ExpressionEngine Docs

# Functions Class

class `Functions`

- `fetch_site_index([$add_slash = FALSE[, $sess_id = TRUE]])`
- `create_url($segment[, $sess_id = TRUE])`
- `fetch_current_uri()`
- `extract_path($str)`
- `var_swap($str, $data)`
- `redirect($location[, $method = FALSE[, $status_code = NULL]])`
- `random([$type = 'encrypt'[, $len = 8]])`
- `form_declaration($data)`
- `form_backtrack([$offset = ''])`
- `evaluate($str)`
- `char_limiter($str[, $num = 500])`
- `word_limiter($str[, $num = 100])`
- `fetch_email_template($name)`
- `language_pack_names($default)`
- `clear_caching($which[, $sub_dir = ''])`
- `delete_directory($path[, $del_root = FALSE])`
- `fetch_assigned_channels()`
- `fetch_action_id($class, $method)`
- `create_captcha($old_world = '')`
- `sql_andor_string($str, $field[, $prefix = ''[, $null = FALSE]])`
- `assign_variables([$str = ''[, $slash = '/']])`
- `fetch_date_variables($datestr)`
- `assign_parameters($str)`
- `prep_conditionals($str, $vars[, $safety = 'n'[, $prefix = '']])`

The Functions class contains commonly required functions used throughout ExpressionEngine’s scripts.

### `fetch_site_index([$add_slash = FALSE[, $sess_id = TRUE]])`

Parameter | Type | Description
--- | --- | ---
$add_slash | `Boolean` | Set to `TRUE` to add a slash to the end of the return value
$sess_id | `Boolean` | Set to `FALSE` to exclude the session id
Returns | `String` | Site index URL

Returns the url of the main site index.

### `create_url($segment[, $sess_id = TRUE])`

Parameter | Type | Description
--- | --- | ---
$segment | `String` | The desired URL’s URI
$sess_id | `Boolean` | If set to `FALSE`, session_id will not be included
Returns | `String` | Full site URL pointing to `$segment`

The segment passed to this function is parsed and added to the full site URL to create a full URL/URI.

    $memberlist_url = ee()->functions->create_url('member/memberlist');
    // returns "https://example.com/member/memberlist/"

### `fetch_current_uri()`

Parameter | Type | Description
--- | --- | ---
Returns | `String` | Current URI

Returns uri for current page.

### `extract_path($str)`

Parameter | Type | Description
--- | --- | ---
$str | `String` | String to extract the path from
Returns | `String` | Template group/name pair

Extract the template group/template name from `$str`, like `{some_var path='channel/index'}`, and returns just the path.

    // Parse permalink path
    $key = '{permalink path='channel/details'}'
    if (ee()->functions->extract_path($key) != '' && ee()->functions->extract_path($key) != 'SITE_INDEX')
    {
        $path = ee()->functions->extract_path($key).'/'.$row['entry_id'];
    }
    // function returns 'channel/details'

### `var_swap($str, $data)`

Parameter | Type | Description
--- | --- | ---
$str | `String` | String to parse
$data | `Array` | Associative array of keys to replace with values
Returns | `String` | `$str` parsed with `$data`

Replace array of variables in string:

    $str = "Rick and Paul ate {meal} while sitting around the {item}";
    $swap = array('meal' => "Skittles", 'item' => "computer");
    $msg = ee()->functions->var_swap($str, $swap);
    // returns "Rick and Paul ate Skittles while sitting around the computer";

### `redirect($location[, $method = FALSE[, $status_code = NULL]])`

Parameter | Type | Description
--- | --- | ---
$location | `String` | URL to redirect to
$method | `String` | Optionally choose a method to redirect with (can use `refresh`, otherwise defaults to using `Location` header)
$status_code | `Integer` | Status code in the 300 block
Returns | `Void` |

Redirect to location.

