Cut Copy Paste (Photo credit: arthit)

Suppose you needed several classes that specified padding/margins:

.mRight50{margin-right:50px}
.mLeft50{margin-left:50px}
.pRight50{padding-right:50px}
.pLeft50{padding-left:50px}
.mRight25{margin-right:25px}
.mLeft25{margin-left:25px}
.pRight25{padding-right:25px}
.pLeft25{padding-left:25px}

No big deal, right? It wouldn’t take that long to type in; just cut and paste a bit.

Well, what if you needed them from 0-100 by 5s? (Never mind WHY you’d want to do this; this is a simple example.)

.mRight100{margin-right:100px}
.mLeft100{margin-left:100px}
.pRight100{padding-right:100px}
.pLeft100{padding-left:100px}
.mRight95{margin-right:95px}
.mLeft95{margin-left:95px}
.pRight95{padding-right:95px}
.pLeft95{padding-left:95px}
.mRight90{margin-right:90px}
.mLeft90{margin-left:90px}
.pRight90{padding-right:90px}
.pLeft90{padding-left:90px}
.mRight85{margin-right:85px}
.mLeft85{margin-left:85px}
.pRight85{padding-right:85px}
.pLeft85{padding-left:85px}
.mRight80{margin-right:80px}
.mLeft80{margin-left:80px}
.pRight80{padding-right:80px}
.pLeft80{padding-left:80px}
.mRight75{margin-right:75px}
.mLeft75{margin-left:75px}
.pRight75{padding-right:75px}
.pLeft75{padding-left:75px}
.mRight70{margin-right:70px}
.mLeft70{margin-left:70px}
.pRight70{padding-right:70px}
.pLeft70{padding-left:70px}
.mRight65{margin-right:65px}
.mLeft65{margin-left:65px}
.pRight65{padding-right:65px}
.pLeft65{padding-left:65px}
.mRight60{margin-right:60px}
.mLeft60{margin-left:60px}
.pRight60{padding-right:60px}
.pLeft60{padding-left:60px}
.mRight55{margin-right:55px}
.mLeft55{margin-left:55px}
.pRight55{padding-right:55px}
.pLeft55{padding-left:55px}
...

Ugh.

There’s a better way:


@steps: 100;

// Main Loop
.sidesX( @index ) when ( @index > 0 ) {
 (~".mRight@{index}") { .mRightX(@index); }
 (~".mLeft@{index}") { .mLeftX(@index); }
 (~".pRight@{index}") { .pRightX(@index); }
 (~".pLeft@{index}") { .pLeftX(@index); }

 .sidesX(@index - 5);
}

// End iteration at index zero
.sidesX( 0 ) {}<

// Individual class rendering
.mRightX( @offsetsize ) {
  margin-right: (~"@{offsetsize}px");
}
.mLeftX( @offsetsize ) {
 margin-left: (~"@{offsetsize}px");
}
.pRightX( @offsetsize ) {
 padding-right: (~"@{offsetsize}px");
}
.pLeftX( @offsetsize ) {
 padding-left: (~"@{offsetsize}px");
}

// Generate the CSS
.sidesX( @steps );
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Flashback: Skip Intro for flash introductions

Remember when flash introduction pages were all the rage? They were ‘cool’ from the web designer‘s standpoint, but utterly annoying and off-putting to the visitor. Fortunately, most people figured out that people visited their site for the content, not the snappy graphics (unless it was a gallery site), and certainly not for the mandatory intro pages.

Yet, some people still haven’t gotten the clue that the 80s called and they want their flash intros back.

xkcd: the seventies called

For those who remember with revulsion, here’s the old SkipIntro parody. The site is long gone, but it would be a shame to let it fade away!

SkipIntro

(click the ‘play ball’ to start)

Get Adobe Flash player

If you haven’t clicked on it, do it now! Relive the pain of the never-ending flash intro to the sound of weird indian music and gunfire!

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Regular Expressions Roundup

Writing some Regular Expressions?

