Meteor get ID of template parent - meteor

Question

I have two Collection : a collection A which include array of B ids.
Template A :
<template name="templateA">
Name : {{name}} - {{_id}}
{{#each allBsOfThisA}}
{{> Bdetail}}
{{/each}}
Add B for this A
</template>
Note : in this templateA, I list all A and their detail informations. At bottom of the A, I putted a link to add a B.
Template of Bsubmit :
<div class="form-group {{errorClass 'nameOfB'}}">
<label class="control-label" for="nameOfB">nameOfB</label>
<div class="controls">
<input name="nameOfB" id="nameOfB" type="text" value="" placeholder="nameOfB" class="form-control"/>
<span class="help-block">{{errorMessage 'nameOfB'}}</span>
</div>
</div>
<input type="submit" value="Submit" class="btn btn-primary"/>
On the Bsubmit script : I want to get the ID of A. I tried with template.data._id but it's not working :
Template.Bsubmit.events({'submit form': function(e, template) {
e.preventDefault();
console.log("template.data._id: " + template.data._id);
var B = {
name: $(e.target).find('[name=name]').val(),
AId : template.data._id
};
}
});
EDIT :
BSubmit's iron-router part :
Router.route('Bsubmit ', {name: 'Bsubmit '});

Answer 1

Neither the template nor the route does know about the A-instance of the other template/route.
So one solution would be to pass the id to the route, which allows you to fetch the instance or use the id directly:
Template:
<template name="templateA">
Name : {{name}} - {{_id}}
{{#each allBsOfThisA}}
{{> Bdetail}}
{{/each}}
Add B for this A
</template>
Route:
More information about passing arguments to a route
Router.route('/Bsubmit/:_id', function () {
var a = A.findOne({_id: this.params._id});
this.render('Bsubmit', {data: a});
});
Then you could use template.data._id in the event.
Another solution would be to embed the form into the other view, so you can access the data of the parent template in there (documentation of parentData).