Wrapper around HTML Forms
Class GvaScript.Form - Wrapper around HTML Forms
<form id="my_form" onsubmit="return false;"> <div repeat="foo"> <h2>Foo #{foo.count}</h2> <input type="text" name="person.name"/> <input type="text" name="person.bdate"/> This is the repeated foo section <table> <tr repeat="bar"> <td>Item #{bar.count}</td> <td><input name="#{bar.path}.buz"></td> <td><button onclick="GvaScript.Form.remove('#{bar.path}')"> Remove this row </button></td> </tr> </table> <button onclick="GvaScript.Form.add('#{foo.path}.bar')"> Add a bar </button> </div> <button onclick="GvaScript.Form.add('foo')">Add a foo</button> </form> <script> var gvascript_form = new GvaScript.Form('my_form', { datatree: {name:'kitty', bdate:'01.01.1990'}, dataprefix: 'person', // 'active' form elements registry: [ ['input', 'mouseover', function(event) {}], ['input', 'mouseout', function(event) {}], ['input', 'change', function(event, newv ,oldv) {}], ['input', 'init', function(event, newv) {}] ], // handlers to form's custom events onInit: function(gva_form) {}, onRepeatBlockRemove: function(gva_form, arg) { arg[0] // removed repeat name arg[1] // removed repeat path }, onRepeatBlockAdd: function(gva_form, arg) { arg[0] // added repeat name arg[1] // added repeat path }, onChange: function(gva_form, event) { // event.target -> element changed // event.memo.oldvalue -> changed element's old value // event.memo.newvalue -> changed element's new value }, onSubmit: function(gva_form) { // .... // do form submission // .... if(success) {gva_form.fire('AfterSubmit', arg)} else if(data_validation_error) {gva_form.fire('DataValidationError', arg)} else {gva_form.fire('SubmitFailure', arg)} }, onAfterSubmit: function(gva_form, arg) {}, onDataValidationError: function(gva_form, arg) {}, onSubmitFailure: function(gva_form, arg) {}, onBeforeDestroy: function(gva_form, arg) {} } </script>
This module of Alien::GvaScript manages forms with hierarchical fields and dynamically repeated sections. It works in close collaboration with Alien::GvaScript::Repeat.
The design is partially inspired by the Web Forms 2.0
proposal
(http://www.whatwg.org/specs/web-forms/current-work/), but is
not an attempt to implement the proposed specification: there are
some differences both in syntax and in semantics.
new GvaScript.Form(form_id[, options])
id of the HTML form to extend
hash of optional properties that would define the behavior of the form
tree represention of the initial form data.
Ex:
{ name: 'barbie', age: '49', friends: [ { name: 'ken', age: '35' }, { name: 'jen', age: '55' } ] }
sometimes it's helpful to prefix the html input names to give them 'context'.
Ex: doll.name
doll.friends.0.name
.
in this example, the dataprefix should be set to 'doll'
a list of arrays [expression, eventName, handler]
.
each item in the array would be passed over to the /notify method.
function to be called after the successful initialization of the GvaScript.Form instance.
function to be called after a block in a repeated section is removed
Signature
function onRepeatBlockRemove(gva_form, arg) { // gva_form : GvaScript.Form instance // arg: array containing repeat name as first element and repeat path as second }
function to be called after a block in a repeated section is added
Signature
function onRepeatBlockAdd(gva_form, arg) { // gva_form : GvaScript.Form instance // arg: array containing repeat name as first element and repeat path as second }
function to be called when any of the form's elements has changed or onAdd/onRemove of a repeatable section.
Signature
function onChange(gva_form, event) { // gva_form : GvaScript.Form instance // event: Event object fired by the change on the form element // Has a memo object that has olvalue and newvalue set unless // called from the Repeat module }
function to be called directly before the form submits.
Signature
function onBeforeSubmit(gva_form) { // gva_form : GvaScript.Form instance // return false if you want to stop the form from submitting }
function to be called when the form is submit.
