how to make a meteor template helper re-run/render after another template has rendered?

Question

I have a template helper called {{renderNav}} in a template Nav

e.g.

Template.Nav.renderNav

and within that helper function I want

Answer 1

You need a dependency in the template that you want to rerun. There are few possibilities, depending on what data you want to get.

For example, you can set a reactive marker in the content template that will notify renderNav that it's done with drawing.

Template.contentWidnow.rendered = function() {
    ...

    // Set this on the very end of rendered callback.
    Session.set('contentWindowRenderMark', '' +
        new Date().getTime() +
        Math.floor(Math.random() * 1000000) );
}


Template.renderNav.contentData = function() {
    // You don't have to actually use the mark value,
    // but you need to obtain it so that the dependency
    // is registered for this helper.
    var mark = Session.get('contentWindowRenderMark');

    // Get the data you need and prepare for displaying
    ...
}

 

---

 

With further information you've provided, we can create such code:

content.js

Content = {};
Content._dep = new Deps.Dependency;

contentWindow.js

Template.contentWidnow.rendered = function() {
    Content.headers = this.findAll(':header');
    Content._dep.changed();
}

renderNav.js

Template.renderNav.contentData = function() {
    Content._dep.depend();
    // use Content.headers here
    ...
}