path: root/user_guide_src/source/helpers/form_helper.rst

###########
Form Helper
###########

The Form Helper file contains functions that assist in working with
forms.

.. contents:: Page Contents

Loading this Helper
===================

This helper is loaded using the following code::

	$this->load->helper('form');

The following functions are available:

form_open()
===========

.. php:function:: form_open($action = '', $attributes = '', $hidden = array())

	:param	string	$action: Form action/target URI string
	:param	array	$attributes: HTML attributes
	:param	array	$hidden: An array of hidden fields' definitions
	:returns:	string

Creates an opening form tag with a base URL **built from your config preferences**.
It will optionally let you add form attributes and hidden input fields, and
will always add the `accept-charset` attribute based on the charset value in your
config file.

The main benefit of using this tag rather than hard coding your own HTML is that
it permits your site to be more portable in the event your URLs ever change.

Here's a simple example::

	echo form_open('email/send');

The above example would create a form that points to your base URL plus the
"email/send" URI segments, like this::

	<form method="post" accept-charset="utf-8" action="http://example.com/index.php/email/send">

Adding Attributes
^^^^^^^^^^^^^^^^^

Attributes can be added by passing an associative array to the second
parameter, like this::

	$attributes = array('class' => 'email', 'id' => 'myform');
	echo form_open('email/send', $attributes);

Alternatively, you can specify the second parameter as a string::

	echo form_open('email/send', 'class="email" id="myform"');

The above examples would create a form similar to this::

	<form method="post" accept-charset="utf-8" action="http://example.com/index.php/email/send" class="email" id="myform">

Adding Hidden Input Fields
^^^^^^^^^^^^^^^^^^^^^^^^^^

Hidden fields can be added by passing an associative array to the
third parameter, like this::

	$hidden = array('username' => 'Joe', 'member_id' => '234');
	echo form_open('email/send', '', $hidden);

You can skip the second parameter by passing any falsy value to it.

The above example would create a form similar to this::

	<form method="post" accept-charset="utf-8" action="http://example.com/index.php/email/send">
		<input type="hidden" name="username" value="Joe" />
		<input type="hidden" name="member_id" value="234" />

form_open_multipart()
=====================

.. php:function:: form_open_multipart($action = '', $attributes = array(), $hidden = array())

	:param	string	$action: Form action/target URI string
	:param	array	$attributes: HTML attributes
	:param	array	$hidden: An array of hidden fields' definitions
	:returns:	string

This function is absolutely identical to :php:func:`form_open()` above,
except that it adds a *multipart* attribute, which is necessary if you
would like to use the form to upload files with.

form_hidden()
=============

.. php:function:: form_hidden($name, $value = '')

	:param	string	$name: Field name
	:param	string	$value: Field value
	:returns:	string

Lets you generate hidden input fields. You can either submit a
name/value string to create one field::

	form_hidden('username', 'johndoe');
	// Would produce: <input type="hidden" name="username" value="johndoe" />

... or you can submit an associative array to create multiple fields::

	$data = array(
		'name'	=> 'John Doe',
		'email'	=> 'john@example.com',
		'url'	=> 'http://example.com'
	);

	echo form_hidden($data);

	/*
		Would produce:
		<input type="hidden" name="name" value="John Doe" />
		<input type="hidden" name="email" value="john@example.com" />
		<input type="hidden" name="url" value="http://example.com" />
	*/

You can also pass an associative array to the value field::

	$data = array(
		'name'	=> 'John Doe',
		'email'	=> 'john@example.com',
		'url'	=> 'http://example.com'
	);

	echo form_hidden('my_array', $data);

	/*
		Would produce:

		<input type="hidden" name="my_array[name]" value="John Doe" />
		<input type="hidden" name="my_array[email]" value="john@example.com" />
		<input type="hidden" name="my_array[url]" value="http://example.com" />
	*/

If you want to create hidden input fields with extra attributes::

	$data = array(
		'type'	=> 'hidden',
		'name'	=> 'email',
		'id'	=> 'hiddenemail',
		'value'	=> 'john@example.com',
		'class'	=> 'hiddenemail'
	);

	echo form_input($data);