Signature
function onSubmit(gva_form) { // gva_form : GvaScript.Form instance // use to fire 'onAfterSubmit', 'onSubmitFailure' or 'onDataValidationError' }
function to be called right before the form instance calls the destroy method.
Callback useful for doing some inhouse cleaning before the form gets removed from the DOM.
Event handlers for custom form events. The form instance should fire these events so as corresponding handler can be fired.
initializes and instance of Alien::GvaScript::ActionsBar.
Signature
actionsbar : { container : 'container_id', actions : [ { label : 'Submit Form', type : 'submit' }, { label : 'Init Form', type : 'button', callback : function() { // 'this' correspond to the button GvaScript.Form.init('form', datatree); } } ] }
Repeat elements may occur outside of forms and therefore are described in a separate document; see Alien::GvaScript::Repeat.
The /init method inspects all form elements for an
autofocus
attribute; the first element that possesses
this attribute automatically receives focus.
Similarly, when a repetition block is added into
the form through the /add method, the first
element within that repetition block that possesses
an autofocus
attribute automatically receives focus.
gvascript_form.destroy()
instance destructor - will unregister the GvaScript.Form instance from the GvaScript.Forms namespace and will remove all of its observers.
gvascript_form.getId()
returns the id of the form element that the gvascript_form instance is wrapped around.
gvascript_form.fire(eventName[, arg])
used to fire event on the for instance and thus called corresponding responders and instance callback.
eventName
: eventName to fire without the 'on' prefix.
arg
argument to send over to the corresponding responder(s) and callback.
this method will
execute the early responders set the on[eventName]
execute instance on[eventName] callback
execute the responders set the on[eventName]
execution sequence will stop whenever one of the responders or callback returns false
NOTE that the onBeforeSubmit, onSubmit events cannot be notified programatically. You actually need to call form.submit() for these events to be fired.
gvascript_form.register(expression, eventName, handler) GvaScript.Form.register(form, expression, eventName, handler)
tells the form to watch the eventName on elements that match the expression and to fire the corresponding handler.
expression
(String) - A css selector
eventName
(String) - The name of the event, in all lower case, without the "on" prefix e.g., "click" (not "onclick").
A custom "init" event is also supported which is fired on an input that gets its value initialized with the initialization of the form.
handler
(Function) - handler to fire.
Signature
function handler(event[, newValue[, oldValue]]) { event.target // element being observed }
newValue
is set for the change
and the init
events.
oldValue
is set for the change
.
NOTE: Form.Element.setValue method is wrapped in GvaSript?.ProtoExtensions module to programatically fire the blur event after setting the value on the input, and hence firing the change handler if any.
[This method can be called either as an instance method or as a generic method. If calling as a generic, pass the form HTMLElement/id in as the first argument.]
gvascript_form.unregister(expression[, eventName[, handler]]) GvaScript.Form.unregister(form, expression[, eventName[, handler]])
removes observers set on given expression
. if eventName
is provided, will only stop observing that eventName.
if handler
is also provided, will just stop calling this handler.
NOTE that the same handler signature should be used in the register method for it to work in the unregister method.
[This method can be called either as an instance method or as a generic method. If calling as a generic, pass the form HTMLElement/id in as the first argument.]
gvascript_form.init(initial_tree, prefix) GvaScript.Form.init(form, initial_tree, prefix)
form
is the id of a form (or directly the DOM element). Optional
initial_tree
is a javascript nested datastructure containing
initial values for fields, that will be passed to the
/fill_from_tree method.
[This method can be called either as an instance method or as a generic method. If calling as a generic, pass the form HTMLElement/id in as the first argument.]
var flat_hash = GvaScript.Form.to_hash(form);
Inspects the contents of all fields in form
and
returns a flat hash of pairs (key-value).
