Get Number Of Items Returned By The Previous Node

Ever found yourself staring at a workflow in n8n, scratching your head, wondering how many items the previous node actually returned? You’re not alone. I’ve been there, and trust me, it’s a game-changer when you can easily get the number of items returned by the previous node. Whether you’re using JavaScript or Python, I’ve got you covered with some slick code snippets that’ll make your life a whole lot easier. So, buckle up, and let’s dive into the world of n8n and learn how to count items from previous node like a pro.

Why You Need to Count Items from Previous Node

Before we get into the nitty-gritty, let’s talk about why this matters. In n8n, understanding how many items are coming out of a node can be crucial for your workflow. It’s like knowing the score in a game – you need to keep track to make smart moves. Whether you’re processing data, sending emails, or automating tasks, knowing the item count can help you optimize your workflow and avoid those pesky errors that keep you up at night.

JavaScript: The Easy Way to Count Items

Let’s start with JavaScript, the go-to language for many n8n users. Here’s how you can check the number of items returned by the previous node:

• First, we’ll check if the first item’s JSON object is empty.
• If it’s empty, we’ll return a result of 0.
• If it’s not empty, we’ll return the total number of items.

Here’s the code to make it happen:

const items = $input.all();
const firstItem = items[0];

if (!firstItem || Object.keys(firstItem.json).length === 0) {
    return [{ json: { results: 0 } }];
} else {
    return [{ json: { results: items.length } }];
}

Simple, right? This code snippet will give you the number of items returned by the previous node in a snap. And if you’re wondering about the output, it’s an array with a single object containing a “results” key. For example, if you had 8 items, your output would look like this:

[{ json: { results: 8 } }]

Python: Another Way to Count Items

Now, if you’re more of a Python person, don’t worry – I’ve got you covered too. The logic is similar, but here’s how you can do it in Python:

• We’ll check if the length of the first item’s JSON object is zero.
• If it’s zero, we’ll return a result of 0.
• If it’s not zero, we’ll return the total number of items.

Here’s the Python code to get the job done:

items = $input.all()
first_item = items[0] if items else None

if first_item is None or len(first_item['json']) == 0:
    return [{'json': {'results': 0}}]
else:
    return [{'json': {'results': len(items)}}]

Just like with JavaScript, this code will give you the number of items returned by the previous node in a clean and efficient way. And yes, the output format is the same – an array with a single object containing a “results” key.

Handling Empty JSON Objects

One thing you might be wondering about is what happens if the JSON object is empty. Both the JavaScript and Python code snippets handle this scenario gracefully. If the JSON object is empty, they return a result of 0. This is crucial because it prevents your workflow from breaking or giving you incorrect data.

So, if you’re dealing with data that might sometimes be empty, these code snippets have got your back. They ensure that your workflow keeps running smoothly, no matter what.

The Power of Knowing Your Item Count

Now that you know how to count items from previous node, let’s talk about why this is such a game-changer. When you’re working with n8n, every piece of data matters. Knowing how many items you’re dealing with can help you:

• Optimize your workflow for better performance.
• Avoid errors that come from unexpected data.
• Make smarter decisions based on the data you’re processing.

It’s like having a secret weapon in your automation arsenal. And the best part? It’s super easy to implement with the code snippets I’ve shared.

Ready to Take Your n8n Game to the Next Level?

So, there you have it – a simple, effective way to get the number of items returned by the previous node in n8n using JavaScript or Python. Whether you’re a seasoned pro or just starting out, these code snippets will save you time and headaches. And if you’re hungry for more n8n tips and tricks, be sure to check out our other resources. We’ve got everything you need to boost your workflow and take your automation game to the next level. Happy automating!