handle CoverageJSON Domain documents & expose .type

package.json

@@ -1,6 +1,6 @@
 {
   "name": "covjson-reader",
-  "version": "0.8.4",
+  "version": "0.9.0",
   "license": "BSD-3-Clause",
   "description": "A reader for CoverageJSON files.",
   "repository": {

src/Coverage.js

@@ -1,4 +1,6 @@
 import ndarray from 'ndarray'
+
+import {COVERAGE} from './constants.js'
 import {shallowcopy, minMax, assert, asTime,
   indexOfNearest, indicesOfNearest, PREFIX} from './util.js'
 import {isISODateAxis, isLongitudeAxis, getLongitudeWrapper} from './referencing.js'
@@ -28,6 +30,8 @@ export default class Coverage {
   constructor (covjson, options) {
     this._covjson = covjson
 
+    this.type = COVERAGE
+
     /**
      * JSON-LD document
      * 

src/CoverageCollection.js

@@ -1,3 +1,4 @@
+import {COVERAGECOLLECTION} from './constants.js'
 import {default as Coverage, transformDomain, transformParameter} from './Coverage.js'
 import {shallowcopy, asTime, PREFIX} from './util.js'
 import {isISODateAxis, isLongitudeAxis, getLongitudeWrapper} from './referencing.js'
@@ -13,6 +14,8 @@ export default class CoverageCollection {
    * @param {Object} covjson The CoverageJSON Collection document.
    */
   constructor(covjson) {
+    this.type = COVERAGECOLLECTION
+
     /**
      * JSON-LD document
      * 

src/constants.js

@@ -0,0 +1,4 @@
+export const DOMAIN = 'Domain'
+export const COVERAGE = 'Coverage'
+export const COVERAGECOLLECTION = COVERAGE + 'Collection'
+export const LINKRELPREFIX = 'http://www.iana.org/assignments/relation/'

src/reader.js

@@ -1,6 +1,8 @@
 import Coverage from './Coverage.js'
+import {transformDomain} from './Coverage.js'
 import CoverageCollection from './CoverageCollection.js'
 import {assert} from './util.js'
+import {COVERAGE, COVERAGECOLLECTION, DOMAIN, LINKRELPREFIX} from './constants.js'
 
 // NO FILE EXTENSION, to work around JSPM bug in handling package.json's "browser" field
 // see https://github.com/jspm/jspm-cli/issues/1062#issuecomment-170342414
@@ -27,31 +29,30 @@ export function load (url, options) {
 
 /**
  * Reads a CoverageJSON document and returns a {@link Promise} that succeeds with
- * a {@link Coverage} or {@link CoverageCollection} object.
+ * a Domain, {@link Coverage}, or {@link CoverageCollection} object.
  * 
  * Note that if the document references external domain or range documents,
  * then these are not loaded immediately. 
  * 
  * 
  * @example
  * CovJSON.read('http://example.com/coverage.covjson').then(function (cov) {
- *   // work with Coverage object
+ *   // work with Coverage data object
  * }).catch(function (e) {
- *   // there was an error when loading the coverage
+ *   // there was an error when loading the coverage data
  *   console.log(e)
  * })
  * @param {Object|string} input
- *    Either a URL pointing to a CoverageJSON Coverage or Coverage Collection document
- *    or a CoverageJSON Coverage or Coverage Collection object.
+ *    A CoverageJSON Domain, Coverage, or Coverage Collection document, as URL or object,
  * @param {Object} [options]
  *   An options object. 
  * @param {Object} [options.headers]
  *   Additional HTTP headers to send if input is a URL.
  * @param {Object} [options.eagerload]
  *   Request a stand-alone CoverageJSON document (with domain and ranges embedded) if input is a URL.
- *   Note that the server may ignore that preference.
+ *   Note that the server may ignore that preference. 
  * @return {Promise} 
- *    A promise object succeeding with a {@link Coverage} or {@link CoverageCollection} object,
+ *    A promise object succeeding with a Domain, {@link Coverage}, or {@link CoverageCollection} object,
  *    and failing with an {@link Error} object.
  */
 export function read (input, options = {}) {
@@ -71,18 +72,23 @@ export function read (input, options = {}) {
  */
 function transformCovJSON (obj, headers) {
   checkValidCovJSON(obj)
-  if (obj.type !== 'Coverage' && obj.type !== 'CoverageCollection') {
-    throw new Error('CoverageJSON document must be of Coverage or CoverageCollection type')
+  if ([COVERAGE, COVERAGECOLLECTION, DOMAIN].indexOf(obj.type) === -1) {
+    throw new Error('CoverageJSON document must be of Coverage, CoverageCollection, or Domain type')
   }
 
   let result
-  if (obj.type === 'Coverage') {
+  if (obj.type === DOMAIN) {
+    transformDomain(obj)
+    result = obj
+  } else  if (obj.type === COVERAGE) {
     result = new Coverage(obj)
   } else {
     result = new CoverageCollection(obj)
   }
 
