magento2 knockoutjs custom template binding

Question

I'm trying to understand knockoutjs in magento2.especially custom template binding.I'm not able to get idea flow of rendering this.

Can any one have idea how it works? atleast Where can I find definition of getTemplate?

<!-- ko if: (!quoteIsVirtual) -->
            <!-- ko foreach: getRegion('customer-email') -->
                <!-- ko template: getTemplate() --><!-- /ko -->
            <!--/ko-->
        <!--/ko-->

Answer 1

Open

Magento/Checkout/view/frontend/layout/checkout_index_index.xml

file. look at following line

<item name="component" xsi:type="string">Magento_Checkout/js/view/shipping</item>

So

Magento/Checkout/view/frontend/web/js/view/shipping.js

this is your js file. Open it. Look

template: 'Magento_Checkout/shipping'

this is the template file for this JS.

Go back to

Magento/Checkout/view/frontend/layout/checkout_index_index.xml

line 122 (M2 2.0.0-rc)

<item name="children" xsi:type="array">

here you can see some child node. like

<item name="customer-email" xsi:type="array">
----
---
</item>

So

getTemplate()

is responsible for current template rendering that means

Magento/Checkout/view/frontend/web/template/form/element/email.html

Open it, then you can see following code snippet

<!-- ko foreach: getRegion('additional-login-form-fields') -->
            <!-- ko template: getTemplate() --><!-- /ko -->
            <!-- /ko -->

this 'additional-login-form-fields' node is the child node of 'customer-email' .

For your code snippet, if quote is not virtual then pick ko

foreach: getRegion('customer-email')

which is child node name and render its template.

Answer 2

You can find defination of getTemplate from,

`root\vendor\magento\module-ui\view\base\web\js\lib\core\element\element.js` 

file from line no. 255 to 257.

  getTemplate: function () {
                return this.template;
            }