### `random([$type = 'encrypt'[, $len = 8]])`

Parameter | Type | Description
--- | --- | ---
$type | `String` | There are four possible values: `basic` - just a random number `alpha` - string with length of length using only letters (upper and lower case) of the alphabet `numeric` - string with length of length using only numbers `nozero` - string with length of length using all numbers except zero `md5` - string of a random number that has been `md5`‘ed `encrypt` - string of a random number that has been hash’ed
$len | `Integer` | Length of the string
Returns | `String` | Random string of characters

Random number/password generator.

### `form_declaration($data)`

Parameter | Type | Description
--- | --- | ---
$data | `Array` | Associative array of data (see above for example)
Returns | `String` | Opening form tag and hidden fields

Creates opening form tag and hidden variables.

Any form will accept the `form_class` and `form_id` parameters. Access the values with TMPL class properties of `form_id` and `form_class`.

    $form_details = array(
        'action'          => '',
        'name'            => 'upload',
        'id'              => ee()->TMPL->form_id,
        'class'           => ee()->TMPL->form_class,
        'hidden_fields'   => array('new' => 'y'),
        'secure'          => TRUE,
        'onsubmit'        => "validate_form(); return false;"
    );

    $r = ee()->functions->form_declaration($form_details);

### `form_backtrack([$offset = ''])`

Parameter | Type | Description
--- | --- | ---
$offset | `Integer` | How many pages you want to backtrack: `0` is the current page, `-1` would be the form page, and `-2` would be the page prior to the form page.
Returns | `String` | Previous URL

Returns a URL that allows us to return a user to a previously visited page after submitting a form. ExpressionEngine keeps track of the last five pages viewed by a visitor, and the page returned is determined by the value of offset.

    $data = array(
        'title'   => 'Information Accepted',
        'heading' => 'Thank you',
        'content' => 'Thank you for the locale information',
        'link'    => array(ee()->functions->form_backtrack('-2'), 'Return to entry')
    );

    ee()->output->show_message($data);

### `evaluate($str)`

Parameter | Type | Description
--- | --- | ---
$str | `String` | String to evaluate as PHP
Returns | `String` | Resulting value

Evaluates a string as PHP:

    $str = "echo 3*4;";

    ob_start();

    echo ee()->functions->evaluate($str);
    $value = ob_get_contents();

    ob_end_clean();

    // $value is now equal to 12, since that is what would be outputted by the PHP.

### `char_limiter($str[, $num = 500])`

Parameter | Type | Description
--- | --- | ---
$str | `String` | String to limit
$num | `Interger` | Characters to limit to
Returns | `String` | Limited string

Returns section of a string limited to a certain amount of characters but rounds the string up to the nearest word.

### `word_limiter($str[, $num = 100])`

Parameter | Type | Description
--- | --- | ---
$str | `String` | String to limit
$num | `Interger` | Words to limit to
Returns | `String` | Limited string

Returns section of a string based on number of words.

### `fetch_email_template($name)`

Parameter | Type | Description
--- | --- | ---
$name | `String` | Name of the email template
Returns | `String` | Email template parsed with the user’s language

Returns the contents of the email template requested based on the language settings of the user.

### `language_pack_names($default)`

Parameter | Type | Description
--- | --- | ---
$default | `String` | Currently selected or default language
Returns | `String` | Div tag with a select tag that contains the listing of languages

Returns form select menu of available language packs

### `clear_caching($which[, $sub_dir = ''])`

Parameter | Type | Description
--- | --- | ---
$which | `String` | `'page'`, `'tag'`, `'db'`, `'sql'`, `'relationships'`, `'all'`
$sub_dir | `String` | Define a specific folder or file in the cache directory
Returns | `Void` |

Clears one or all of the main cache folders

### `delete_directory($path[, $del_root = FALSE])`

Parameter | Type | Description
--- | --- | ---
$path | `String` | Absolute path of the directory you wish to empty; remember to use the path constants to make this easier
$del_root | `Boolean` | Set to `TRUE` to delete the directory as well
Returns | `Void` |

Empties a directory of any files.

