How to implement not with if statement in Ember Handlebars?

Question

I have a statement like this:

{{#if IsValid}}

I want to know how I can use a negative if statement that would look like that:

Answer 1

You have many ways of doing that.

1. Use {{unless}}:

{{#unless isValid}}
  ...
{{else}}
  ...
{{/unless}}

2. Use inline-if helper:

{{#if (if isValid false true)}}
  ...
{{else}}
  ...
{{/if}}

3. Use ember-truth-helpers addon:

{{#if (not isValid)}}
  ...
{{else}}
  ...
{{/if}}