php – computeraxe

How to Change the Format of MySQL Dates Using PHP

Dates stored in MySQL databases are represented using the format ‘YYYY-MM-DD’. People don’t usually say they accomplished a task on 2013-01-01, so this format is not the most convenient. Often we need to convert the format of a date stored in a database into a more readable or more user-friendly format.

We can use PHP to re-format dates retrieved from a MySQL database using two functions, DateTime() and date_format().

Note: One requirement for the DateTime() function to work is that the date column in the database must be of the type datetime, not date. Even if the date column started life with the type date, it can be changed at any time. Just realize that dates will now be reported along with the time, which will be all zeroes in this case. To make the date look pretty again, use both functions as outlined below.

A warning is reported when a date column is of the type date when a function expects the type datetime. You might see something like “Warning: date_format() expects parameter 1 to be DateTime, string given” if this happens to you.

Once the dates are recorded as the type datetime, using the date_format() function of PHP will work. Going back to values that are already stored in a database and updating the type is ok, this doesn’t have to happen at the creation of the database. So, if you’re keeping track of dates and want to use a format other than something like “2013-01-01”, keep reading. Continue reading How to Change the Format of MySQL Dates Using PHP

Learning Code Resources to Beat the Summer Heat

People love the summertime with all its heat and sunshine. But not everyone likes to bask in the sun, so instead they turn to cooler activities than baking their skin to a crisp. Count me in as one of those people who hibernate away from the heat or in a word, estivate.

What can we do to avoid the scorching sun in the middle of the day? We could take a nap to avoid the heat, or go to a movie or take the time to learn something cool. How about learning to code? It’s not that hard to pick up a new tip or trick, you just have to want to. With that, here’s a few resources to get you started on your way to learning something new this summer.

Free Online Learning Tools

CodeAcademy– sign up for an account to track your progress
CourseHero– check out the Web Programming path
W3Schools– complete with references, quizzes, examples and a certification path

Need more? Take a look at this great list of online learning centers.

Putting Readable Code in a WordPress Post

Writing about PHP or HTML code in WordPress posts or pages often requires that some actual code is shown on the screen for explanation. If special steps aren’t taken to illustrate the code as text, the result is often not what was intended to be seen because the WordPress engine will interpret the code as actual code, not text about code.

If all you want to do is highlight some text that includes code-related words like filenames, function names or plugin names, use <code></code> around those phrases in your text. Using <code></code> turns text into a monospaced font so that it appears differently in your posts than “normal” text. However, using <code></code> around an HTML tag doesn’t do anything except change the presentation of the tag, so the opening and closing angle brackets are interpreted to enclose an actual HTML tag. The result will be a mess and definitely not what you were hoping to see.

To make WordPress show code in a post without interpreting it, you have to do ONE of three things:

Use special character codes to replace angle brackets of tags.
Use the HTML tag <pre></pre> around the code.
Use a plugin to highlight the code syntax.

1. Special Character Codes

Angle brackets, < or >, are what WordPress uses to identify code, whether it’s HTML, inline styles of CSS, or PHP. Content inside angle brackets is interpreted as code by virtue of placement inside the brackets. Instead of interpreting this code we want WordPress to show the code to the site visitors and we can use special character codes to do that.

Character codes are special sequences of letters or digits that are used to represent textual characters. Every character that we see on the screen, including uppercase letters, lowercase letters, numbers, and symbols like <, >, #, $, %, ^, & or *, can be represented by character codes, sometimes called character entities.

Using character codes in posts looks a little strange in the editing panel, but when a browser comes across these codes they are interpreted and their textual equivalent is shown on the screen.

ASCII (American Standard Code for Information Interchange) character codes were developed to represent text in electronic devices and they follow a specific format. The format is that each character entity starts with an ampersand and ends with a semi-colon. The codes are a couple to a few letters or numbers. Numbered character codes always have a hash symbol right after the opening ampersand. Some entities can be represented by either numbered or named codes.

Examples of special character codes:

Character name	Character symbol	Character ASCII Code
left angle bracket	<	<
right angle bracket	>	>
ampersand	&	&
dollar sign	$	$
long dash	—	—
short dash	–	–
double quotes	"	"
at sign	@	@

If you need to find a code for language sets other than English, try the unicode site for all the code charts you’ll ever need. There, you can find numeric codes for fun game pieces, like chess, mahjong or checkers, horoscope symbols, smiley faces, weather symbols, music notes, and much more.

