Drupal 7 Module Development

Chapter 11
In order to open files from remote locations, PHP must have the allow_
url_fopen setting enabled in your php.ini. For more information see:
http://us2.php.net/manual/en/filesystem.configuration.
php#ini.allow-url-fopen
This is pretty straightforward. Using the PHP function file_get_contents(),
we grab an image of Drupal's mascot, the Druplicon, and save it into the variable
$image. We then save it locally using the Drupal API function file_save_data(),
which returns a file object file_save_data(), and takes three arguments. The first
argument is the contents of the file, as a string. file_get_contents() returns a
string, so this works out well.
The second argument specifies the location where the file should be saved. This
destination should be represented as a URI, using one of the system's registered
stream wrappers. We will discuss stream wrappers in more detail later in the
chapter, but for now, just know that you can refer to any of Drupal's file system types
using a custom URI scheme, namely, public://, private://, or temp://. This will
read or write the file into the appropriate file system without the developer needing
to know the details of where the files are physically located. Here we are saving our
file to the public file system.
The third argument specifies what file_save_data() should do when a file already
exists with the same name as the file we're trying to save. There are three constants
defined to indicate the possible actions that Drupal can take:
• FILE_EXISTS_REPLACE: The new file should overwrite the existing file.
• FILE_EXISTS_RENAME: Rename the new file by appending an incrementing
number to the new file's name until no collision occurs. For example, if
druplicon.png and druplicon_1.png already existed, then the new file
would be druplicon_2.png.
• FILE_EXISTS_ERROR: Don't do anything and just return FALSE.
The default option is FILE_EXISTS_RENAME but we have specified that the file should
be replaced if it exists.
After the file is saved, a file object is returned. This object contains the fid or file ID,
as well as associated metadata. Now that we have saved the image, we can create a
node and attach the image to it:
$node = new stdClass;
$node->type = 'article';
node_object_prepare($node);
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