Introduction
When you are configuring for integration, there may be a need to create an array with configurable start and end limits.
For example, you want to create an array with the objects has id property starting from 4 to 7 through its objects, as below:
```
[
{
"id": 4
},
{
"id": 5
},
{
"id": 6
},
{
"id": 7
}
]
```
In this guide, we will show you how to do it within an entity transformer configuration.
Steps
-
First, you must include or set the limits (start and end) in the entity data. Example:
{ "start": 4, "end": 7 } -
Chain multiple entity transformers is recommended because you will have more than one entity transformer if you create it in a single entity transformer.
-
Then, inside a Data, transform data using mappers and conditions, you need to subtract the end limit from the start limit using a value setter and an operator mapper (subtraction) to get the difference. To create an array from 4 to 7, add the Prepared Operator mapper (Addition) and set the Left to 1 (number).
- Next, after getting the difference, it should be converted to an array where the length equals to the difference using List: Fill the list with a value mapper and set the Length to &@, which represents the difference property’s current value. When the difference is 4, the result is an array of integers, i.e., [“4”, “4”, “4”, “4”].
-
Then, the array should be converted to an array of objects using the Move data between accessors. The Source accessor is a Key accessor, and the Destination accessor is the Structure accessor. So, the array would be something like this:
{ "difference": [ { "index": "0", "value": 3 }, { "index": "1", "value": 3 }, { "index": "2", "value": 3 } ] }
-
Then, we can copy the start limit to all the objects using the Recursively copy values to children transformer so that every object will have the start limit, such as below.
{ "difference": [ { "index": "0", "value": 3, "start": 4 }, { "index": "1", "value": 3, "start": 4 }, { "index": "2", "value": 3, "start": 4 } ] }
- Then, inside a Node, transform nodes, you need to create a new attribute, for example, id, where the value is the sum of the index and start values.
- Then you can remove other attributes, except id, using the Key Filter.
- Finally, in the data transformer (outside the node) use the List Mapper and the Get values mapper to tidy up the data structure.
And here is the final result.
```
{
"start": 4,
"end": 7,
"difference": [
{
"id": 4
},
{
"id": 5
},
{
"id": 6
},
{
"id": 7
}
]
}
```