> ## Documentation Index
> Fetch the complete documentation index at: https://calcs.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Linking Data Between Templates (Load Linking)

> How to implement load linking functionality to import data from one calculation to another

This guide explains how to add the link function in a template, allowing you to import data from another calculation. A common example is the load link feature which allows exporting the reactions of a beam to be used as input for column calculations.

## The Basics

<Frame>
  <img src="https://t6927027.p.clickup-attachments.com/t6927027/28aeeb8b-3007-45cb-80f1-2ffec9b2943a/image.png" alt="Beam calculator with link button" />
</Frame>

**Figure 1 - Beam calculator with the "link" button**

### Step 1: Create Export Data

First, create a equation widget in the template you want to obtain the data from. This equation widget should be a table (using double square brackets `[[]]`) containing all data you want to export.

<Frame>
  <img src="https://t6927027.p.clickup-attachments.com/t6927027/93f54f57-3f93-4fda-b970-2cbfe9b95d48/image.png" alt="Preparing data for exporting" />
</Frame>

**Figure 2 - Preparing the data for exporting**

Make sure to check the **"Export"** box for this widget:

<Frame>
  <img src="https://t6927027.p.clickup-attachments.com/t6927027/8320a9d9-6b06-4285-9c79-fb943910d124/image.png" alt="Export checkbox" />
</Frame>

### Step 2: Create Import Table

Create a table in the destination template where you need the imported data. This table should have the same number of columns as the exported table.

<Warning>
  Remember to add `"inputType": "string"` for text columns.
</Warning>

### Step 3: Add Link Function

In the import table, include the following code to create the link function:

```json theme={null}
{
    "type": "linkRow",
    "mappings": [
        {
            "sourceColumn": 0,
            "targetColumn": 0,
            "prependSheetName": true
        },
        {
            "sourceColumn": 1,
            "targetColumn": 1
        },
        {
            "sourceColumn": 2,
            "targetColumn": 2
        },
        {
            "sourceColumn": 3,
            "targetColumn": 3
        },
        {
            "sourceColumn": 4,
            "targetColumn": 4
        }
    ],
    "description": "Link to MAFI Bracket Calculator",
    "referenceId": "testinglink",  // ReferenceID from exported sheet 
    "linkRequired": true, // Required link for calc to be valid?
    "sourceDataColumns": [
        {
            "label": "Label",
            "sorted": true
        }
    ]
}
```

## Configuration Parameters

* **`referenceId`**: Must match the reference ID of the exported table
* **`sourceColumn`** and **`targetColumn`**: Refer to the column indices of the exported and imported tables respectively (the imported table can have a different column arrangement)
* **`prependSheetName`**: Set to `true` to include the sheet name in the imported data
* **`linkRequired`**: Set to `true` if the link is required for the calculation to be valid

### Final Configuration

Make sure to check both "Expand" and "Show in Summary" boxes for the linking widget.

<Tip>
  A [tutorial video](https://drive.google.com/file/d/1c3jPkhNQSrnJWeYtHMu-GWbRIeUbTwsg/view) is available, created by Brooks while teaching Qiming.
</Tip>

## Advanced Linking

For more advanced linking concepts, including backend architecture and common pitfalls, refer to this comprehensive learning session:

[Advanced Load Linking Session](https://drive.google.com/file/d/1I0imRkK91oU96elaBzjVOr79XAieMuqR/view?usp=sharing)

This recording covers:

* How load linking works on the backend
* How to design new types of links (not necessarily just loads)
* Common pitfalls and how to avoid them
* Best practices for complex linking scenarios