@resaleai/receipt-ast v1.2.0

receipt-components

This package is for building complex and evolving receipts using a simple XML style language and component engine. The XML is converted to a simple JS representation that is then converted to either HTML or an ESC/POS byte array at runtime with supplied data.

Getting started

First, install the package with yarn or npm:

npm install @resaleai/receipt-components

After that, import the ReceiptComponent class and create a new component with a template:

import { ReceiptComponent } from '@resaleai/receipt-components';

let Receipt = new ReceiptComponent({
  template: `<receipt>
    <text bold>Hello world!</text>
  </receipt>`,
});

Dependancies

This project tries not to use any deps, but the image processing does require access to a Canvas API. This is always available in the browser, and can be simulated using another package, such as...

After building the template, you can render the component into either HTML or the ESC/POS bytes using

let htmlStr = Receipt.renderHTML(); // build the HTML
let epBytes = Receipt.renderPrinterBytes(); // build the byte array

This will output

printer bytes and html

Templated

On top of this, there is a simple templating engine built in for putting dynamic data in the receipts.

example

Components

The component system is simple, but surprisingly powerful. Take, for instance, some sort of legalise that needs to be put on the bottom of every receipt:

let ReceiptLegalise = new ReceiptComponent({
  template: `<receipt>
    <align mode="center">
      <text scale="7:0">-------</text>
      <break lines="3" />
      <text font="2" multiLine>{{ tnLegal }}</text>
      <break lines="3" />
      <text scale="7:0">-------</text>
    </align>
  </receipt>`,
});

This component, as well as any other components we need, can be used in the template of any other receipt component by registering it in the components constructor param.

let Receipt = new ReceiptComponent({
  template:
  `<receipt>
    ...
    <ReceiptLegalise />
  </receipt>`
  components: {
    ReceiptLegalise
  }
})

let output = Receipt.renderPrinterBytes({
  tnLegal: "This is the legal statement, you are legally obligated to have a good time :)"
})

Note that the data is global. You must define any data you need in the render function.

TODO

allow passing options to a different renderer build html renderer move images in to a separate package write docs