[Telemetry] Add metadata and formatter support

Add TelemetryMetadataManager which assists developers in interrogating
telemetry metadata to find values that are useful for them.

Add TelemetryValueFormatter to simplify the parsing (retrieval of numerical
values) and formatting (retrieval of displayable string value) of datums.

https://github.com/nasa/openmct/issues/1310

src/api/telemetry/TelemetryMetadataManager.js

@@ -0,0 +1,142 @@
+/*****************************************************************************
+ * Open MCT, Copyright (c) 2014-2016, United States Government
+ * as represented by the Administrator of the National Aeronautics and Space
+ * Administration. All rights reserved.
+ *
+ * Open MCT is licensed under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * Open MCT includes source code licensed under additional open source
+ * licenses. See the Open Source Licenses file (LICENSES.md) included with
+ * this source code distribution or the Licensing information page available
+ * at runtime from the About dialog for additional information.
+ *****************************************************************************/
+
+
+define([
+    'lodash'
+], function (
+    _
+) {
+
+    function valueMetadatasFromOldFormat(metadata) {
+        var valueMetadatas = [];
+
+        metadata.domains.forEach(function (domain, index) {
+            var valueMetadata = _.clone(domain);
+            valueMetadata.hints = {
+                x: index,
+                domain: index
+            };
+            valueMetadatas.push(valueMetadata);
+        });
+
+        metadata.ranges.forEach(function (range, index) {
+            var valueMetadata = _.clone(range);
+            valueMetadata.hints = {
+                y: index,
+                range: index,
+                priority: index + metadata.domains.length
+            };
+
+            if (valueMetadata.type === 'enum') {
+                valueMetadata.key = 'enum';
+                valueMetadata.hints.y -= 10;
+                valueMetadata.hints.range -= 10;
+                valueMetadata.enumerations =
+                    _.sortBy(valueMetadata.enumerations.map(function (e) {
+                        return {
+                            string: e.string,
+                            value: +e.value
+                        };
+                    }), 'e.value');
+                valueMetadata.values = _.pluck(valueMetadata.enumerations, 'value');
+                valueMetadata.max = _.max(valueMetadata.values);
+                valueMetadata.min = _.min(valueMetadata.values);
+            };
+
+            valueMetadatas.push(valueMetadata);
+        });
+
+        return valueMetadatas;
+    }
+
+    function applyReasonableDefaults(valueMetadata, index) {
+        valueMetadata.source = valueMetadata.source || valueMetadata.key;
+        valueMetadata.hints = valueMetadata.hints || {};
+
+        if (!valueMetadata.hints.hasOwnProperty('priority')) {
+            valueMetadata.hints.priority = index;
+        }
+        return valueMetadata;
+    }
+
+    /**
+     * Utility class for handling telemetry metadata for a domain object.
+     * Wraps old format metadata to new format metadata.
+     * Provides methods for interrogating telemetry metadata.
+     */
+    function TelemetryMetadataManager(domainObject) {
+        this.metadata = domainObject.telemetry || {};
+
+        if (this.metadata.values) {
+            this.valueMetadatas = this.metadata.values;
+        } else {
+            this.valueMetadatas = valueMetadatasFromOldFormat(this.metadata);
+        }
+
+        this.valueMetadatas = this.valueMetadatas.map(applyReasonableDefaults);
+    }
+
+
+    /**
+     * Get value metadata for a single key.
+     */
+    TelemetryMetadataManager.prototype.value = function (key) {
+        return this.valueMetadatas.filter(function (metadata) {
+            return metadata.key === key
+        })[0];
+    };
+
+    /**
+     * Returns all value metadatas, sorted by priority.
+     */
+    TelemetryMetadataManager.prototype.values = function () {
+        return this.valuesForHints(['priority']);
+    };
+
+    /**
+     * Get an array of valueMetadatas that posess all hints requested.
+     * Array is sorted based on hint priority.
+     *
+     */
+    TelemetryMetadataManager.prototype.valuesForHints = function (
+        hints
+    ) {
+        function hasHint(hint) {
+            return this.hints.hasOwnProperty(hint);
+        }
+        function hasHints(metadata) {
+            return hints.every(hasHint, metadata);
+        }
+        var matchingMetadata = this.valueMetadatas.filter(hasHints);
+        var sortedMetadata = _.sortBy(matchingMetadata, function (metadata) {
+            return hints.map(function (hint) {
+                return metadata.hints[hint];
+            });
+        });
+        return sortedMetadata;
+    };
+
+
+    return TelemetryMetadataManager;
+
+});