How to Implement Logical Operators in Handlebars.js Conditionals?

Using Logical Operators Within Handlebars.js If Conditionals

In the familiar realm of handlebars.js, conditional rendering via the {{#if}} block introduces a common programming conundrum: how to implement logical operators within this framework? One might instinctively attempt to directly include such operators within the conditional, as seen in the example provided.

However, handlebars.js does not natively support logical operators within its conditionals. This sparks a dilemma: should one embark on the arduous task of crafting a custom helper or delve into existing solutions? To answer this question, let us explore a 'cheat' method utilizing block helpers.

The Block Helper Technique

This approach may challenge the purist principles of Handlebars, but it effectively bypasses its limitations. By registering a custom block helper, one can implement the desired logical operations. Consider the following example helper:

Handlebars.registerHelper('ifCond', function(v1, v2, options) {
  if(v1 === v2) {
    return options.fn(this);
  }
  return options.inverse(this);
});

Within your template, you can then employ this helper as follows:

{{#ifCond v1 v2}}
    {{v1}} is equal to {{v2}}
{{else}}
    {{v1}} is not equal to {{v2}}
{{/ifCond}}

This method essentially enables the use of the equality operator within Handlebars conditionals. While not adhering strictly to its design philosophy, it provides a practical workaround for incorporating logical operations. It is important to note that this approach may not be suitable for all scenarios, but it offers a feasible solution for specific use cases.

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