Some people, when confronted with a problem, think “I know, I’ll use regular expressions.” Now they have two problems.
—Jamie Zawinski

Well, not really. There are some cases where using a Regular Expression—RegEx— instead of a heap of convoluted if statements just makes sense from both a lazy and practical standpoint.

When you’re knee-deep in writing your RegEx, you’ll need to test. My favorite RegEx ‘workbench’ is Oliver Steele’s “reWork.”

screenshot of reWork

To get a jumpstart on writing complex RegEx,  check out the Regular Expression Library, which contains a plethora of user-submitted RegEx recipes. Some of them are quite good (check each recipe’s rating).

screenshot of example page

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Find Something You Like and Dissect It

Image representing Wikipedia as depicted in Cr...
Image via CrunchBase

I’m always on the lookout for a new technique or Better Mousetrap. I admit I don’t know all that much, so I’m happy to learn.

I was playing around with Wikify @ appointment.net (a nifty tool that goes through a block of text and ‘wikifies’ it–that is, links all the words it can find to relavant Wikipedia articles) when I noticed the behavior seemed rather…odd. I could see it go through the word list as it created links, and every time it linked up a word, every duplicate word was linked.

Let’s take some example text (from the now-defunct Dilbert Mission Statement Generator) and run it through the site:

“We have committed to synergistically fashion high-quality products so that we may collaboratively provide access to inexpensive leadership skills in order to solve business problems

Our mission is to continually leverage existing seven-habits-conforming catalysts for change as well as to competently leverage other’s error-free materials.

We globally leverage other’s professional meta-services as well as to conveniently integrate competitive solutions in order to solve business problems.

“It is our job to continually foster world-class infrastructures as well as to quickly create principle-centered sources to meet our customers needs

“Our challenge is to assertively network economically sound methods of empowerment so that we may continually negotiate performance based infrastructures

For example, the additional instances of “leverage,” “problems,” and “business” were quickly linked, once the first one was completed. Poking around their code, I noticed all the action takes place in wikify.js. There are a few gems in there. For example, the function call to reduce an array to only unique values:

function array_unique( array ) {
    // http://kevin.vanzonneveld.net
    // +   original by: Carlos R. L. Rodrigues (http://www.jsfromhell.com)
    // +      input by: duncan
    // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   bugfixed by: Nate
    // +      input by: Brett Zamir (http://brettz9.blogspot.com)
    // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: Michael Grier
  // %          note 1: the second argument, sort_flags is not implemented
    // *     example 1: array_unique(['Kevin','Kevin','van','Zonneveld','Kevin']);
    // *     returns 1: ['Kevin','van','Zonneveld']
    // *     example 2: array_unique({'a': 'green', 0: 'red', 'b': 'green', 1: 'blue', 2: 'red'});
    // *     returns 2: {'a': 'green', 0: 'red', 1: 'blue'}

    var key = '', tmp_arr1 = {}, tmp_arr2 = [];
    var val = '';
    tmp_arr1 = array;

    var __array_search = function (needle, haystack) {
        var fkey = '';
        for (fkey in haystack) {
            if ((haystack[fkey] + '') === (needle + '')) {
                return fkey;
            }
        }
        return false;
    };

    for (key in tmp_arr1) {
        val = tmp_arr1[key];
        if (false === __array_search(val, tmp_arr2)) {
            tmp_arr2[key] = val;
        }
        delete tmp_arr1[key];
    }
    return tmp_arr2;
}

Aha! See how that works?

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The Importance of Not “Designing” your own Security

Recently, at a client, I had the opportunity to review their security implementation on their website. I realized that it is very important to never try to design one’s own security, because of the Dunning Kruger effect. In a nutshell, folks who don’t know very much about security think they know “enough,” and folks who are very knowledgable (e.g., Bruce Schneier) realize they don’t know all that much.

So what does this mean? It means simply this:

If you design your own security system, you’re going to get it wrong.

English: A Master padlock with "r00t"...
(Photo credit: Wikipedia)

Here are some examples of how to get things wrong.

