PHP

Filters are used in Drupal to change the content of the text of a node when it is viewed. The important thing to note is that Drupal filters should never alter the actual content of the node itself. Instead, when a node is saved it stores the output of the filter in the cache_filter table and displays this content the next time the node is viewed. This is useful because it doesn't mess about with the original text, and it speeds up the displaying of the node by running the filters once, rather than every time the node is loaded.

However, there is one thing that you should watch out for when creating your own modules. If you are using any data from other tables in your filters then you will need to clear the cache when this data changes.

There are a few URL shortening services about, of which bit.ly is just one. However, it does provide a nice API for developers to interact with the site. Not only is it possible to shorten URL's, you can also reverse them, find out information about the site and get information about how many people have used to link. The API requires you to create an account to interact with the API. Once you have created an account you can use the API service.

Download the bitly API interaction PHP class.

There are several functions available in this class but the main two are shorten() to turn a URL into its bit.ly equivalent and expand(), which will do the exact opposite.

To convert a URL into its bit.ly equivalent you can call the shorten() function like this.

The usual practice when checking for the return value of functions is to run the function and store the value in a variable, and then test that variable. Here is an example of that process using the strstr() function.

$string = 'abcde';
$var = strstr($string, 'f');
if ( false !==  $var ) {
    var_dump($var);
} else {
    var_dump($var);
}

This code will output "bool(false)" as that was the return value of the strstr() function.

If you want to incorporate a W3C validation check into an application then you can use the following class. It uses file_get_contents() to get the contents of the file and then uses regular expressions to return either the number of errors or -1 is any errors occur. Of course if the document is valid the function will return 0.

TinyURL is a service where you can convert a long URL string to a really small one. For instance, the following URL, which points to the Googleplex on Google Maps.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=googleplex&sll=37.579413,-95.712891&sspn=34.512672,45.615234&ie=UTF8&cd=1&z=16

Can be converted to the following.

http://tinyurl.com/qpkor2

This is perfect for posting to Twitter or similar microblogging platforms as it saves lots of character space.

This is quite a simple thing to do and it is quite easy to add a little link to your Wordpress posts. If the user is logged into Twitter on the web (which isn't all that common with multiple Twitter apps taking over) then when they click on a link they will be taken to their Twitter profile and their status box will contain the text you have set. You won't actually be able to update a users status for them, they have the final control over that, but some users will update their status so it is worth doing.

This is all done through a URL using the status parameter, like this.

http://twitter.com/home/?status=text+to+post

Because this is a URL you will need to encode it properly in order for Twitter to understand it. Using Wordpress you need to put a call to the urlencode() function to encode any string you might want to post.

If you are constructing a simple string from a set of variables contained in an array then you can use the implode function to convert the array into a string. The implode() function takes two parameters. The first is the glue that is used to join the items in array together and the second is the array to use. Here is a trivial example of implode() in action.

$array = array(1, 2, 3, 4, 5, 6);
 
echo implode(',', $array);

This will print out the following:

1,2,3,4,5,6

The good thing about the implode() function is that it doesn't add stray commas to the start and end of the string so there is no need to alter the string after the function is used.

The other day I needed to hide an image but keep the original image intact so rather than do complicated things with light and dark filters I decided the best way would be to pixelate the image. All that is required to pixelate an image is to shrink it down and then blow it up to the original size, thus reducing the quality of the image.

The following code will do this process for a jpeg image. The pixelate amount variable is used to reduce the width and height of the first image using division and then multiply them back again to the original values for the output image. Remember to change the ImageCreateFromJPEG() to the format you want.

Zend_Search_Lucene offers some powerful document scanning capabilities, and there are a few different formats that are useful for the search engine to index.

To allow the indexing and searching of Excel documents using Zend_Search_Lucene you need to use the Zend_Search_Lucene_Document_Xlsx class. However, to use this class you must have the Zip module installed with PHP. For Windows users this means editing your php.ini file and uncommenting the following line:

extension=php_zip.dll

For Linux users you will need to recompile PHP with the --enable-zip configure option.

Create and/or open the index in the normal way and you can index Excel documents using the following code.

Multi pages forms are just as they sound, a single form spread across multiple pages. These are useful in terms of usability as it can break up an otherwise dauntingly big form into smaller chunks. It can also be useful if you want to process some of the results in order to determine what forms the user sees on later steps.

There are two ways in which it is possible to do this using PHP.

The first (and simplest) is just to cycle through the items submitted on a previous form and print them out as hidden fields. Our first page source code will look like this: