How to use an if-else condition in a SAPUI5 XML-View?

How can I implement an if-else condition in a XML-View in SAPUI5 that uses a flag (condition) from a JSONModel?

So far I have a Controller:

sap.ui.define([
    "sap/ui/core/mvc/Controller",
    "sap/ui/model/json/JSONModel"
], function (Controller, JSONModel) {
    "use strict";

    return Controller.extend("sap.ui.demo.myApp.myController", {
        onInit: function () {
            //// set data model on view
            var oData = {
                title: "A cool title",
                values: [{name: "Text 1", marketed: true}, {name: "Text 2", marketed: false}, {name: "Text 3", , marketed: true}]
            };

            var oModel = new JSONModel(oData);
            this.getView().setModel(oModel);
        }
    });
});

and a View:

<mvc:View
    controllerName="sap.ui.demo.myApp.myController"
    xmlns="sap.m">

    <!-- using aggregation binding -->
    <Panel expandable="true" expanded="true" headerText="{/title}" width="100%" content="{/values}">
        <content>
            <Label text="{name}"/>
            <!-- if {marketed} 
                    <Label text="product is marketed"/> 
                 else 
                    add nothing
            -->
        </content>
    </Panel>

</mvc:View>

Edit:

Is there a better way to do it than by implementing an overkill-feeling XML-Preprocessor?

Answer

OpenUI5 supports Preprocessing Instructions and Expression Binding.

With Preprocessing Instructions you can do stuff like this:

<template:if test="{marketed}">
    <template:then>
        <Label text="product is marketed" />
    </template:then>
    <template:else>
        <Image src="path.jpg" />
    </template:else>
</template:if>

I am not sure if the test in the first line tests for null/not null or true/false. This is where the Expression Binding might be handy: it allows for complex expressions within the curly brackets:

<template:if test="{= ${marketed} === true}">

---

Edit

The following solution might be more simple, but seems a little hacky.

Embed both elements in your XML view, but toggle the visibility with complex expression binding:

<Label text="product is marketed" visible="{= ${marketed} === true}"/>
<Image src="path.jpg" visible="{= ${marketed} === false}"/>