Numerous types of form field are built into Joomla, with many usefull fields like calendar, color picker, image picker, file upload, file selection etc.:
## Available Fields
+---------------------+-------------------------------------------------------------------------------------------------------+
| TYPE | DESCRIPTION |
+---------------------+-------------------------------------------------------------------------------------------------------+
| accesslevel | provides a drop down list of viewing access levels. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| cachehandler | provides a list of available cache handling options. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| calendar | provides a text box for entry of a date. An icon next to the text box |
| | provides a link to a pop-up calendar, which can also be used |
| | to enter the date value. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| captcha | provides a drop down list of the captcha plugins. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| category | provides a drop down list of categories for an extension. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| checkbox | provides a single checkbox to be checked or unchecked |
+---------------------+-------------------------------------------------------------------------------------------------------+
| checkboxes | provides unlimited checkboxes that can be used for multi-select. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| Chrome Style | provides a list of template chrome style options grouped by template. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| color | provides a color picker when clicking the input box. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| Content Language | Provides a list of content languages. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| Content Type | Provides a list of content types. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| combo | provides a combo box field. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| componentlayout | provides a grouped list of core and template alternate layouts |
| | for a component item. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| contentlanguage | provides a list of installed content languages for use in |
| | conjunction with the language switcher plugin. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| Database Connection | Provides a list of available database connections, |
| | optionally limiting to a given list. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| editor | provides an editor area field. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| editors | Provides a drop down list of the available WYSIWYG editors. |
| | Since Joomla 2.5 use plugins form field instead. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| email | provides an email field. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| file | |
+---------------------+-------------------------------------------------------------------------------------------------------+
| filelist | provides a drop down list of files from a specified directory. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| folderlist | provides a drop down list of folders from a specified directory. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| groupedlist | provides a drop down list of items organized into groups. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| header tag | provides a drop down list of the header tags (h1-h6). |
+---------------------+-------------------------------------------------------------------------------------------------------+
| helpsite | provides a drop down list of the help sites for your Joomla installation. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| hidden | provides a hidden field for saving a form field whose value cannot be altered directly |
| | by a user in the Administrator (it can be altered in code or by editing the params.ini file). |
+---------------------+-------------------------------------------------------------------------------------------------------+
| imagelist | provides a drop down list of image files in a specified directory. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| integer | provides a drop down list of integers between a minimum and maximum. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| language | provides a drop down list of the installed languages for the Front-end or Back-end. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| list | provides a drop down list of custom-defined entries. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| media | provides modal access to the media manager for insertion of images with |
| | upload for users with appropriate permissions. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| menu | provides a drop down list of the available menus from your Joomla site. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| Menu Item | provides a drop down list of the available menu items from your Joomla site. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| Module Layout | provides a list of alternative layout for a module grouped by core and template. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| Module Order | Provides a drop down to set the ordering of module in a given position |
+---------------------+-------------------------------------------------------------------------------------------------------+
| Module Position | provides a text input to set the position of a module. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| Module Tag | provides a list of html5 elements (used to wrap a module in). |
+---------------------+-------------------------------------------------------------------------------------------------------+
| note | supports a one line text field. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| password | provides a text box for entry of a password. |
| | The password characters will be obscured as they are entered. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| plugins | provides a list of plugins from a given folder. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| radio | provides radio buttons to select different options. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| repeatable | Allows form fields which can have as many options as the user desires. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| rules | provides a matrix of group by action options for managing access control. Display depends on context. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| sessionhandler | provides a drop down list of session handler options. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| spacer | provides a visual separator between form fields. It is purely a visual aid and no value is stored. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| sql | provides a drop down list of entries obtained by running a query on the Joomla Database. |
| | The first results column returned by the query provides the values for the drop down box. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| tag | provides an entry point for tags (either AJAX or Nested). |
+---------------------+-------------------------------------------------------------------------------------------------------+
| tel | provides an input field for a telephone number. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| templatestyle | provides a drop down list of template styles. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| text | provides a text box for data entry. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| textarea | provides a text area for entry of multi-line text. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| timezone | provides a drop down list of time zones. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| URL | provides a URL text input field. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| user | provides a modal list of users. |
+---------------------+-------------------------------------------------------------------------------------------------------+
| usergroup | provides a drop down list of user groups. |
+---------------------+-------------------------------------------------------------------------------------------------------+
The complete list with examples can be found at [http://docs.joomla.org/Form_field][1].
