Conditionally mark a checkbox as checked in Meteor using Blaze

问题

I'm not entirely sure what's wrong here, or how I'm supposed to approach it differently - but googling just brings up references to 'isChecked' - something I'm not using.

I just want to flag a checkbox as checked if the associated field value is present:

<input type="checkbox" name="services.bananaExports" {{ #if currentUser.profile.services.bananaExports }} checked {{ /if }} />

But I'm getting:

Reactive HTML attributes must either have a constant name or consist of a single {{helper}} providing a dictionary of names and values. A template tag of type BLOCKOPEN is not allowed here.

Honestly I'm not sure what that's trying to tell me, I'm new to meteor/blaze but it's a pretty basic if clause? Can I not issue an if statement here? If not how would I approach this?

回答1:

The best solution I can think of is to define a helper like this one:

Template.registerHelper('isTruthy', function(varName) {
  return !!varName;
});

Then you can do things like this:

{{#each foodList}}
  {{foodName}} <input type="checkbox" checked={{isTruthy eaten}}>
{{/each}}

Of course, in your case:

<input type="checkbox" name="services.bananaExports" checked={{isTruthy currentUser.profile.services.bananaExports}}>

来源：https://stackoverflow.com/questions/32055096/conditionally-mark-a-checkbox-as-checked-in-meteor-using-blaze