[This method can be called either as an instance method or as a generic method. If calling as a generic, pass the form HTMLElement/id in as the first argument.]
var tree = GvaScript.Form.to_tree(form);
Inspects the contents of all fields in form
and
returns a data tree, were dotted names in form names
are expanded into sub-arrays or sub-hashes. So for example
if the form looks like
<input name="father.firstname"> <input name="father.lastname"><br> <input name="mother.firstname"> <input name="mother.lastname"><br> <div repeat="child" repeat-start="1"> <input name="#{child.path}.firstname"><br> </div>
and if that form has been expanded with 3 repetition blocks for children, the resulting tree would be
{ "father" : {"firstname" : ..., "lastname": ...}, "mother" : {"firstname" : ..., "lastname": ...}, "child" : [ {"firstname": ...}, {"firstname": ...}, {"firstname": ...} ] }
[This method can be called either as an instance method or as a generic method. If calling as a generic, pass the form HTMLElement/id in as the first argument.]
GvaScript.Form.fill_from_tree(form, field_prefix, tree);
Fills the form from values found in tree
(this is the
reverse of the /to_tree operation).
Optional field_prefix
is prepended to key names in tree
for
finding the corresponding form fields.
The method walks through nested subtrees in tree
: the sequence
of keys leading to a leaf is concatenated into a flat string, with dot
separators, and if the form has a corresponding input element,
the value of that element is set to the value of the leaf.
Furthermore, if the initial tree contains repeated data sets
(array subtrees), and if the form contains repeat elements
with the same path, then new repetition blocks are
dynamically created to match the number of items in the array:
so if the form above is filled with the following tree
{ "child" : [ {"firstname": "Abel"}, {"firstname": "Bob"}, {"firstname": "Cod"}, {"firstname": "Dave"}, ] }
then four repetition blocks will automatically created in the form.
[This method can be called either as an instance method or as a generic method. If calling as a generic, pass the form HTMLElement/id in as the first argument.]
GvaScript.Form.add(repeat_name, count);
Creates one or several new repetition blocks. The parameter count
is optional and defaults to 1. Focus is automatically given to the
first input element in the last repetition block that has an
autofocus
attribute (if any).
See Alien::GvaScript::Repeat/add for more explanations on
the add
operation.
GvaScript.Form.remove(repeat_block[, live_update]);
Removes a repetition block from the DOM. The argument is either a DOM element or a string containing the element id.
param Boolean
live_update: flag to indicate whether the 'remaining'
repeatable sections are to be also removed from DOM, recreated by re-merging
the data with repeat template, then finally re-appended to the DOM.
Default true.
All repetition blocks above the removed block are renumbered, leaving no hole in the index sequence. To do so, these blocks are also removed from the DOM, and then added again through the /add method. This operation is implemented by Alien::GvaScript::Repeat/remove.
The recreated blocks are then re-populated with their previous input values.
GvaScript.Form.autofocus(element);
Inspects DOM children of element
, and gives focus to the
first child that has an autofocus
attribute.
namespace that holds all active instances of GvaScript.Form
instances are unique per form id
GvaScript.Forms.get(id)
finds and returns the GvaScript.Form instance where id is the unique id of the form HTMLElement.
A repository of global listeners notified about every step of the GvaSript.Form lifecycle.
Sometimes, you need to provide generic behaviors over all GvaScript.Form(s) in a single application.
To achieve this, GvaScript.Form provides global Responders that will be executed for every GvaScript.Form instance.
Responders by default are executed after the instance specific event callback.
GvaScript.Form.Responders.register({eventName: handler}[, {eventName: handler}[, ...]]})
adding one or more global form events responders.
Supported eventNames: onInit, onChange, onBeforeSubmit, onSubmit, on[XXX]
where on[XXX]
is a custom event name.
GvaScript.Form.Responders.unregister({eventName: handler}[, {eventName: handler}[, ...]]})
unregistering one or more global form events responders.
Identical to GvaScript.Form.Responders except that these responders would be executed before the instance specific callback.