To produce updates, each line of html produced by a "do" sequence in the Widget monad is included within a span tag. When the line is reexecuted after a event, the span is updated with the new rendering.

static tell to the rendering that this widget does not change, so the extra span tag for each line in the sequence and the rewriting is not necessary. Thus the size of the HTML and the performance is improved.

It is a callback in the view monad. The rendering of the second parameter substitutes the rendering of the first paramenter when the latter validates without afecting the rendering of other widgets. This allow the simultaneous execution of different dynamic behaviours in different page locations at the same page.

Join two widgets in the same page the resulting widget, when asked with it, return a 2 tuple of their validation results if both return Noting, the widget return Nothing (invalid).

it has a low infix priority: infixr 2

r <- ask  widget1 <+>  widget2
case r of (Just x, Nothing) -> ..

The first elem result (even if it is not validated) is discarded, and the secod is returned . This contrast with the applicative operator *> which fails the whole validation if the validation of the first elem fails.

The first element is displayed however, as happens in the case of *> .

Here w's are widgets and r's are returned values

(w1 <* w2) will return Just r1 only if w1 and w2 are validated

(w1 <** w2) will return Just r1 even if w2 is not validated

it has a low infix priority: infixr 1

The second elem result (even if it is not validated) is discarded, and the first is returned . This contrast with the applicative operator *> which fails the whole validation if the validation of the second elem fails. The second element is displayed however, as in the case of <*. see the <** examples

it has a low infix priority: infixr 1

Validates a form or widget result against a validating procedure

getOdd= getInt Nothing validate (x -> return $ if mod x 2==0 then  Nothing else Just "only odd numbers, please")

Concat a list of widgets of the same type, return a the first validated result

from a list of widgets, it return the validated ones.

like manyOf, but does not validate if one or more of the widgets does not validate

Enclose Widgets within some formating. view is intended to be instantiated to a particular format

NOTE: It has a infix priority : infixr 5 less than the one of ++> and <++ of the operators, so use parentheses when appropriate, unless the we want to enclose all the widgets in the right side. Most of the type errors in the DSL are due to the low priority of this operator.

A parameter application with lower priority than ($) and direct function application

Append formatting code to a widget

 getString "hi" <++ H1 << "hi there"

It has a infix prority: infixr 6 higuer that <<< and most other operators

Prepend formatting code to a widget

bold "enter name" ++ getString Nothing

It has a infix prority: infixr 6 higuer that <<< and most other operators

Add attributes to the topmost tag of a widget

it has a fixity infix 8

show something enclosed in the pre tag, so ASCII formatting chars are honored

Display a text box and return a non empty String

Display a text box and return an Integer (if the value entered is not an Integer, fails the validation)

Display a text box and return a Int (if the value entered is not an Int, fails the validation)

Display a password box

Implement a radio button the parameter is the name of the radio group

encloses a set of Radio boxes. Return the option selected

Display a text box and return the value entered if it is readable( Otherwise, fail the validation)

Display a multiline text box and return its content

A synonim of getMultilineText

Display a dropdown box with the options in the first parameter is optionally selected . It returns the selected option.

Set the option for getSelect. Options are concatenated with <|>

Set the selected option for getSelect. Options are concatenated with <|>

active button. When clicked, return the label value

Present a link. Return the first parameter when clicked

Empty widget that does not validate. May be used as "empty boxes" inside larger widgets.

It returns a non valid value.

a sinonym of noWidget that can be used in a monadic expression in the View monad. it stop the computation in the Widget monad.

Render a Show-able value and return it wrender :: (Monad m, Functor m, Show a,Monad (View view m), FormInput view) => a -> View view m a wrender x = (fromStr $ show x) ++> return x

Render raw view formatting. It is useful for displaying information.

True if the widget has no valid input

Run the widget as the content of the element with the given id. The content can be appended, prepended to the previous content or it can be the only content depending on the update method.

Get the session data of the desired type if there is any.

getSessionData specialized for the View monad. if Nothing, the monadic computation does not continue. getSData is a widget that does not validate when there is no data of that type in the session.

setSessionData :: (StateType m ~ MFlowState, Typeable a) => a -> m ()

a shorter name for setSessionData

triggers the event when it happens in the widget.

What happens then?

1)The event reexecutes all the monadic sentence where the widget is, (with no re-rendering)

2) with the result of this reevaluaution, executes the rest of the monadic computation

3) update the DOM tree with the rendering of the reevaluation in 2).

As usual, If one step of the monadic computation return empty, the reevaluation finish So the effect of an event can be restricted as much as you may need.

Neither the computation nor the tree in the upstream flow is touched. (unless you use out of stream directives, like at)

monadic computations inside monadic computations are executed following recursively the steps mentioned above. So an event in a component deep down could or could not trigger the reexecution of the rest of the whole.

A shorter synonym for raiseEvent

A shorter and smoother synonym for raiseEvent

A professional synonym for raiseEvent

pass trough only if the event is fired in this DOM element. Otherwise, if the code is executing from a previous event, the computation will stop

return empty and the monadic computation stop if the condition is false. If true, return the second parameter.

executes a widget each t milliseconds until it validates and return ()

run the widget as the content of a DOM element the new rendering is added to the element

run the widget as the content of a DOM element, the id is passed as parameter. All the content of the element is erased previously and it is substituted by the new rendering

run the widget as the body of the HTML

add a header in the header tag

get the next ideitifier that will be created by genNewId

Generate a new string. Useful for creating tag identifiers and other attributes.

if the page is refreshed, the identifiers generated are the same.

Minimal interface for defining the basic form and link elements. The core of MFlow is agnostic about the rendering package used. Every formatting (either HTML or not) used with MFlow must have an instance of this class. See "MFlow.Forms.Blaze.Html for the instance for blaze-html" MFlow.Forms.XHtml for the instance for Text.XHtml and MFlow.Forms.HSP for the instance for Haskell Server Pages.