## Example usage
This example XML file with (almost) all available fields might be useful in order to see all available fields and how they look:
<?xml version="1.0" encoding="UTF-8"?>
<extension version="2.5" type="module" client="site" method="upgrade">
<name>All fields Demo</name>
<description>XML file containing all available form fields in Joomla</description>
<files>
<filename module="mod_AllFields">mod_AllFields.php</filename>
</files>
<config>
<fields name="params">
<fieldset name="basic">
<field name="access" type="accesslevel" label="JFIELD_ACCESS_LABEL" description="JFIELD_ACCESS_DESC" class="span12 small" />
<field name="cache_handler" type="cachehandler" default="" label="Cache Handler Field type" description="COM_CONFIG_FIELD_CACHE_HANDLER_DESC" filter="word" />
<field name="mycalendar" type="calendar" default="5-10-2008" label="Select a date" description="" format="%d-%m-%Y" />
<field name="captcha" type="plugins" folder="captcha" label="Captcha Selection field" description="COM_CONTACT_FIELD_CAPTCHA_DESC" default="" filter="cmd">
<option value="">JOPTION_USE_DEFAULT</option>
<option value="0">JOPTION_DO_NOT_USE</option>
</field>
<field name="mycategory" type="category" extension="com_content" label="Select a category" description="" />
<field name="show_title" type="checkbox" label="Show title" description="Show the title of the item" value="1" />
<field name="toppings" type="checkboxes">
<option value="anch">Anchovies</option>
<option value="chor">Chorizo</option>
<option value="on">Onions</option>
<option value="mush">Mushrooms</option>
</field>
<field name="style" type="chromestyle" label="COM_MODULES_FIELD_MODULE_STYLE_LABEL" description="COM_MODULES_FIELD_MODULE_STYLE_DESC" />
<field name="backgroundcolor" type="color" default="#eee" label="Color selector field" description="TPL_BEEZ3_FIELD_HEADER_BACKGROUND_COLOR_DESC" />
<field name="types" type="contenttype" label="Tags field type" description="COM_TAGS_FIELD_TYPE_DESC" multiple="true" />
<field name="myeditbox" type="combobox" label="MyEditBox" description="myeditbox_Desc" size="7" />
<field name="mylayout" type="componentlayout" extension="com_content" view="article" label="Component Layout field" useglobal="true" description="JFIELD_ALT_COMPONENT_LAYOUT" />
<field name="language" type="contentlanguage" label="JFIELD_LANGUAGE_LABEL" description="COM_CATEGORIES_FIELD_LANGUAGE_DESC" class="span12 small">
<option value="*">JALL</option>
</field>
<field name="dbtype" type="databaseconnection" label="DB type field" description="COM_CONFIG_FIELD_DATABASE_TYPE_DESC" supported="mysql,mysqli,postgresql,sqlsrv,sqlazure" filter="string" />
<field name="test1" label="Test Field" type="editor" width="300" filter="safehtml" />
<field name="email" type="email" label="JGLOBAL_EMAIL" description="COM_ADMIN_USER_FIELD_EMAIL_DESC" required="true" size="30" class="inputbox" validate="email" />
<field name="myfilevalue" type="file" label="Enter some text" description="Choose an image from your computer with maximum 100KB" size="10" accept="image/*" />
<field name="myfile" type="filelist" default="" label="Select a file" description="" directory="administrator" filter="" exclude="" stripext="" />
<field name="myfolder" type="folderlist" default="" label="Select a folder" directory="administrator" filter="" exclude="" stripext="" />
<field name="mylistvalue" type="groupedlist" default="" label="Select an option" description="">
<group label="Group 1">
<option value="0">Option 1</option>
<option value="1">Option 2</option>
</group>
<group label="Group 2">
<option value="3">Option 3</option>
<option value="4">Option 4</option>
</group>
<option value="5">Option 5</option>
<option value="6">Option 6</option>
</field>
<field name="header_tag" type="headertag" label="COM_MODULES_FIELD_HEADER_TAG_LABEL" description="COM_MODULES_FIELD_HEADER_TAG_DESC" default="h3" />
<field name="myhelpsite" type="helpsite" default="" label="Select a help site" description="" />