	/*
		Would produce:

		<input type="hidden" name="email" value="john@example.com" id="hiddenemail" class="hiddenemail" />
	*/

form_input()
============

.. php:function:: form_input($data = '', $value = '', $extra = '')

	:param	array	$data: Field attributes data
	:param	string	$value: Field value
	:param	string	$extra: Extra attributes to be added to the tag *as is*
	:returns:	string

Lets you generate a standard text input field. You can minimally pass
the field name and value in the first and second parameter::

	echo form_input('username', 'johndoe');

Or you can pass an associative array containing any data you wish your
form to contain::

	$data = array(
		'name'		=> 'username',
		'id'		=> 'username',
		'value'		=> 'johndoe',
		'maxlength'	=> '100',
		'size'		=> '50',
		'style'		=> 'width:50%'
	);

	echo form_input($data);

	/*
		Would produce:

		<input type="text" name="username" value="johndoe" id="username" maxlength="100" size="50" style="width:50%"  />
	*/

If you would like your form to contain some additional data, like
JavaScript, you can pass it as a string in the third parameter::

	$js = 'onClick="some_function()"';
	echo form_input('username', 'johndoe', $js);

form_password()
===============

.. php:function:: form_password($data = '', $value = '', $extra = '')

	:param	array	$data: Field attributes data
	:param	string	$value: Field value
	:param	string	$extra: Extra attributes to be added to the tag *as is*
	:returns:	string

This function is identical in all respects to the :php:func:`form_input()`
function above except that it uses the "password" input type.

form_upload()
=============

.. php:function:: form_upload($data = '', $value = '', $extra = '')

	:param	array	$data: Field attributes data
	:param	string	$value: Field value
	:param	string	$extra: Extra attributes to be added to the tag *as is*
	:returns:	string

This function is identical in all respects to the :php:func:`form_input()`
function above except that it uses the "file" input type, allowing it to
be used to upload files.

form_textarea()
===============

.. php:function:: form_textarea($data = '', $value = '', $extra = '')

	:param	array	$data: Field attributes data
	:param	string	$value: Field value
	:param	string	$extra: Extra attributes to be added to the tag *as is*
	:returns:	string

This function is identical in all respects to the :php:func:`form_input()`
function above except that it generates a "textarea" type.

.. note: Instead of the *maxlength* and *size* attributes in the above example,
	you will instead specify *rows* and *cols*.

form_dropdown()
===============

.. php:function:: form_dropdown($name = '', $options = array(), $selected = array(), $extra = '')

	:param	string	$name: Field name
	:param	array	$options: An associative array of options to be listed
	:param	array	$selected: List of fields to mark with the *selected* attribute
	:param	string	$extra: Extra attributes to be added to the tag *as is*
	:returns:	string

Lets you create a standard drop-down field. The first parameter will
contain the name of the field, the second parameter will contain an
associative array of options, and the third parameter will contain the
value you wish to be selected. You can also pass an array of multiple
items through the third parameter, and CodeIgniter will create a
multiple select for you.

Example::

	$options = array(
		'small'		=> 'Small Shirt',
		'med'		=> 'Medium Shirt',
		'large'		=> 'Large Shirt',
		'xlarge'	=> 'Extra Large Shirt',
	);

	$shirts_on_sale = array('small', 'large');
	echo form_dropdown('shirts', $options, 'large');

	/*
		Would produce:

		<select name="shirts">
			<option value="small">Small Shirt</option>
			<option value="med">Medium  Shirt</option>
			<option value="large" selected="selected">Large Shirt</option>
			<option value="xlarge">Extra Large Shirt</option>
		</select>
	*/

	echo form_dropdown('shirts', $options, $shirts_on_sale);

	/*
		Would produce:

		<select name="shirts" multiple="multiple">
			<option value="small" selected="selected">Small Shirt</option>
			<option value="med">Medium  Shirt</option>
			<option value="large" selected="selected">Large Shirt</option>
			<option value="xlarge">Extra Large Shirt</option>
		</select>
	*/

If you would like the opening <select> to contain additional data, like
an id attribute or JavaScript, you can pass it as a string in the fourth
parameter::

