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

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

.. contents::
  :local:

.. raw:: html

  <div class="custom-index container"></div>

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

This helper is loaded using the following code::

	helper('form');

Escaping field values
=====================

You may need to use HTML and characters such as quotes within your form
elements. In order to do that safely, you'll need to use
:doc:`common function <../general/common_functions>`
:func:`esc()`.

Consider the following example::

	$string = 'Here is a string containing "quoted" text.';

	<input type="text" name="myfield" value="<?= $string; ?>" />

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

	<input type="text" name="myfield" value="<?= esc($string); ?>" />

.. note:: If you use any of the form helper functions listed on this page,
        and you pass values as an associative array,
	the form values will be automatically escaped, so there is no need
	to call this function. Use it only if you are creating your own
	form elements, which you would pass as strings.

Available Functions
===================

The following functions are available:

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

	:param	string	$action: Form action/target URI string
    	:param	mixed	$attributes: HTML attributes, as an array or escaped string
    	:param	array	$hidden: An array of hidden fields' definitions
    	:returns:	An HTML form opening tag
    	:rtype:	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 = ['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">
			
		If CSRF filter is turned on `form_open()` will generate CSRF field at the beginning of the form. You can specify ID of this field by passing csrf_id as one of the $attribute array:
		
			form_open('/u/sign-up', ['csrf_id' => 'my-id']);
			
		will return:
		
			<form action="/u/sign-up" method="post" accept-charset="utf-8">
			<input type="hidden" id="my-id" name="csrf_field" value="964ede6e0ae8a680f7b8eab69136717d" />

	**Adding Hidden Input Fields**

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

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

		You can skip the second parameter by passing any false 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" />

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

	:param	string	$action: Form action/target URI string
    	:param	mixed	$attributes: HTML attributes, as an array or escaped string
    	:param	array	$hidden: An array of hidden fields' definitions
    	:returns:	An HTML multipart form opening tag
    	:rtype:	string

    	This function is 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.

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

	:param	string	$name: Field name
    	:param	string	$value: Field value
    	:returns:	An HTML hidden input field tag
    	:rtype:	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 = [
			'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 = [
			'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 = [
			'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" />
		*/

.. php:function:: form_input([$data = ''[, $value = ''[, $extra = ''[, $type = 'text']]]])

	:param	array	$data: Field attributes data
	:param	string	$value: Field value
	:param	mixed	$extra: Extra attributes to be added to the tag either as an array or a literal string
	:param  string  $type: The type of input field. i.e. 'text', 'email', 'number', etc.
	:returns:	An HTML text input field tag
	:rtype:	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 = [
			'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);

	Or you can pass it as an array::

		$js = ['onClick' => 'some_function();'];
		echo form_input('username', 'johndoe', $js);

	To support the expanded range of HTML5 input fields, you can pass an input type in as the fourth parameter::

		echo form_input('email', 'joe@example.com', ['placeholder' => 'Email Address...'], 'email');

		/*
			 Would produce:

			<input type="email" name="email" value="joe@example.com" placeholder="Email Address..." />
		*/

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

	:param	array	$data: Field attributes data
    	:param	string	$value: Field value
    	:param	mixed	$extra: Extra attributes to be added to the tag either as an array or a literal string
    	:returns:	An HTML password input field tag
    	:rtype:	string

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

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

	:param	array	$data: Field attributes data
    	:param	string	$value: Field value
    	:param	mixed	$extra: Extra attributes to be added to the tag either as an array or a literal string
    	:returns:	An HTML file upload input field tag
    	:rtype:	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.

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

	:param	array	$data: Field attributes data
    	:param	string	$value: Field value
    	:param	mixed	$extra: Extra attributes to be added to the tag either as an array or a literal string
    	:returns:	An HTML textarea tag
    	:rtype:	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*.

.. php:function:: form_dropdown([$name = ''[, $options = [][, $selected = [][, $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	mixed	$extra: Extra attributes to be added to the tag either as an array or a literal string
    	:returns:	An HTML dropdown select field tag
    	:rtype:	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 the helper will create a
    	multiple select for you.

    	Example::

		$options = [
			'small'  => 'Small Shirt',
			'med'    => 'Medium Shirt',
			'large'  => 'Large Shirt',
			'xlarge' => 'Extra Large Shirt',
		];

		$shirts_on_sale = ['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);

	Or you can pass it as an array::

		$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.

.. php:function:: form_multiselect([$name = ''[, $options = [][, $selected = [][, $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	mixed	$extra: Extra attributes to be added to the tag either as an array or a literal string
    	:returns:	An HTML dropdown multiselect field tag
    	:rtype:	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[].

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

	:param	string	$legend_text: Text to put in the <legend> tag
    	:param	array	$attributes: Attributes to be set on the <fieldset> tag
    	:returns:	An HTML fieldset opening tag
    	:rtype:	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 = [
			'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>
		*/

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

	:param	string	$extra: Anything to append after the closing tag, *as is*
	:returns:	An HTML fieldset closing tag
	:rtype:	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>

.. 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	mixed	$extra: Extra attributes to be added to the tag either as an array or a literal string
    	:returns:	An HTML checkbox input tag
    	:rtype:	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 = [
			'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);

	Or you can pass it as an array::

		$js = ['onClick' => 'some_function();'];
		echo form_checkbox('newsletter', 'accept', TRUE, $js);

.. 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	mixed	$extra: Extra attributes to be added to the tag either as an array or a literal string
    	:returns:	An HTML radio input tag
    	:rtype:	string

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

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

	: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:	An HTML field label tag
    	:rtype:	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 = [
			'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>

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

	:param	string	$data: Button name
    	:param	string	$value: Button value
    	:param	mixed	$extra: Extra attributes to be added to the tag either as an array or a literal string
    	:returns:	An HTML input submit tag
    	:rtype:	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.

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

	:param	string	$data: Button name
    	:param	string	$value: Button value
    	:param	mixed	$extra: Extra attributes to be added to the tag either as an array or a literal string
    	:returns:	An HTML input reset button tag
    	:rtype:	string

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

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

	:param	string	$data: Button name
    	:param	string	$content: Button label
    	:param	mixed	$extra: Extra attributes to be added to the tag either as an array or a literal string
    	:returns:	An HTML button tag
    	:rtype:	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 = [
			'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);

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

	:param	string	$extra: Anything to append after the closing tag, *as is*
	:returns:	An HTML form closing tag
	:rtype:	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>

.. php:function:: set_value($field[, $default = ''[, $html_escape = TRUE]])

	:param	string	$field: Field name
    	:param	string	$default: Default value
    	:param  bool	$html_escape: Whether to turn off HTML escaping of the value
    	:returns:	Field value
    	:rtype:	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. The third (optional) parameter allows you to turn off HTML escaping
    	of the value, in case you need to use this function in combination with
    	i.e. :php:func:`form_input()` and avoid double-escaping.

	Example::

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

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

.. 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:	'selected' attribute or an empty string
    	:rtype:	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>

.. 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:	'checked' attribute or an empty string
    	:rtype:	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'); ?> />

.. 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:	'checked' attribute or an empty string
    	:rtype:	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.