Take caution: Just because you can enter a special code to represent a symbol, that doesn’t mean your computer will let you see it. Many operating systems will not have the proper fonts installed to make use of all of these codes, especially if they represent symbols that aren’t on your keyboard. Stick to the ASCII codes as many of the unicodes won’t be seen by your site visitors.

2. HTML tag: <pre>

Perhaps you’d like to show a block of HTML code on your post and have it shown as text. To make sure that your block of code is not interpreted as actual code, wrap it with <pre></pre> tags. The <pre> tag will change the appearance of the code into a monospace font, just like <code> does, but the difference is that <pre> also illustrates the code exactly as it was typed. All text, characters, spaces and line feeds will be reproduced exactly how they were entered. No code will be run when it’s protected inside the opening <pre> and closing </pre> tags.

3. Syntax Highlighter Plugins

A final way to illustrate code in a WordPress post or page is to use a plugin to highlight the code. Several plugins are available for syntax highlighting purposes.

One that I have been using lately is called Crayon Syntax Highlighter. It’s a great plugin that will colorize or highlight code that you wrap with shortcodes. There are lots of options if you want fine control over the color scheme. Themes come with the plugin so you have several choices for making your code look good.

There are two modes where you can highlight code differently using shortcodes, [crayon][/crayon] and [plain][/plain]. Use [plain] shortcodes when the colorized crayon is overkill or when you just want to show a small section of code. Crayon Syntax Highlighter supports a wide range of languages, including HTML, CSS, PHP and JavaScript, for starters.

The colorful [crayon] shortcode is controlled by options where you can pick the colors that you want for representing different sections or purposes in your code. Inline crayons are supported so you could put a line of code within a line of text and the code would be colorized.

Some other popular code-highlighting plugins include SyntaxHighlighter Evolved, WP-Syntax, and CodeColorer. I don’t have any personal experience with these plugins, but they are listed high in popularity at the WordPress Plugin Directory.

Need to Execute Code in a Post?

If what you’re really after is to put executable code in a post or WordPress Page, check out this post on executing PHP in WordPress blogs.

Loading WordPress with One jQuery

If there are several plugins on your WordPress sites there may be more than one copy of jQuery, or other script, that’s loaded, especially if you’re relying on the same scripts for control of the site theme as well. Only one copy of each script should be loading up. More than that represents wasted bandwidth for you and wasted time for your site visitors.

To control what scripts are used on your site it may be wise to learn how to disable scripts from loading in the first place. Similar methods can be applied to streamline the number of scripts or stylesheets loaded onto your site.

Check out this great tutorial on disabling scripts and styles. Thanks for sharing, Justin!

You’ll need to modify the functions.php file of your theme to remove styles or scripts. The technique is similar in each case.

Find the ‘handle’ of the script that you’d like to remove.
Pass the script handle to wp_deregister_script().
Wrap one or more ‘deregistrations’ in a new function, like my_deregister_javascript() in this example.
Use add_action() with wp_print_scripts method and add your new function to the functions.php file of your theme.

[plain]
function my_deregister_javascript() {
wp_deregister_script(‘jquery-form’);
}
add_action(‘wp_print_scripts’, ‘my_deregister_javascript’);
[/plain]

From the reference on add_action in the WordPress codex we can see that two arguments are required, namely the $tag or handle of the script and the $function_to_add or the function to which the script is hooked. Two optional parameters can be added to the add_action function to specify the $priority or the order in which the functions are executed, and $accepted_args or the number of arguments that the function accepts. Generically,

[plain]
add_action( $tag, $function_to_add, $priority, $accepted_args );
[/plain]

In the example above we’ve used ‘wp_print_scripts’ for $tag and ‘my_deregister_javascript’ for $function_to_add while the optional $priority and $accepted_args were not used. This will hook the new function ‘my_deregister_javascript’ to the action called ‘wp_print_scripts’.

Alternatively, a WordPress plugin could be used to manage the scripts and actions called for on your site. Use Google Libraries is a plugin built to detect the scripts needed for a site to run properly, including all the scripts called for by plugins and the active theme. Scripts are loaded in the proper order taking into account dependencies, whether previously known to WordPress or whether provided by the plugin and theme authors. This plugin uses the content delivery network (CDN) of google to supply the most popular javascript libraries, including jQuery and jQuery UI, among others.