-  addLinkRelations(result, headers)
+  if (obj.type === COVERAGE || obj.type === COVERAGECOLLECTION) {
+    addLinkRelations(result, headers)
+  }
 
   return result
 }
@@ -91,10 +97,7 @@ function transformCovJSON (obj, headers) {
  * Scans the supplied HTTP headers for Link relations and adds them
  * to the .ld property of the Coverage/CoverageCollection.
  */    
-function addLinkRelations (cov, headers) {
-  // for registered rel's
-  const IANAPrefix = 'http://www.iana.org/assignments/relation/'
-
+function addLinkRelations (cov, headers) {  
   if (!headers || !headers['link']) {
     return
   }
@@ -113,7 +116,7 @@ function addLinkRelations (cov, headers) {
       }
       let rel = param.substring(relStart+5, param.length-1)
       if (!rel.startsWith('http://') && !rel.startsWith('https://')) {
-        rel = IANAPrefix + rel
+        rel = LINKRELPREFIX + rel
       }
       if (ld[rel]) {
         if (Array.isArray(ld[rel])) {
@@ -139,11 +142,11 @@ function addLinkRelations (cov, headers) {
  */
 function checkValidCovJSON (obj) {
   assert('type' in obj, '"type" missing')
-  if (obj.type === 'Coverage') {
+  if (obj.type === COVERAGE) {
     assert('parameters' in obj, '"parameters" missing')
     assert('domain' in obj, '"domain" missing')
     assert('ranges' in obj, '"ranges" missing')
-  } else if (obj.type === 'CoverageCollection') {
+  } else if (obj.type === COVERAGECOLLECTION) {
     assert(Array.isArray(obj.coverages), '"coverages" must be an array')
   }
 }

test/Coverage.js

@@ -7,14 +7,23 @@ import 'core-js/es6/map'
 import assert from 'assert'
 
 import {read} from '../lib/reader.js'
+import {COVERAGE} from '../lib/constants.js'
 
 import {FIXTURES} from './data.js'
 
+describe('Coverage structure', () => {
+  it('should have loaded=true and type=Coverage', () => {
+    return read(FIXTURES.Profile()).then(cov => {
+      assert.equal(cov.loaded, true)
+      assert.equal(cov.type, COVERAGE)
+    })
+  })
+})
+
 describe('Coverage methods', () => {
   describe('#subsetByIndex', () => {
     it('should not modify the original coverage', () => {
       return read(FIXTURES.Profile()).then(cov => {
-        assert.equal(cov.loaded, true)
         return cov.subsetByIndex({z: 0}).then(subset => {
           return Promise.all([cov.loadDomain(), cov.loadRange('PSAL')]).then(([domain,range]) => {
             assert.strictEqual(domain.axes.size, 4)

test/CoverageCollection.js

@@ -7,10 +7,23 @@ import 'core-js/es6/map'
 import assert from 'assert'
 
 import {read} from '../lib/reader.js'
+import {COVERAGECOLLECTION} from '../lib/constants.js'
 
 import {runServerIfNode} from './node-setup.js'
 import {FIXTURES} from './data.js'
 
+describe('CoverageCollection structure', () => {
+
+  runServerIfNode()
+
+  it('should have correct structure', () => {
+    return read(FIXTURES.CollectionURL).then(coll => {
+      assert.equal(coll.type, COVERAGECOLLECTION)
+    })
+  })
+
+})
+
 describe('CoverageCollection methods', () => {
 
   runServerIfNode()

test/Domain.js

@@ -0,0 +1,20 @@
+// IE11 support
+import 'core-js/es6/array'
+import 'core-js/es6/promise'
+import 'core-js/es6/symbol'
+import 'core-js/es6/map'
+
+import assert from 'assert'
+
+import {read} from '../lib/reader.js'
+import {DOMAIN} from '../lib/constants.js'
+
+import {FIXTURES} from './data.js'
+
+describe('Domain structure', () => {
+  it('should have correct structure', () => {
+    return read(FIXTURES.GridRegularDomain()).then(domain => {
+      assert.equal(domain.type, DOMAIN)
+    })
+  })      
+})

test/data.js

@@ -166,6 +166,30 @@ export const FIXTURES = {
         }
       }
     }),
+    GridRegularDomain: () => ({
+      "type" : "Domain",
+      "profile" : "Grid",
+      "axes": {
+        "x": { "values": [-10,-5,0] },
+        "y": { "start": 40, "stop": 50, "num": 2 },
+        "z": { "values": [5] },
+        "t": { "values": ["2010-01-01T00:12:20Z"] }
+      },
+      "rangeAxisOrder": ["t","z","y","x"],
+      "referencing": [{
+        "components": ["y","x","z"],
+        "system": {
+          "type": "GeodeticCRS",
+          "id": "http://www.opengis.net/def/crs/EPSG/0/4979"
+        }
+      }, {
+        "components": ["t"],
+        "system": {
+          "type": "TemporalRS",
+          "calendar": "Gregorian"
+        }
+      }]
+    }),
     CollectionEmpty: () => ({
       "type" : "CoverageCollection",
       "coverages": []