	$js = 'id="shirts" onChange="some_function();"';
	echo form_dropdown('shirts', $options, 'large', $js);

If the array passed as ``$options`` is a multidimensional array, then
``form_dropdown()`` will produce an <optgroup> with the array key as the
label.

form_multiselect()
==================

.. php:function:: form_multiselect($name = '', $options = array(), $selected = array(), $extra = '')

	:param	string	$name: Field name
	:param	array	$options: An associative array of options to be listed
	:param	array	$selected: List of fields to mark with the *selected* attribute
	:param	string	$extra: Extra attributes to be added to the tag *as is*
	:returns:	string

Lets you create a standard multiselect field. The first parameter will
contain the name of the field, the second parameter will contain an
associative array of options, and the third parameter will contain the
value or values you wish to be selected.

The parameter usage is identical to using :php:func:`form_dropdown()` above,
except of course that the name of the field will need to use POST array
syntax, e.g. foo[].

form_fieldset()
===============

.. php:function:: form_fieldset($legend_text = '', $attributes = array())

	:param	string	$legend_text: Text to put in the <legend> tag
	:param	array	$attributes: Attributes to be set on the <fieldset> tag
	:returns:	string

Lets you generate fieldset/legend fields.

Example::

	echo form_fieldset('Address Information');
	echo "<p>fieldset content here</p>\n";
	echo form_fieldset_close();

	/*
		Produces:

			<fieldset>
				<legend>Address Information</legend>
					<p>form content here</p>
			</fieldset>
	*/

Similar to other functions, you can submit an associative array in the
second parameter if you prefer to set additional attributes::

	$attributes = array(
		'id'	=> 'address_info',
		'class'	=> 'address_info'
	);

	echo form_fieldset('Address Information', $attributes);
	echo "<p>fieldset content here</p>\n";
	echo form_fieldset_close();

	/*
		Produces:

		<fieldset id="address_info" class="address_info">
			<legend>Address Information</legend>
			<p>form content here</p>
		</fieldset>
	*/

form_fieldset_close()
=====================

.. php:function:: form_fieldset_close($extra = '')

	:param	string	$extra: Anything to append after the closing tag, *as is*
	:returns:	string

Produces a closing </fieldset> tag. The only advantage to using this
function is it permits you to pass data to it which will be added below
the tag. For example

::

	$string = '</div></div>';
	echo form_fieldset_close($string);
	// Would produce: </fieldset></div></div>

form_checkbox()
===============

.. php:function:: form_checkbox($data = '', $value = '', $checked = FALSE, $extra = '')

	:param	array	$data: Field attributes data
	:param	string	$value: Field value
	:param	bool	$checked: Whether to mark the checkbox as being *checked*
	:param	string	$extra: Extra attributes to be added to the tag *as is*
	:returns:	string

Lets you generate a checkbox field. Simple example::

	echo form_checkbox('newsletter', 'accept', TRUE);
	// Would produce:  <input type="checkbox" name="newsletter" value="accept" checked="checked" />

The third parameter contains a boolean TRUE/FALSE to determine whether
the box should be checked or not.

Similar to the other form functions in this helper, you can also pass an
array of attributes to the function::

	$data = array(
		'name'		=> 'newsletter',
		'id'		=> 'newsletter',
		'value'		=> 'accept',
		'checked'	=> TRUE,
		'style'		=> 'margin:10px'
	);

	echo form_checkbox($data);
	// Would produce: <input type="checkbox" name="newsletter" id="newsletter" value="accept" checked="checked" style="margin:10px" />

Also as with other functions, if you would like the tag to contain
additional data like JavaScript, you can pass it as a string in the
fourth parameter::

	$js = 'onClick="some_function()"';
	echo form_checkbox('newsletter', 'accept', TRUE, $js)

form_radio()
============

.. php:function:: form_radio($data = '', $value = '', $checked = FALSE, $extra = '')

	:param	array	$data: Field attributes data
	:param	string	$value: Field value
	:param	bool	$checked: Whether to mark the radio button as being *checked*
	:param	string	$extra: Extra attributes to be added to the tag *as is*
	:returns:	string

