Jifty::Web::Form::Element(3)

NAME
Jifty::Web::Form::Element - Some item that can be rendered in a form

DESCRIPTION
Describes any HTML element that might live in a form, and thus might have javascript on it.

Handlers are placed on Jifty::Web::Form::Element objects by calling the name of the javascript event handler, such as "onclick" or "onchange", with a set of arguments.

The format of the arguments passed to "onclick" (or any similar method) is a string, a hash reference, or a reference to an array of multiple hash references. Strings are inserted verbatim.

Hash references can take a number of possible keys. The most important is the mode of the fragment replacement, if any; it is specified by providing at most one of the following keys:

append => PATH
    Add the given "PATH" as a new fragment, just before the close of the CSS selector given by "element", which defaults to the end of the current region.

prepend => PATH
    Add the given "PATH" as a new fragment, just after the start of the CSS selector given by "element", which defaults to the start of the current region.

replace_with => PATH
    Replaces the region specified by the "region" parameter (which defaults to the current region) with the fragment located at the given "PATH". If "undef" is passed as the "PATH", acts like a "delete".

refresh => REGION
    Refreshes the given "REGION", which should be a Jifty::Web::PageRegion object, or the fully qualified name of such.

refresh_self => 1
    Refreshes the current region; this is the default action, if a non-empty "args" is supplied, but no other mode is given.

delete => REGION
    Removes the given "REGION" from the page, permanently.

The following options are also supported:

toggle => BOOLEAN
    If set to true, then the link will possibly toggle the region to empty, if the region's current path is the same as the path the region is trying to be set to.

region => REGION
    The region that should be updated. This defaults to the current region.

element => CSS SELECTOR
    A css selector specifying where the new region should be placed; used with "append" and "prepend", above. The "get_element" in Jifty::Web::PageRegion method may be useful in specifying elements of parent page regions.

submit => MONIKER
    A Jifty::Action, Jifty::Action moniker, hashref of
        { action => Jifty::Action::Subclass,
         arguments => { argument => value, argument2 => value2 }

    or an arrayref of them.

    These actions are submitted when the event is fired. Any arguments specified will override arguments submitted by form field.

    If you explicitly pass "undef", then all actions will be submitted. This can be useful in conjunction with an "onclick" handler, since declaring an "onclick" handler inentionally turns off action submission.

disable => BOOLEAN
    If true, disable all form fields associated with the actions in "submit" when this Element is clicked. This serves to give immediate visual indication that the request is being processed, as well as to prevent double-submits.

    Defaults to true.

args => HASHREF
    Arguments to the region. These will override the arguments to the region that the region was given when it was last rendered.

effect => STRING
    The Scriptaculous or jQuery visual effect to use when updating or creating the fragment.

effect_args => HASHREF
    A hashref of arguments to pass to the effect when it is created. These can be used to change the duration of the effect, for instance.

remove_effect => STRING
    As "effect", but for when the previous version of the region is removed.

remove_effect_args => HASHREF
    As "effect_args", but for "remove_effect".

beforeclick => STRING
    String contains some Javascript code to be used before a click.

confirm => STRING
    Prompt the user with a Javascript confirm dialog with the given text before carrying out the rest of the handlers. If the user cancels, do nothing, otherwise proceed as normal.

    TODO: This does not have a non-Javascript fallback method yet.

  handlers
The following handlers are supported:

onclick onchange ondblclick onmousedown onmouseup onmouseover onmousemove onmouseout onfocus onblur onkeypress onkeydown onkeyup onselect

NOTE: onload, onunload, onsubmit and onreset are not yet supported

WARNING: if you use the onclick handler, make sure that your javascript is "return (function name);", or you may well get a very strange-looking error from your browser.

  accessors
Any descendant of Jifty::Web::Form::Element should be able to accept any of the event handlers (above) as one of the keys to its "new" parameter hash.

  new PARAMHASH OVERRIDE
Create a new "Jifty::Web::Form::Element" object blessed with PARAMHASH, and set with accessors for the hash values in OVERRIDE.

  onclick
The onclick event occurs when the pointing device button is clicked over an element. This attribute may be used with most elements.

  onchange
The onchange event occurs when a control loses the input focus and its value has been modified since gaining focus. This handler can be used with all form elements.

  ondblclick
The ondblclick event occurs when the pointing device button is double clicked over an element. This handler can be used with all form elements.

  onmousedown
The onmousedown event occurs when the pointing device button is pressed over an element. This handler can be used with all form elements.

  onmouseup
The onmouseup event occurs when the pointing device button is released over an element. This handler can be used with all form elements.

  onmouseover
The onmouseover event occurs when the pointing device is moved onto an element. This handler can be used with all form elements.

  onmousemove
The onmousemove event occurs when the pointing device is moved while it is over an element. This handler can be used with all form elements.

  onmouseout
The onmouseout event occurs when the pointing device is moved away from an element. This handler can be used with all form elements.

  onfocus
The onfocus event occurs when an element receives focus either by the pointing device or by tabbing navigation. This handler can be used with all form elements.

  onblur
The onblur event occurs when an element loses focus either by the pointing device or by tabbing navigation. This handler can be used with all form elements.

  onkeypress
The onkeypress event occurs when a key is pressed and released over an element. This handler can be used with all form elements.

  onkeydown
The onkeydown event occurs when a key is pressed down over an element. This handler can be used with all form elements.

  onkeyup
The onkeyup event occurs when a key is released over an element. This handler can be used with all form elements. =cut

  onselect
The onselect event occurs when a user selects some text in a text field. This attribute may be used with the text and textarea fields.

  _handler_setup
This method is used by all handlers to normalize all arguments.

  handlers_used
Returns the names of javascript handlers which exist for this element.

  javascript
Returns the javascript necessary to make the events happen, as a string of HTML attributes.

  javascript_attrs
Returns the javascript necessary to make the events happen, as a hash of attribute-name and value.

  javascript_preempt
Returns true if the the javascript's handlers should prevent the web browser's standard effects from happening; that is, for "onclick", it prevents buttons from submitting and the like. The default is to return true, but this can be overridden.

  class
Sets the CSS class that the element will display as

  title
Sets the title that the element will display, e.g. for tooltips

  key_binding
Sets the key binding associated with this element

  key_binding_label
Sets the key binding label associated with this element (if none is specified, the normal label is used instead)

  id
Subclasses must override this to provide each element with a unique id.

  label
Sets the label of the element. This will be used for the key binding legend if key_binding_label is not set.

  key_binding_javascript
Returns the javascript fragment to add key binding for this input, if one exists.

  render_key_binding
Renders the javascript from "key_binding_javscript" in a <script> tag, if needed.

  handler_allowed HANDLER_NAME
Returns 1 if the handler (e.g. onclick) is allowed. Undef otherwise.

The set defined here represents the typical handlers that are permitted. Derived classes should override if they stray from the norm.

By default we allow:

onchange onclick ondblclick onmousedown onmouseup onmouseover onmousemove onmouseout onfocus onblur onkeypress onkeydown onkeyup