Storing passwords in plaintext so you can send the person the password if they forget.
When (not if) someone breaks into your database, they instantly own every single account. They can log in, view your user’s details and change them. Since most people reuse the same password for multiple systems, the attacker can try those passwords on other popular services, such as Facebook, GMail, LinkedIn, Twitter, etc.
Relying on application-level security to protect your data.
This is dangerous because it is hard to ensure 100% coverage. EVERY access point—of many—to your data must be secure. Failing to cover one point leaves the system wide open. A better solution is to apply security at the data-store level. Typically, this is done using triggers and stored procedures. Your RDBMS doesn’t support those (or weakly supports them)? Find another RDBMS.
Using the same salt for every password in the system.
You don’t understand what salts are for and how to use them properly.
Requiring “complex” (a number, upper- and lower-case letters and symbols but not very long) passwords.
Nope. Ineffective.
Relying on Two-Factor Authentication.
For now it is working, somewhat, but crackers are rapidly finding ways to circumvent this technique.
Relying on a “security question” in case the person forgets his/her password.
Oh, you’ll love this. You’re creating a weak password as a backup to a (hopefully) strong password. Fail.
Assuming by keeping the details of your implementation secret, you will be secure.
This is dangerous because you think you’re secure. In fact, you are less secure. Kerckhoffs’s Principle is always a good starting point for security implementation: if an attacker could see all of my code and had a copy of my database, could she/he break into my system?

Getting it right

The first step is admitting that you don’t know what you’re doing.

Now go find someone who does: there are plenty of security libraries out there for every language. Find one that is mature and widely used and implement it. Keep up to date on the library’s mailing list so you will receive alerts, and update whenever there’s a new version.

Security is hard to do. It is extremely hard to do correctly. Don’t fall into the trap of thinking you can get it right without years and years of study and experience.

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Wicked Cool FizzBuzz in Perl

The FizzBuzz problem is a simple coding demonstration to write an application in any language that counts from 1 to 100:

Write a program that prints the numbers from 1 to 100. But for multiples of three print “Fizz” instead of the number and for the multiples of five print “Buzz”. For numbers which are multiples of both three and five print “FizzBuzz”.

I found the following on Stackprinter (deleted Stackoverflow questions) by  “ysth”; probably the best example of wicked-cool code obsfucation, ever.

(                       (
''))=~('('.'?'.'{'.("`"|
'%').('['^'-').('`'|'!').
('`'|',').'"'.('['^'+').(
         ((            (
         (             ((
         (             ((
         '['         ))))
          )))))^(')')).(
           '`'|")").(
         (              (
         '`'))|'.').('['^
         '/').'+'.('(').(
         '`'^'&').(('`')|
                     ((
                      ((
                    ')'))
                   ))).+(
                   "["^

         (              (
         '!'))).('['^'!')    .')'
         .'['.''.('$').    '_'.
         '%'.('^'^(('`')|     ((
         (              (
         '-')))))).(']').
         '.'.'('.('`'^'"'
         ).('['^'.').('['
                       ^
                       ((
                       ((
         '!'))))).(('[')^
         '!').')'.('[').
         ''.'$'.'_'
                        .
            '%'.('^'^('`'|'+'
         )).']'.'|'.'|'.''.
         '$'.'_'.','.''.'$'
         .+             (
         ((
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            '/')))))))).(
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                   '`')))|
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         ^('`'|'/'         )).".".
         ((                      '.'

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         .                         (
         '^'^('`'|'/')).('^'^(('`')|
         '.')).('^'^('`'|'.')).('!'^
         (              (          (
         (              (          (
                        (          (
                        (          (
                       '+'         )
                      )))))        )
                                   )
                                  ))
                               ).'"'

