Handlebars Js How To Access Parent Index In Nested Each

Handlebars.js is a powerful templating engine that allows developers to build dynamic web pages with ease. One common task when working with nested arrays or objects in Handlebars is accessing the parent index within a nested `each` block. This can come in handy when you need to reference the position of the parent element within the loop. In this guide, we will show you how to accomplish this effectively.

To access the parent index in a nested `each` block in Handlebars, you can leverage the `@key` keyword along with the lookup helper to retrieve the index of the outer loop. Let's walk through an example to illustrate this concept.

Suppose you have an array of objects called `parentArray`, and each object contains a property called `children` which is also an array. In your Handlebars template, you want to loop through both the parent array and its children array while accessing the index of the parent element. Here's how you can achieve this:

{{#each parentArray}}
  Parent Index: {{@index}}
  {{#each children}}
    Parent Index (Accessed): {{lookup ../ '@index'}}
    Child Index: {{@index}}
    Child Name: {{name}}
  {{/each}}
{{/each}}

In the above code snippet, we first iterate over `parentArray` using the `each` block. Within this block, we output the parent index using `@index`. Then, we nest another `each` block to iterate over the `children` array. To access the parent index within the nested block, we use the `lookup` helper passing in `../` to navigate up one level and then '@index' to retrieve the index of the parent array.

By using the `@index` and `lookup` together, you can effectively access the parent index within nested `each` blocks in Handlebars.js. This technique provides a simple and efficient way to work with hierarchical data structures and maintain the context of the parent element during iteration.

Remember that Handlebars provides a clean and intuitive syntax for creating dynamic templates, making it easier for developers to handle complex data structures in their applications. Experiment with different scenarios and tailor this approach to suit your specific requirements.

In conclusion, mastering the ability to access parent indices in nested `each` blocks can significantly enhance your templating capabilities in Handlebars.js. With the right tools and knowledge, you can streamline your template logic and build dynamic web pages efficiently. Happy coding!