Data mapper chain
Simple data mapper library meant to be run in browser to ease data transformation for IoT devices in JS.
Example: Simple in browser
<body>
...
<script src="https://cdn.jsdelivr.net/npm/@exploratoryengineering/data-mapper-chain@0.6"></script>
<script>
var myMapper = dmc.create()
.chunk({ start: 2, size: 2})
.hexToInt();
console.log(myMapper.mapData("babe")); // Prints 190
</script>
</body>Example: In ts
You must first install the dependency
npm i @exploratoryengineering/data-mapper-chainUsing shorthand
import { DataMapperChain } from "@exploratoryengineering/data-mapper-chain";
// Create a chain and add mappers
const dataMapperChain = new DataMapperChain()
.chunk({
start: 50,
size: 4,
})
.hexToInt();
// Raw data from device
const deviceData: string = `47eee3803e3a8c713f8daf7242fc6666423c28c04111d84000024b00a3030c261b010b91d3`;
// Run mapper
dataMapperChain.mapData(deviceData); // prints 587Instanciating mappers directly
import { DataMapperChain, Mappers } from "@exploratoryengineering/data-mapper-chain";
/**
* We know that on byte 25 there is 2 bytes of data which is a hex encoded uint16
* We solve this by doing the following:
*/
/**
* Create a Chunk mapper
*/
const chunk = Mappers.chunk({
start: 50,
size: 4,
});
/**
* Create a HexToInt mapper
*/
const hexToInt = Mappers.hexToInt();
// Create a DataMapperChain
const dataMapperChain = new DataMapperChain();
// Add mappers
dataMapperChain.addMapper(chunk);
dataMapperChain.addMapper(hexToInt);
// Raw data from device
const deviceData: string = `47eee3803e3a8c713f8daf7242fc6666423c28c04111d84000024b00a3030c261b010b91d3`;
// Run mapper
dataMapperChain.mapData(deviceData); // prints 587
What
The main workhorse is the DataMapperChain which serves a couple of purposes. It contains the different mappers you want to use in your "chain" of mappers and has functions to apply all mappers on a data set. It also allows for serializing configuration of both the chain and the added mappers. This serialized version can again be loaded directly into a new DataMapperChain which is now fully configured with the saved params.
Why
I found myself fiddling with a lot of IoT data recently and a need to graph it easily. The libs which which I found either relied heavily on eval or didn't have any typings. I put together this lib which is modular and pluggable and hopefully solves someones problem alongside mine.
Pluggable
While the lib provide a decent amount of mappers as a starting point, I know I don't cover every use case out there.
Tiny
The library relies mostly on native functions meaning it shouldn't get too big. More complex mappers should be application specific and be a part of the application which imports the library.