         .              (
         '}').')');$:='.'    ^'~'
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               '`'|'.';$,='('

                   ^'}';$
              ='`'|'!';$:=")"^
           '}';$~='*'|'`';$^="+"^
         ('_');$/=         '&'|'@';
         $,                      =((

           (             "[")))&
          ((           ('~')));$=
         ((           ','))^    '|'
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        '.'))^'~';$~='@'|'(';$^=")"^
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         )                  )))
         )     )              ;$/
          ='&'|                  '@'

          ;$,                    =
         '['                     &+
         ((                       ((
         (                         (
         (                         (
         (             ((          (
         '~'         ))))))      )))
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          $:='.'^"~";    $~="@"|
            "(";$^=

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          |+
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         |
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          ((
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          $:
         )=((
         ')')

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         '}');$~='*'|'`';$^="+"^
         '_';$/='&'|'@';$,='['&'~'
         ;
         (
                  $)=","^
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           '@'|'(';$^=')'^'[';$/=
          "`"|               ".";
         $,                       =(
         (                         (
         (                         (
         ((                      '('
          )))))               ))^((
           '}'));$='`'|('!');$:=
              ')'^'}';$~="*"|

                  ('`');$^=
             '+'^'_';$/='&'|'@'
           ;$,='['&'~';$=','^'|'
          ;($:)               ='.'^
         ((                       ((
         (                         (
         (                         (
         ((                      '~'
          )))))               )))))
           ;$~='@'|'(';$^=')'^'['
              ;$/='`'|".";#;#

Save the above Asciiart into a file called, for example, fizz.pl.

Then run it: perl fizz.pl

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Bulk fix a list of words to the proper case

A set of metal types
A set of metal types (Photo credit: Wikipedia)

Problem

Given a long list of upper-case words (one word per line), such as:

MARY
JOE
SCOTT
FRED
... (for thousands of rows) ...

You want to change this to

Mary
Joe
Scott
Fred
(etc)

Solution

Perl
Perl (Photo credit: Wikipedia)

Use perl from the command line. Assume all your names are in a file called ‘names.txt’. We’re going to send the output to a new file called ‘cap_names.txt’.

$ perl -pe 's/^(.)(.*)$/1L2/g' names.txt > cap_names.txt

How this works

On the matching side:
^(.) → get the first character. The parenthesis allow us to refer to it as 1.

(.*)$ → get the rest of the line. The parenthesis allow us to refer to it as 2.

On the substitution side:

1 → outputs that first character, as is.

L2 → outputs everything else, lower case (the L makes everything in 2 lower case).

Neat!

Inspired by Regexident’s answer at StackOverflow.

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Don’t Call Yourself A Programmer

I’ve always hated the term “Programmer.” Like a craftsman, I’m a Developer.

Patrick McKenzie has a great writeup on this:

Engineers are hired to create business value, not to program things: Businesses do things for irrational and political reasons all the time (see below), but in the main they converge on doing things which increase revenue or reduce costs.

Producing beautiful software is not a goal. Solving complex technical problems is not a goal. Writing bug-free code is not a goal. Using sexy programming languages is not a goal. Add revenue. Reduce costs. Those are your only goals.

I’ll add that adding perceived business value is also a goal (playing off McKenzie’s “Businesses do things for irrational…reasons”). If your boss feels happy, then you’re doing the right thing. Most of the time.

Where we run into trouble is when the boss is a micro-manager, is inexperienced and/or plain-ol-wrong. What do you do? As a professional, speak up and say what’s on your mind, diplomatically. Then do whatever the boss says, cheerfully.

Is this always the best solution? Sometimes it is and sometimes it is not. The boss that thinks for his employees is doing exactly the wrong thing, though:

by Kathy Sierra
“The more you use the reins, the less they’ll use their brains.”

What are your top commands?

Sometimes it is interesting to navel-graze. What commands do you type the most?

history | awk '{a[$2]++}END{for(i in a){print a[i] " " i}}' | sort -rn | head

Here’s mine:

95 ll
93 git
67 cd
37 vi
29 identify
15 find
12 agvtool
11 history
11 exit
10 cat

“ll” is an alias for ls -l
Interesting that I’ve been using imagemagick (identify) a lot. I’ve been formatting/sizing a bunch of images for inclusion in an iOS app, so that’s probably what that is from.