Merge pull request #32 from HL7/choice_types

Choice types

.gitignore

@@ -6,4 +6,3 @@ build
 .DS_Store
 .editorconfig
 Makefile
-browser-build/fhirpath.min.js.map

CHANGELOG.md

@@ -3,6 +3,16 @@
 This log documents significant changes for each release.  This project follows
 [Semantic Versioning](http://semver.org/).
 
+## [1.0.0] - 2019-12-19
+### Added
+- Support for FHIR "choice types" (e.g. Observation.value).  The support is
+  currently limited to being able to specify paths like Observation.value (when
+  the resource might actually contain Observation.valueString).
+### Changed
+- Remove the deprecated "context" parameter from the "compile" function.  The
+  context should be passed into the function that "compile" returns.  This
+  breaking change is the reason for the major version number increment.
+
 ## [0.17.5] - 2019-11-18
 ### Fixed
 - Although one could add a Quantity to a date, subtracting the quantity resulted

README.md

@@ -19,6 +19,8 @@ npm install –save fhirpath
 
 ```js
 const fhirpath = require('fhirpath');
+// For FHIR model data (choice type support) pull in the model file:
+const fhirpath_r4_model = require('fhirpath/fhir-context/r4');
 ```
 
 ### Web-browser:
@@ -30,6 +32,14 @@ then use as shown below.  Note that this file is UTF-8 encoded, and the script
 needs to be loaded as such.  For an example, see the
 browser-build/test/protractor/index.html file, which sets the page to be UTF-8.
 
+For FHIR-specific features (e.g. handling of choice type fields), you will also
+want to include a second file with the desired FHIR version model data, e.g.
+fhirpath.r4.min.js for pulling in the R4 model.  (At the moment, those files are
+small, but it would not be surprising if they grew as more support for FHIR type
+handling is added, so they are kept seperate from the main FHIRPath file.)
+These will define additional global variables like "fhirpath_r4_model" or
+"fhirpath_stu3_model".
+
 ## Usage
 ```
 // Evaluating FHIRPath
@@ -41,10 +51,14 @@ fhirpath.evaluate({"resourceType": "Patient", ...}, 'Patient.name.given');
 // name/value pairs:
 fhirpath.evaluate({}, '%a - 1', {a: 5});
 
+// To include FHIR model data (for support of choice types), pass in the model
+// data object as the fourth argument:
+fhirpath.evaluate({"resourceType": "Observation", "valueString": "green"},
+                  'Observation.value', null, fhirpath_r4_model);
+
 // Precompiling fhirpath - result can be reused against multiple resources
 const path = fhirpath.compile('Patient.name.given');
 var res2 = path({"resourceType": "Patient", ...}, {a: 5, ...});
-
 ```
 
 
@@ -87,6 +101,13 @@ fhirpath --expression '%v + 2' --resourceJSON '{}' --variables '{"v": 5}'
 > ]
 ```
 
+FHIR model data can be included via --model and the FHIR release version (in
+lower case, e.g., 'stu3' or 'r4').
+
+```sh
+fhirpath --expression 'Observation.value' --resourceJSON '{"resourceType": "Observation", "valueString": "Green"}' --model r4
+```
+
 If given just the FHIRPath expression, the utility will print the parsed tree:
 
 ```sh
@@ -121,7 +142,8 @@ Completed sections:
 - 8   (Environment Variables)
 
 We are deferring handling information about FHIR resources, as much as
-possible.  This affects implementation of the following sections:
+possible, with the exception of support for choice types.  This affects
+implementation of the following sections:
 - 6.3 (Types) - deferred
 Also, because in JSON DateTime and Time types are represented as strings, if a
 string in a resource looks like a DateTime or Time (matches the regular

bin/fhirpath

@@ -9,6 +9,7 @@ options.option('-e, --expression <expr>', 'FHIRPath expression');
 options.option('-f, --resourceFile <path name>', 'A file containing the JSON resource.');
 options.option('-r, --resourceJSON <JSON>', 'JSON resource.');
 options.option('-v, --variables <JSON>', 'JSON hash of variables.');
+options.option('-m, --model <stu3 | r4>', 'Include FHIR model data.');
 options.parse(process.argv);
 
