The document summarizes various helper functions in CodeIgniter that assist with common programming tasks. It outlines helpers for working with arrays, directories, downloads, email, files, forms, HTML, text, and URLs. For each helper, it lists the loading method and some key functions, such as retrieving array elements, building directory listings, forcing file downloads, validating emails, reading/writing files, and generating form elements.

1. CodeIgniter Helper Functions
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2. Agenda
• Array Helper
• Directory Helper
• Download Helper
• Email Helper
• File Helper
• Form Helper
• HTML Helper
• Text Helper
• URL Helper

3. Array Helper
• The Array Helper file contains functions that assist in
working with arrays.
• $this->load->helper('array');
– Loading helper
• element()
– Lets you fetch an item from an array.
• random_element()
– Takes an array as input and returns a random element
from it.
• elements()
– Lets you fetch a number of items from an array.

4. Directory Helper
• The Directory Helper file contains functions
that assist in working with directories.
• $this->load->helper('directory');
– Loading helper
• directory_map('source directory')
– This function reads the directory path specified in
the first parameter and builds an array
representation of it and all its contained files.

5. Download Helper
• The Download Helper lets you download data to
your desktop.
• $this->load->helper('download');
– Loading the helper
• force_download('filename', 'data')
– Generates server headers which force data to be
downloaded to your desktop. Useful with file
downloads. The first parameter is the name you want
the downloaded file to be named, the second
parameter is the file data.

6. Email Helper
• The Email Helper provides some assistive
functions for working with Email.
• $this->load->helper('email');
– Loading helper
• valid_email('email')
– Checks if an email is a correctly formatted email.
Note that is doesn't actually prove the email will
recieve mail, simply that it is a validly formed
address.

7. File Helper
• The File Helper file contains functions that assist in working
with files.
• $this->load->helper('file');
– Loading helper
• read_file('path')
– Returns the data contained in the file specified in the path.
• write_file('path', $data)
– Writes data to the file specified in the path. If the file does not
exist the function will create it.
• delete_files('path')
– Deletes ALL files contained in the supplied path.
– If the second parameter is set to true, any directories contained
within the supplied root path will be deleted as well.

8. File Helper
• get_filenames('path/to/directory/')
– Takes a server path as input and returns an array
containing the names of all files contained within it.
• get_dir_file_info('path/to/directory/', $top_level
_only = TRUE)
– Reads the specified directory and builds an array
containing the filenames, filesize, dates, and
permissions.
• get_file_info('path/to/file', $file_information)
– Given a file and path, returns the
name, path, size, date modified.

9. File Helper
• get_mime_by_extension('file')
– Translates a file extension into a mime type based on
config/mimes.php.
• symbolic_permissions($perms)
– Takes numeric permissions (such as is returned by
fileperms() and returns standard symbolic notation of
file permissions.
• octal_permissions($perms)
– Takes numeric permissions (such as is returned by
fileperms() and returns a three character octal
notation of file permissions.

10. Form Helper
• The Form Helper file contains functions that assist in
working with forms.
• $this->load->helper('form');
– Loading Helper
• form_open()
– Creates an opening form tag with a base URL built from your
config preferences.
– $attributes = array('class' => 'email', 'id' => 'myform');
– $hidden = array('username' => 'Joe', 'member_id' => '234');
• form_open_multipart()
– This function is absolutely identical to the form_open() tag
above except that it adds a multipart attribute, which is
necessary if you would like to use the form to upload files with.

11. Form Helper
• form_hidden()
– Lets you generate hidden input fields.
• form_input()
– Lets you generate a standard text input field.
• form_password()
• form_upload()
• form_textarea()
• form_dropdown()
– Lets you create a standard drop-down field.
• form_checkbox()
– Lets you generate a checkbox field.
• form_radio()
• form_submit()
• form_reset()
• form_button()
• form_close()

12. HTML Helper
• The HTML Helper file contains functions that assist in working with HTML.
• $this->load->helper('html');
– Loading helper
• br()
– Generates line break tags (<br />) based on the number you submit.
• heading()
– Lets you create HTML <h1> tags. The first parameter will contain the data, the
second the size of the heading.
• img()
– Lets you create HTML <img /> tags. The first parameter contains the image
source.
• nbs()
– Generates non-breaking spaces (&nbsp;) based on the number you submit.

13. Text Helper
• The Text Helper file contains functions that assist in working with
text.
• $this->load->helper('text');
– Loading helper
• word_limiter()
– Truncates a string to the number of words specified.
• character_limiter()
– Truncates a string to the number of characters specified.
• highlight_code()
– Colorizes a string of code (PHP, HTML, etc.).
• word_wrap()
– Wraps text at the specified character count while maintaining
complete words.

14. URL Helper
• The URL Helper file contains functions that assist in working with URLs.
• $this->load->helper('url');
– Loading helper
• site_url()
– Returns your site URL, as specified in your config file.
• base_url()
– Returns your site base URL, as specified in your config file.
• current_url()
– Returns the full URL (including segments) of the page being currently viewed.
• uri_string()
– Returns the URI segments of any page that contains this function.
• index_page()
– Returns your site "index" page, as specified in your config file.

15. URL Helper
• anchor()
– Creates a standard HTML anchor link based on your local site
URL
• anchor_popup()
– Nearly identical to the anchor() function except that it opens the
URL in a new window.
• mailto()
– Creates a standard HTML email link.
• url_title()
– Takes a string as input and creates a human-friendly URL string.
• redirect()
– Does a "header redirect" to the URI specified.

16. DEMO

17. QUESTIONS?