Can I Use Logical Operators Like 'OR' in Handlebars.js {{#if}} Conditionals?

Using Logical Operators in Handlebars.js {{#if}} Conditionals

Handlebars.js provides a powerful {{#if}} conditional operator to conditionally render content based on a given expression. However, the standard operator only supports simple truthy/falsy conditions. This limits its ability to express more complex logical relationships.

Problem:

Is it possible to incorporate logical operators, such as OR (||), into the handlebars.js {{#if}} conditional operator?

Answer:

While handlebars.js does not natively support logical operators in its conditional operator, it is possible to achieve this functionality by utilizing a block helper. Block helpers are custom functions that can be registered with handlebars to extend its functionality.

Here's how you can register a block helper named 'ifCond' to handle logical conditions:

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

This helper checks if two values, v1 and v2, are equal. If they are, it returns the contents of the 'true' block (options.fn). Otherwise, it returns the contents of the 'false' block (options.inverse).

To use this helper in your template, simply call it with the values you want to compare:

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

This will output one of the two blocks based on whether v1 and v2 are equal or not.

While using block helpers to achieve this functionality may not align with the philosophy of Handlebars, it provides a way to extend its capabilities and handle complex logical relationships in your templates.

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