openmct/platform/containment/src/CapabilityTable.js

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 * Administration. All rights reserved.
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define(
    [],
    function () {

        /**
         * Build a table indicating which types are expected to expose
         * which capabilities. This supports composition policy (rules
         * for which objects can contain which other objects) which
         * sometimes is determined based on the presence of capabilities.
         * @constructor
         * @memberof platform/containment
         */
        function CapabilityTable(typeService, capabilityService) {
            var self = this;

            // Build an initial model for a type
            function buildModel(type) {
                var model = Object.create(type.getInitialModel() || {});
                model.type = type.getKey();
                return model;
            }

            // Get capabilities expected for this type
            function getCapabilities(type) {
                return capabilityService.getCapabilities(buildModel(type));
            }

            // Populate the lookup table for this type's capabilities
            function addToTable(type) {
                var typeKey = type.getKey();
                Object.keys(getCapabilities(type)).forEach(function (key) {
                    self.table[key] = self.table[key] || {};
                    self.table[key][typeKey] = true;
                });
            }

            // Build the table
            this.table = {};
            (typeService.listTypes() || []).forEach(addToTable);
        }

        /**
         * Check if a type is expected to expose a specific capability.
         * @param {string} typeKey the type identifier
         * @param {string} capabilityKey the capability identifier
         * @returns {boolean} true if expected to be exposed
         */
        CapabilityTable.prototype.hasCapability = function (typeKey, capabilityKey) {
            return (this.table[capabilityKey] || {})[typeKey];
        };

        return CapabilityTable;
    }
);