 // this cli util is part of public interface of fhirpath
@@ -36,7 +37,14 @@ else {
     if (context)
       context = JSON.parse(context);
     let resource = JSON.parse(resourceJSON);
-    let res = fp.evaluate(resource, expr, context);
+    let model;
+    if (options.model) {
+      let supportedVersions = ['stu3', 'r4'];
+      if (supportedVersions.indexOf(options.model) < 0)
+        throw new Error('FHIR model must be one of '+supportedVersions);
+      model = require('../fhir-context/'+options.model);
+    }
+    let res = fp.evaluate(resource, expr, context, model);
     console.log('fhirpath(' + expr + ') =>');
     console.log(JSON.stringify(res, null, " "));
   }

browser-build/.gitignore

@@ -1,2 +1,2 @@
-fhirpath.min.js
+*.min.js*
 fhirpath.zip

browser-build/test/protractor/index.html

@@ -8,17 +8,30 @@
 <textarea id="expression" onkeyup="evaluateFP()"></textarea>
 <textarea id="resource" onkeyup="evaluateFP()"></textarea>
 <textarea id="result"></textarea>
+<br>
+FHIR model:
+<input id="r4" name="model" type="radio" value="r4" onclick="evaluateFP()"> R4
+<input id="stu3" name="model" type="radio" value="stu3" onclick="evaluateFP()"> STU3
 <script src="../../fhirpath.min.js"></script>
+<script src="../../fhirpath.r4.min.js"></script>
+<script src="../../fhirpath.stu3.min.js"></script>
 <script>
 function evaluateFP() {
   var expr = document.getElementById('expression').value;
   var resource = document.getElementById('resource').value;
-  console.log("expr="+expr);
-  console.log(resource);
+  var modelChoices = document.getElementsByName('model');
+  var model;
+  for (let modelChoice of modelChoices) {
+    if (modelChoice.checked) {
+      model = modelChoices.value === 'r4' ? fhirpath_r4_model :
+        fhirpath_stu3_model;
+      break;
+    }
+  }
   if (expr && resource) {
     resource = JSON.parse(resource);
     document.getElementById('result').value =
-      JSON.stringify(fhirpath.evaluate(resource, expr));
+      JSON.stringify(fhirpath.evaluate(resource, expr, null, model));
   }
 }
 </script>

browser-build/test/protractor/spec/browser.spec.js

@@ -9,4 +9,18 @@ describe('Browser build of FHIRPath', function() {
     resource.sendKeys('{}');
     expect(result.getAttribute('value')).toBe('[3]');
   });
+
+  it('should have working model files', function() {
+    browser.get(demoURL);
+    let expression = $('#expression');
+    let resource = $('#resource');
+    resource.sendKeys('{"resourceType": "Observation", "valueString": "green"}');
+    expression.sendKeys('Observation.value');
+    let result = $('#result');
+    expect(result.getAttribute('value')).toBe('[]'); // no model yet
+    for (let fhirVers of ['stu3', 'r4']) {
+      $('#'+fhirVers).click(); // changes the model used
+      expect(result.getAttribute('value')).toBe('["green"]');
+    }
+  });
 });

browser-build/webpack.config.js

@@ -1,34 +1,55 @@
 const CopyPlugin = require('copy-webpack-plugin');
 
-module.exports = {
-  node: {
-    fs: "empty"
-  },
-  entry: './fhirpathRequire.js',
-  mode: 'production',
-  // mode: 'development',
-  devtool: 'source-map',
-  output: {
-    path: __dirname,
-    filename: './fhirpath.min.js',
-  },
-  module: {
-    rules: [
-      {
-        test: /\.m?js$/,
-        exclude: /(node_modules|bower_components)/,
-        use: {
-          loader: 'babel-loader',
-          options: {
-            presets: ['@babel/preset-env']
+/**
+ *  Returns a base webpack configuration object with settings used by more than
+ *  one output file.
+ */
+function makeBaseConfig() {
+  return {
+    node: {
+      fs: "empty"
+    },
+    mode: 'production',
+    devtool: 'source-map',
+    output: {
+      path: __dirname
+    },
+    module: {
+      rules: [
+        {
+          test: /\.m?js$/,
+          exclude: /(node_modules|bower_components)/,
+          use: {
+            loader: 'babel-loader',
+            options: {
+              presets: ['@babel/preset-env']
+            }
           }
         }
-      }
-    ]
-  },
-  plugins: [
-    new CopyPlugin([
-      { from: '../LICENSE.md', to: '.' }
-    ]),
-  ],
-};
+      ]
+    }
+  };
+}
+
+module.exports = [];
+
+// Main FHIRPath file
+let config = makeBaseConfig();
+config.entry = '../src/fhirpath';
+config.output.filename = './fhirpath.min.js';
+config.output.library = 'fhirpath'; // global variable for the library
+config.plugins = [
+  new CopyPlugin([
+    { from: '../LICENSE.md', to: '.' }
+  ]),
+];
+module.exports.push(config);
+
+// FHIR model files
+for (let fhirVers of ['stu3', 'r4']) {
+  config = makeBaseConfig();
+  config.entry = '../fhir-context/'+fhirVers+'/index';
+  config.output.filename = './fhirpath.'+fhirVers+'.min.js';
+  config.output.library = 'fhirpath_'+fhirVers+'_model';
+  module.exports.push(config);
+}