Plugin / If File Exists

Description

This plugin provides the functions c2c_if_file_exists(), c2c_if_theme_file_exists(), c2c_if_plugin_file_exists() that check if a file exists and either return true/false or display a string containing information about the file.

• If a format string is not passed to it, the functions return a simple boolean (true or false) indicating if the specified file exists.
• Otherwise, the format string provided to it will be used to construct a response string, which can be customized to display information about the file (such as file_name, file_url, or file_path). If the $echo argument is true, that string is displayed on the page. Regardless of the value of $echo, the response string is returned by the function.

By default, ‘c2c_if_file_exists()’ assumes you are looking for the file relative to the default WordPress upload directory. If you wish to search another directory, specify it as the $dir argument. ‘c2c_if_theme_file_exists()’ assumes you are looking for a file relative to the currently active theme’s home directory. ‘c2c_if_plugin_file_exists()’ assumes you are looking for a file relative to the directory that contains WordPress plugins.

Links: Plugin Homepage | Plugin Directory Page | GitHub | Author Homepage

Template Tags

The plugin provides three template tags for use in your theme templates.

Functions

• <?php function c2c_if_file_exists($filename, $format = '', $echo = true, $dir = '') ?>
  Checks if a file exists and returns true/false or displays a string containing information about the file.
• <?php function c2c_if_plugin_file_exists( $filename, $format = '', $echo = true, $dir = '', $show_if_not_exists = '' ) ?>
  Checks if a file exists (relative to the plugins directory) and returns true/false or displays a string containing information about the file.
• <?php function c2c_if_theme_file_exists( $filename, $format = '', $echo = true, $dir = '', $show_if_not_exists = '' ) ?>
  Checks if a file exists (relative to the current theme’s directory) and returns true/false or displays a string containing information about the file. If the current theme is a child theme, then the function will check if the file exists first in the child theme’s directory, and if not there, then it will check the parent theme’s directory.

Arguments

• $filename
  String. Name of the filename whose existence is being checked. Do not include path information.

• $format
  (optional) String. Text to be displayed or returned when $filename exists. Leave blank to return true or false. The following percent-tag substitutions are available for optional use in the $format string:

  • %file_directory% : the directory of the file, i.e. “/usr/local/www/yoursite/wp-content/uploads/”
  • %file_extension% : the extension of the file, i.e. “zip”`
  • %file_name% : the name of the file, i.e. “pictures.zip”
  • %file_url% : the URL of the file, i.e. “http://yoursite.com/wp-content/uploads/pictures.zip”
  • %file_path%: the filesystem path to the file, i.e. “/usr/local/www/yoursite/wp-content/uploads/pictures.zip”

• $echo
  (optional) Boolean. Should $format be echoed when the filename exists? NOTE: the string always gets returned unless file does not exist). Default is true.

• $dir
  (optional) String|Boolean. The directory (relative to the root of the site) to check for $filename. If empty, the WordPress upload directory is assumed (if using c2c_if_file_exists()). If ‘true’, then it indicates the filename includes the directory.

• $show_if_not_exists
  (optional) String. Text to display if the file does not exists. $format must also be specified. Format is the same as $format argument.

Examples

• <?php
$format = "<a href='%file_url%'>Download %file_name% now!</a>";
$file_name = 'pictures-' . get_the_ID() . '.zip';
c2c_if_file_exists($file_name, $format);
?>

• <?php
if ( c2c_if_file_exists($file_name) ) {
// Do stuff here
}
?>

• <?php c2c_if_file_exists($file_name, '%file_name% exists!'); ?>

• <?php c2c_if_file_exists($file_name, '%file_name% also exists in upload2 directory', true, 'wp-content/uploads2'); ?>

• <?php c2c_if_file_exists($file_name, '%file_name% also exists in upload2 directory', true, 'wp-content/uploads2', '%file_name% did not exist!'); ?>

• <?php c2c_if_plugin_file_exists('akismet.php', 'Akismet is present', true, 'akismet'); ?>

• <?php c2c_if_plugin_file_exists('akismet/akismet.php', 'Akismet is present', true, true); ?>

• <?php c2c_if_theme_file_exists('home.php', 'Home template is present', true, '', 'Home template does not exist.'); ?>

Hooks

The plugin exposes three filters for hooking. Code using these filters should ideally be put into a mu-plugin or site-specific plugin (which is beyond the scope of this readme to explain). Less ideally, you could put them in your active theme’s functions.php file.

c2c_if_file_exists (filter)

The ‘c2c_if_file_exists’ hook allows you to use an alternative approach to safely invoke c2c_if_file_exists() in such a way that if the plugin were deactivated or deleted, then your calls to the function won’t cause errors in your site.

Arguments:

• same as for c2c_if_file_exists()

Example:

Instead of:

<?php c2c_if_file_exists( $file, '%file_url%' ); ?>

Do:

<?php apply_filters( 'c2c_if_file_exists', $file, '%file_url%' ); ?>

c2c_if_plugin_file_exists (filter)

The ‘c2c_if_plugin_file_exists’ hook allows you to use an alternative approach to safely invoke c2c_if_plugin_file_exists() in such a way that if the plugin were deactivated or deleted, then your calls to the function won’t cause errors in your site.

Arguments:

• same as for c2c_if_plugin_file_exists()

Example:

Instead of:

<?php $exists = c2c_if_plugin_file_exists( $file ); ?>

Do:

<?php $exists = apply_filters( 'c2c_if_plugin_file_exists', $file ); ?>

c2c_if_theme_file_exists (filter)

The ‘c2c_if_theme_file_exists’ hook allows you to use an alternative approach to safely invoke c2c_if_theme_file_exists() in such a way that if the plugin were deactivated or deleted, then your calls to the function won’t cause errors in your site.

Arguments:

• same as for c2c_if_theme_file_exists()

Example:

Instead of:

<?php $exists = c2c_if_theme_file_exists( $file ); ?>

Do:

<?php $exists = apply_filters( 'c2c_if_theme_file_exists', $file ); ?>