blue-button-generate

Blue Button CCDA Generator

blue-button-generate is a module to generate CCDA files from JSON data. Currently it only supports blue-button JSON data model.

Usage

var fs = require('fs');
var bb = require('blue-button');
var bbg = require('blue-button-generate');

var xmlString = fs.readFileSync('test/fixtures/files/ccda_xml/CCD_1.xml', 'utf-8');
var record = bb.parseString(xmlString);

// ...
// changes to record
// ...

// get back xml as text
var updatedXmlString = bbg.generateCCD(record);

Implementation

blue-button-generate uses javascript template objects for implementation. Each template in CCDA is represented with an object. As an example Reaction Observation object is shown

var reactionObservation = exports.reactionObservation = {
    key: "observation",
    attributes: {
        "classCode": "OBS",
        "moodCode": "EVN"
    },
    content: [
        fieldLevel.templateId("2.16.840.1.113883.10.20.22.4.9"),
        fieldLevel.id,
        fieldLevel.nullFlavor("code"),
        fieldLevel.text(leafLevel.sameReference("reaction")),
        fieldLevel.statusCodeCompleted,
        fieldLevel.effectiveTime, {
            key: "value",
            attributes: [
                leafLevel.typeCD,
                leafLevel.code
            ],
            dataKey: 'reaction',
            existsWhen: condition.codeOrDisplayname,
            required: true
        }, {
            key: "entryRelationship",
            attributes: {
                "typeCode": "SUBJ",
                "inversionInd": "true"
            },
            content: severityObservation,
            existsWhen: condition.keyExists('severity')
        }
    ]
};

This template is internally used with a call

js2xml.update(xmlDoc, input, context, reactionObservation);

where xmlDoc is the parent xml document (Allergy Intolerance Observation) and input is the immediate parent of bluebutton.js object that describes Reaction Observation. context is internally used for indices in text references.

Motivation

This approach is an alternative to direct programming or text based templates such as in bluebutton.js and is motivated by the following

• Each template directly follows the actual specification. One can easily match each node in the template to the actual statements in the specification.
• Individual templates can be tested independently without any additional flags or programming.
• Required elements are specified in the template and get nullFlavor automatically when no data exists.
• No coding required to add new templates.
• It is also a step in the right direction for the possible future directions
• Factoring out data model dependencies so that blue-button](https://github.com/amida-tech/blue-button) data model changes or other data models can be accomodated more easily
• Automatic generation of templates from blue-button like CCDA parsers.

Template Structure

The following are the properties of the templates

• key: This is the name for the xml element.
• attributes: This describes the attributes of the element. attributes can be an object of with key and value pairs for each attribute or it can be an array of such objects. Each attribute object or can be a function with input argument that returns attributes.
• text: This is a function with input attribute that returns text value of the element.
• content: This is an array of other templates that describe the children of the element. For a single child an object can be used.
• dataKey: This is the property of input that serves as the data for the template.
• required: This identifies if template is required or not. If template is required and there is not value in the input a nullFlavor node is created.
• dataTransform: This is a function to transform the input.
• existWhen: This is a boolean function with input argument to describe it the elements should exists or not.