This function is identical in all respects to the :php:func:`form_checkbox()`
function above except that it uses the "radio" input type.

form_label()
============

.. php:function:: form_label($label_text = '', $id = '', $attributes = array())

	:param	string	$label_text: Text to put in the <label> tag
	:param	string	$id: ID of the form element that we're making a label for
	:param	string	$attributes: HTML attributes
	:returns:	string

Lets you generate a <label>. Simple example::

	echo form_label('What is your Name', 'username');
	// Would produce:  <label for="username">What is your Name</label>

Similar to other functions, you can submit an associative array in the
third parameter if you prefer to set additional attributes.

Example::

	$attributes = array(
		'class' => 'mycustomclass',
		'style' => 'color: #000;'
	);

	echo form_label('What is your Name', 'username', $attributes);
	// Would produce:  <label for="username" class="mycustomclass" style="color: #000;">What is your Name</label>

form_submit()
=============

.. php:function:: form_submit($data = '', $value = '', $extra = '')

	:param	string	$data: Button name
	:param	string	$value: Button value
	:param	string	$extra: Extra attributes to be added to the tag *as is*
	:returns:	string

Lets you generate a standard submit button. Simple example::

	echo form_submit('mysubmit', 'Submit Post!');
	// Would produce:  <input type="submit" name="mysubmit" value="Submit Post!" />

Similar to other functions, you can submit an associative array in the
first parameter if you prefer to set your own attributes. The third
parameter lets you add extra data to your form, like JavaScript.

form_reset()
============

.. php:function:: form_reset($data = '', $value = '', $extra = '')

	:param	string	$data: Button name
	:param	string	$value: Button value
	:param	string	$extra: Extra attributes to be added to the tag *as is*
	:returns:	string

Lets you generate a standard reset button. Use is identical to
:php:func:`form_submit()`.

form_button()
=============

.. php:function:: form_button($data = '', $content = '', $extra = '')

	:param	string	$data: Button name
	:param	string	$content: Button label
	:param	string	$extra: Extra attributes to be added to the tag *as is*
	:returns:	string

Lets you generate a standard button element. You can minimally pass the
button name and content in the first and second parameter::

	echo form_button('name','content');
	// Would produce: <button name="name" type="button">Content</button>

Or you can pass an associative array containing any data you wish your
form to contain::

	$data = array(
		'name'		=> 'button',
		'id'		=> 'button',
		'value'		=> 'true',
		'type'		=> 'reset',
		'content'	=> 'Reset'
	);

	echo form_button($data);
	// Would produce: <button name="button" id="button" value="true" type="reset">Reset</button>

If you would like your form to contain some additional data, like
JavaScript, you can pass it as a string in the third parameter::

	$js = 'onClick="some_function()"';
	echo form_button('mybutton', 'Click Me', $js);

form_close()
============

.. php:function:: form_close($extra = '')

	:param	string	$extra: Anything to append after the closing tag, *as is*
	:returns:	string

Produces a closing </form> tag. The only advantage to using this
function is it permits you to pass data to it which will be added below
the tag. For example::

	$string = '</div></div>';
	echo form_close($string);
	// Would produce:  </form> </div></div>

form_prep()
===========

.. php:function:: form_prep($str = '', $is_textarea = FALSE)

	:param	string	$str: Value to escape
	:param	bool	$is_textarea: Whether we're preparing for <textarea> or a regular input tag
	:returns:	string

Allows you to safely use HTML and characters such as quotes within form
elements without breaking out of the form.

Consider this example::

	$string = 'Here is a string containing "quoted" text.';
	<input type="text" name="myform" value="$string" />

Since the above string contains a set of quotes it will cause the form
to break. The ``form_prep()`` function converts HTML so that it can be used
safely::

	<input type="text" name="myform" value="<?php echo form_prep($string); ?>" />

.. note:: If you use any of the form helper functions listed in this page the form
	values will be prepped automatically, so there is no need to call this
	function. Use it only if you are creating your own form elements.

set_value()
===========

.. php:function:: set_value($field = '', $default = '', $is_textarea = FALSE)

	:param	string	$field: Field name
	:param	string	$default: Default value
	:param	bool	$is_textarea: Whether we're setting <textarea> content
	:returns:	string

Permits you to set the value of an input form or textarea. You must
supply the field name via the first parameter of the function. The
second (optional) parameter allows you to set a default value for the
form.

