Meteor template and template helper

Question

This something what I can't understand and can't solve it...

Short example.

Template helper:

Template.bookDetails.helpers({

  book: function() {        

    console.log("Current router :_id: " + Router.current().params._id);
    return Books.findOne(Router.current().params._id);

}

Some lines of template:

<template name="bookDetails">
   ...
   {{#with book}}
     Title: {{book.title}} <br>
     Author: {{book.author}} <br>
     ISBN: {{book.isbn}} <br>
     ...more...
   {{/with}}
   ...
</template>

And the question is: why do I see print console.log() as many times as call book.some_field in template?

Is it normal???

You should only be seeing the log once unless there is something else in your code that is changing your data context for that helper function. I.e. is your Router.current().params._id changing at all? Also... if you prefer, you can use {{title}} instead of {{book.title}} — Scalahansolo

saimeunt saimeunt · Accepted Answer · 2014-11-10T15:55:18

Yes this is normal because your code actually calls the book helper multiple times.

You have to replace your code with the following one to make things simpler :

{{#with book}}
  Title: {{title}} <br>
  Author: {{author}} <br>
  ISBN: {{isbn}} <br>
{{/with}}

The #with structure will set the current data context to the value returned by the helper and you can then access each property without referencing book.

Meteor template and template helper

1 Answers