<field name="mysecretvariable" type="hidden" default="" />
<field name="myimage" type="imagelist" default="" label="Select an image" description="" directory="" exclude="" stripext="" />
<field name="myintegervalue" type="integer" default="Some integer" label="Choose an integer" description="" first="1" last="10" step="1" />
<field name="mylanguage" type="language" client="site" default="en-GB" label="Select a language" description="" />
<field name="mylistvalue" type="list" default="" label="Select an option" description="">
<option value="0">Option 1</option>
<option value="1">Option 2</option>
</field>
<field name="myimage" type="media" directory="stories" />
<field name="mymenu" type="menu" default="mainmenu" label="Select a menu" description="Select a menu" />
<field name="mymenuitem" type="menuitem" default="45" label="Select a menu item" description="Select a menu item" />
<field name="mymodulelayout" type="modulelayout" label="JFIELD_ALT_LAYOUT_LABEL" description="JFIELD_ALT_MODULE_LAYOUT_DESC" />
<field name="ordering" type="moduleorder" label="JFIELD_ORDERING_LABEL" description="JFIELD_ORDERING_DESC" />
<field name="position" type="moduleposition" description="COM_MODULES_FIELD_POSITION_DESC" label="COM_MODULES_FIELD_POSITION_LABEL" default="" maxlength="50" />
<field name="module_tag" type="moduletag" label="COM_MODULES_FIELD_MODULE_TAG_LABEL" description="COM_MODULES_FIELD_MODULE_TAG_DESC" default="div" />
<field name="note31" type="note" class="alert" close="true" label="Note Field" description="Note field description here." />
<field name="mypassword" type="password" default="secret" label="Enter a password" description="" size="5" />
<field name="editor" type="plugins" folder="editors" description="COM_USERS_USER_FIELD_EDITOR_DESC" label="User editor field type">
<option value="">JOPTION_USE_DEFAULT</option>
</field>
<field name="myradiovalue" type="radio" default="0" label="Select an option" description="">
<option value="0">1</option>
<option value="1">2</option>
</field>
<field name="session_handler" type="sessionhandler" default="none" label="Session handler field type" description="COM_CONFIG_FIELD_SESSION_HANDLER_DESC" required="true" filter="word" />
<field type="spacer" name="myspacer" label="Spacer field type" />
<field name="title" type="sql" default="10" label="sql Field type" query="SELECT id AS value, title FROM #__content" />
<field name="tags" type="tag" label="JTAG" description="JTAG_DESC" mode="ajax" class="inputbox span12 small" multiple="true" />
<field name="admin_style" type="templatestyle" client="administrator" description="Template style field type" label="Template style field type">
<option value="">JOPTION_USE_DEFAULT</option>
</field>
<field name="mytextvalue" type="text" default="Some text" label="Enter some text" description="" size="10" />
<field name="mytextarea" type="textarea" default="default" label="Enter some text" description="" rows="10" cols="5" />
<field name="mytimezone" type="timezone" default="-10" label="Select a timezone" description="" />
<field name="mytextvalue" type="url" default="http://www.example.com" label="Enter a URL" description="" size="10" />
<field name="modified_user_id" type="user" label="JGLOBAL_FIELD_MODIFIED_BY_LABEL" class="readonly" readonly="true" filter="unset" />
<field name="guest_usergroup" type="usergroup" label="Guest usergroup field type" description="COM_USERS_CONFIG_FIELD_GUEST_USER_GROUP_DESC" multiple="true" />
</fieldset>
</fields>
</config>
</extension>
*Note that some of the fields are only available in Joomla 3.0 (or 3.1, in the case of `contentType`, `note` and `tag`).*
## Custom form field types
An extension can define its own form field types, which can then be used in its own forms or forms created by another extension. See [Creating a custom form field type][2] (Joomla! Documentation) for instructions.
[1]: http://docs.joomla.org/Form_field
[2]: http://docs.joomla.org/Creating_a_custom_form_field_type