Example::

	<input type="text" name="quantity" value="<?=set_value('quantity', '0');?>" size="50" />

The above form will show "0" when loaded for the first time.

set_select()
============

.. php:function:: set_select($field = '', $value = '', $default = FALSE)

	:param	string	$field: Field name
	:param	string	$value: Value to check for
	:param	string	$default: Whether the value is also a default one
	:returns:	string

If you use a <select> menu, this function permits you to display the
menu item that was selected.

The first parameter must contain the name of the select menu, the second
parameter must contain the value of each item, and the third (optional)
parameter lets you set an item as the default (use boolean TRUE/FALSE).

Example::

	<select name="myselect">
		<option value="one" <?php echo  set_select('myselect', 'one', TRUE); ?> >One</option>
		<option value="two" <?php echo  set_select('myselect', 'two'); ?> >Two</option>
		<option value="three" <?php echo  set_select('myselect', 'three'); ?> >Three</option>
	</select>

set_checkbox()
==============

.. php:function:: set_checkbox($field = '', $value = '', $default = FALSE)

	:param	string	$field: Field name
	:param	string	$value: Value to check for
	:param	string	$default: Whether the value is also a default one
	:returns:	string

Permits you to display a checkbox in the state it was submitted.

The first parameter must contain the name of the checkbox, the second
parameter must contain its value, and the third (optional) parameter
lets you set an item as the default (use boolean TRUE/FALSE).

Example::

	<input type="checkbox" name="mycheck" value="1" <?php echo set_checkbox('mycheck', '1'); ?> />
	<input type="checkbox" name="mycheck" value="2" <?php echo set_checkbox('mycheck', '2'); ?> />

set_radio()
===========

.. php:function:: set_radio($field = '', $value = '', $default = FALSE)

	:param	string	$field: Field name
	:param	string	$value: Value to check for
	:param	string	$default: Whether the value is also a default one
	:returns:	string

Permits you to display radio buttons in the state they were submitted.
This function is identical to the :php:func:`set_checkbox()` function above.

Example::

	<input type="radio" name="myradio" value="1" <?php echo  set_radio('myradio', '1', TRUE); ?> />
	<input type="radio" name="myradio" value="2" <?php echo  set_radio('myradio', '2'); ?> />

.. note:: If you are using the Form Validation class, you must always specify
	a rule for your field, even if empty, in order for the ``set_*()``
	functions to work. This is because if a Form Validation object is
	defined, the control for ``set_*()`` is handed over to a method of the
	class instead of the generic helper function.

form_error()
============

.. php:function:: form_error($field = '', $prefix = '', $suffix = '')

	:param	string	$field:	Field name
	:param	string	$prefix: Error opening tag
	:param	string	$suffix: Error closing tag
	:returns:	string

Returns a validation error message from the :doc:`Form Validation Library
<../libraries/form_validation>`, associated with the specified field name.
You can optionally specify opening and closing tag(s) to put around the error
message.

Example::

	// Assuming that the 'username' field value was incorrect:
	echo form_error('myfield', '<div class="error">', '</div>');

	// Would produce: <div class="error">Error message associated with the "username" field.</div>

validation_errors()
===================

.. php:function:: validation_errors($prefix = '', $suffix = '')

	:param	string	$prefix: Error opening tag
	:param	string	$suffix: Error closing tag
	:returns:	string

Similarly to the :php:func:`form_error()` function, returns all validation
error messages produced by the :doc:`Form Validation Library
<../libraries/form_validation>`, with optional opening and closing tags
around each of the messages.

Example::

	echo validation_errors('<span class="error">', '</span>');

	/*
		Would produce, e.g.:

		<span class="error">The "email" field doesn't contain a valid e-mail address!</span>
		<span class="error">The "password" field doesn't match the "repeat_password" field!</span>

	 */