Computed observables as helper functions (with declared dependencies, and optional setter)

Change name

HTML:

<!-- data-linking-->

<input data-link="~fullName()" />
...
<td data-link="~fullName(true)" ></td>

<!-- data-bound tag-->

{^{:~fullName(true)}}

Script:

//====================== Data ======================
var person = {
    firstName: "Jeff",
    lastName: "Friedman"
};

//====================== Helper ======================
// Parameterized computed observable helper function
function fullName(reversed) { ... }

// Declare dependencies
fullName.depends = ["#data.firstName", "#data.lastName"];

// For two-way binding of computed observables, provide a setter
fullName.set = function(val) {
    // The this pointer is the view, so this.data is the current data item
    $.observable(this.data).setProperty({
        lastName: ...,
        firstName: ...
    });

//========== Register helper, or pass in as parameter ==========
// Register helper ...
$.views.helpers({
	fullName: fullName
});

// ... or alternatively pass helper in as a computed template parameter:
$.link.personTmpl( "#details", person, { fullName: fullName});