ViewModel-less compose with model.bind in aurelia - aurelia

Question

I am having a structure where the main view composes a partial view that composes another partial view in a repeater.
Example:
main view
<template>
<h1>${factory.name}</h1>
<div class="column">
<compose view="./cars.html"></compose>
</div>
</template>
cars view
<template repeat.for="car of factory.cars">
<compose view="./specifications.html model.bind="{test: 'abc}"></compose>
</template>
specifications view
<template repeat.for="car of factory.cars">
<h1>${$parent.$parent.factory.name} - ${car.name}</h1>
${test}
</template>
The problem I am facing is that the model.bind in compose doesn't work. I tried it with the test above, but what I'd actually want to pass there is $parent.$parent.factory so I can output $parent.$parent.factory.name in the specifications view.
(I know I can print it like this, but the scenario gets way more complicated so
the binding is necessary)
Worth to mention that both specifications and cars view are viewmodel-less. Only themain view has a viewmodel where factory and cars are coming from.
According to this page, what I am trying to do is possible, but I can't wrap my head about what I'm doing wrong.

Answer 1

When composing with just an html file, the view-model for the referenced html file is the same as where the compose element is placed. In other words, it inherits the view-model of the parent. So you don't need to supply the model.
main view
<template>
<h1>${factory.name}</h1>
<div>
<compose view="./cars.html"></compose>
</div>
</template>
cars.html
<template>
<div repeat.for="car of factory.cars">
<compose view="./specifications.html"></compose>
</div>
</template>
specifications.html
<template>
<h1>${factory.name} - ${car.name}</h1>
</template>
Take a look at this GistRun example.

Answer 2

What #Jeff G said is correct, but for my specific use-case what solved my issue was creating a simple view-model that I could use for all compositions. It's looking like:
export class Main {
public parentFactory;
public activate(data) {
this.parentFactory= data;
}
}
And in the view
<compose
view="./car.html"
view-model="../view-models/main"
model.bind="$parent.$parent.factory">
</compose>