Learning Salesforce Lightning Application Development

Unbound expression bindings

Two-way data-binding, using {!v.expression} is expensive on performance. If you do not need to keep your UI in sync with model changes, then prefer one-way data bindings. This can improve the rendering time of the application, since the framework need not maintain event listeners.

The syntax for the unbound expression is as follows:

{#!v.expression}

Let's consider the following example code snippet, where you will need to pass an attribute value from parent to child, using an unbound expression. With one-way binding, notice that any changes to the child attribute are not propagated to the parent. Let's take a look:

<!--c:childExpr--><aura:component>    <aura:attribute name="childAttr" type="String" /> <p>childExpr ...