Meteor blaze, Use helper / variable in Content Blocks (contentFor) - meteor

Question

I have a template (navBarContent) that I is passed a "title" when I insert it.
I am then able to access {{title}} within that template, but it is not possible to access it within a {{#contentFor}} block embedded in the navBarContent template:
<template name="map">
{{>navBarContent title="MAP"}}
... other content ...
<template>
<template name="navBarContent ">
{{title}}
{{#contentFor "headerTitle"}}
<h1 class="title">{{title}}</h1>
{{/contentFor}}
</template>
I already tried to "forward" the title:
<template name="navBarContent ">
{{title}}
{{#contentFor "headerTitle" title="MAP"}}
<h1 class="title">{{title}}</h1>
{{/contentFor}}
</template>
which produces the following error:
First argument must be a function, to be called on the rest of the arguments;
EDIT:
Ok. I think the data scopes are a the following:
<template name="layout">
{{> yield "headerTitleRenderedInLayout"}}
{{> yield}}
</template>
<template name='map'>
{{> yield "headerTitleRenderedInTemplate"}}
{{>navBarContent title="PARAMETER_TITLE"}}
</template>
<template name="navBarContent">
{{title}} <!-- output: PARAMETER_TITLE -->
{{#contentFor "headerTitleRenderedInLayout"}}
<h1 class="title">{{title}}</h1> <!-- output: LAYOUT_DATA_TITLE -->
{{/contentFor}}
{{#contentFor "headerTitleRenderedInTemplate"}}
<h1 class="title">{{title}}</h1> <!-- output: TEMPLATE_DATA_TITLE -->
{{/contentFor}}
</template>
Above outputs are produced when I use the following router options:
Router.route('/map', function () {
this.layout("layout", {
data: function() {
return { title: "LAYOUT_DATA_TITLE" }
}
});
this.render('map', {
data: function() {
return { title: "TEMPLATE_DATA_TITLE" }
}
});
});
My app has a navbar that is defined in my main layout and I therefore need to set the datacontext for the layout in my route. So far so good, but I want to set that data context based on the value that I pass via:
{{>navBarContent title="PARAMETER_TITLE"}}
This is just a cosmetic thing, because I prefer to define my navbar content in the different templates rather than the routes.

Answer 1

It works when you pass the data context to the render function because Iron Router handles the contentFor block:
Router.route('/', function() {
this.render('map', {
data: function() {
return { title: 'MAP' }
}
});
});
Then the following template shows MAP twice:
<template name="map">
{{> navBarContent }}
{{> yield 'anotherBlock'}}
</template>
<template name="navBarContent">
<div>
In "map": {{title}}
</div>
{{#contentFor 'anotherBlock'}}
<div>
In contentFor: {{title}}
</div>
{{/contentFor}}
</template>