### `fetch_assigned_channels()`

Parameter | Type | Description
--- | --- | ---
Returns | `Array` | Array of channels accessible by current user

Returns array of channels accessible by current user.

### `fetch_action_id($class, $method)`

Parameter | Type | Description
--- | --- | ---
$class | `String` | Class that contains the `$method`
$method | `String` | Name of the method that has an action ID
Returns | `String` | Valid action ID tag

Returns a tag in the format `{AID:class:method}` for use in the frontend. (See also EE->cp->fetch_action_id).

    $action_id = ee()->functions->fetch_action_id('Comment', 'insert_new_comment');

### `create_captcha($old_world = '')`

Parameter | Type | Description
--- | --- | ---
$old_word | `String` | Can specify the word to appear as a captcha
Returns | `String` | `<img>` tag

Using a random word chosen from the array stored in the `config/captcha.php` file, this function will create a captcha image and then store that word and the IP address of the current user in the database. You can then put the returned `<img>` tag in your form along with a text input field for the user submitted word. When the form is submitted you can check the submitted word against the database for the user’s IP. If it matches, you continue processing the form data. If it does not, then the form should fail. This is used to prevent automated spamming tools from submitting spam.

### `sql_andor_string($str, $field[, $prefix = ''[, $null = FALSE]])`

Parameter | Type | Description
--- | --- | ---
$str | `String` | Pipe delimited string from the tag parameter
$field | `String` | Name of the database field
$prefix | `String` | Field prefix, used when working with multiple tables to define the table (e.g. `database_table_name.field_name`)
$null | `Boolean` | Allow for null values in the `$field`
Returns | `String` | Partial query string containing some of the `WHERE` clause

Certain tag parameters have the option to be in the form of `'value1|value2'` or `'not value1|value2'`, which allows the acceptance of multiple values. This function takes that parameter as `$str` and the `$field` to check, along with the (optional) `$prefix` of the table containing the field, and returns the query string required:

    $str  = 'channel|news|sports';
    $sql  = "SELECT * FROM exp_channels WHERE site_id = 1 ";
    $sql .= ee()->functions->sql_andor_string($str, 'channel_name');
    // $sql equals:
    // SELECT * FROM exp_channels WHERE site_id = 1
    // AND channel_name = 'channel' OR channel_name = 'news' OR channel_name = 'sports'

### `assign_variables([$str = ''[, $slash = '/']])`

Parameter | Type | Description
--- | --- | ---
$str | `String` | String to parse
$slash | `String` | What kind of backslash is in the string (`/` or `&#47;`)
Returns | `Array` | Associative array containing both `var_single` and `var_pair`

This function extracts the variables contained within the current tag being parsed and assigns them to one of two arrays which are returned to you: `var_single` or `var_pair`.

### `fetch_date_variables($datestr)`

Parameter | Type | Description
--- | --- | ---
$datestr | `String` | The string to look for a single date format in
Returns | `String` | Date format string

Fetch the date format (e.g. `%Y %m %d`) from a date variable (e.g. `{date format="%Y %m %d"}`).

### `assign_parameters($str)`

Parameter | Type | Description
--- | --- | ---
$str | `String` | String containing tag parameters directly from the `TMPL::$tagdata`
Returns | `Array` | Associative array containing the tag parameters

Fetch parameters for tag

### `prep_conditionals($str, $vars[, $safety = 'n'[, $prefix = '']])`

Parameter | Type | Description
--- | --- | ---
$str | `String` | Template `TMPL::$tagdata` to parse
$vars | `Array` | Associative array of conditionals to parse
$safety | `String` | Set to `'y'` to ensure that some safety checks are performed to make sure conditionals are well formed
$prefix | `String` | Used when your variables have a prefix, parses both prefixed and non-prefixed variables
Returns | `String` | `$str` with the conditionals from `$var` parsed

Parses conditionals and preps conditional for evaluation