@themost/data/data-listeners.js

MOST Web Framework Codename Blueshift - Data module

// MOST Web Framework 2.0 Codename Blueshift BSD-3-Clause license Copyright (c) 2017-2022, THEMOST LP All rights reserved
var async = require('async');
var {sprintf} = require('sprintf-js');
var _ = require('lodash');
var {isEqual} = require('lodash');
var {QueryUtils} = require('@themost/query');
var {QueryField} = require('@themost/query');
var {QueryFieldRef} = require('@themost/query');
var {NotNullError, DataError} = require('@themost/common');
var {UniqueConstraintError} = require('@themost/common');
var {TraceUtils} = require('@themost/common');
var {TextUtils} = require('@themost/common');
var {DataCacheStrategy} = require('./data-cache');
var {DataFieldQueryResolver} = require('./data-field-query-resolver');
var {FunctionContext} = require('./functions');
var {isObjectDeep} = require('./is-object');
var {ValueFormatter} = require('./ValueFormatter');

/**
 * @classdesc Represents an event listener for validating not nullable fields. This listener is automatically  registered in all data models.
 * @class
 * @constructor
 */
function NotNullConstraintListener() {
    //
}
/**
 * Occurs before creating or updating a data object and validates not nullable fields.
 * @param {DataEventArgs|*} event - An object that represents the event arguments passed to this operation.
 * @param {Function} callback - A callback function that should be called at the end of this operation. The first argument may be an error if any occurred.
 */
NotNullConstraintListener.prototype.beforeSave = function(event, callback) {

    //find all attributes that have not null flag
    var attrs = event.model.attributes.filter(
        function(x) {
            return !x.primary && !(typeof x.nullable === 'undefined' ? true: x.nullable);
        });
    if (attrs.length===0) {
        callback(null);
        return 0;
    }
    async.eachSeries(attrs, function(attr, cb)
    {
        var name = attr.property || attr.name, value = event.target[name];
        if ((((value === null) || (value===undefined))  && (event.state===1))
            || ((value === null) && (typeof value!=='undefined') && (event.state === 2)))
        {
            var er = new NotNullError('A value is required.', null, event.model.name, attr.name);
            TraceUtils.debug(er);
            return cb(er);
        }
        else
            return cb();
    }, function(err) {
        callback(err);
    });
};

/**
 * @class
 * @constructor
 * @classdesc Represents an event listener for validating data model's unique constraints. This listener is automatically registered in all data models.
 */
function UniqueConstraintListener() {
    //
}
/**
 * Occurs before creating or updating a data object and validates the unique constraints of data model.
 * @param {DataEventArgs|*} event - An object that represents the event arguments passed to this operation.
 * @param {Function} callback - A callback function that should be called at the end of this operation. The first argument may be an error if any occurred.
 */
UniqueConstraintListener.prototype.beforeSave = function(event, callback) {

    //there are no constraints
    if (event.model.constraints===null)
    {
        //do nothing
        callback(null);
        return;
    }
    //get unique constraints
    var constraints = event.model.constraints.filter(function(x) {
        return (x.type==='unique');
    });
    if (constraints.length===0) {
        //do nothing
        callback(null);
        return;
    }
    async.eachSeries(constraints, function(constraint, cb)
    {
        /**
         * @type {DataQueryable}
         */
        var q;
        //build query
        for (var i = 0; i < constraint.fields.length; i++) {
            var attr = constraint.fields[i];
            var value = event.target[attr];
            if (typeof value === 'undefined') {
                cb(null);
                return;
            }
            //check field mapping
            var mapping = event.model.inferMapping(attr);
            var attribute = event.model.getAttribute(attr);
            if (mapping) {
                if (typeof event.target[attr] === 'object') {
                    value=event.target[attr][mapping.parentField];
                }
            }
            if (typeof value === 'undefined') {
                value = null;
            }
            if (attribute.type === 'Json' && value != null) {
                value = JSON.stringify(value);
            }
            if (q) {
                q.and(attr).equal(value);
            }
            else {
                q = event.model.where(attr).equal(value);
            }
        }
        if (typeof q === 'undefined')
            cb(null);
        else {
            q.silent().select(event.model.primaryKey).first(function(err, result) {
                if (err) {
                    cb(err);
                    return;
                }
                if (!result) {
                    //object does not exist
                    cb(null);
                }
                else {
                    var objectExists = true;
                    if (event.state===2) {
                        //validate object id (check if target object is the same with the returned object)
                        objectExists = (result[event.model.primaryKey]!== event.target[event.model.primaryKey]);
                    }
                    //if object already exists
                    if (objectExists) {
                        var er;
                        //so throw exception
                        if (constraint.description) {
                            er = new UniqueConstraintError(constraint.description, null, event.model.name);
                        }
                        else {
                            er = new UniqueConstraintError('Object already exists. A unique constraint violated.', null, event.model.name);
                        }
                        TraceUtils.debug(er);
                        return cb(er);
                    }
                    else {
                        return cb();
                    }
                }
            });
        }
    }, function(err) {
        callback(err);
    });
};

/**
 * @class
 * @constructor
 * @classdesc Represents an event listener which calculates field values. This listener is being registered for all data models.
 <p>
 A data field may have a calculation attribute.
 An instance of <a href="FunctionContext.html">FunctionContext</a> class will calculate this value by evaluating the expression provided.
 <pre class="prettyprint"><code>
 {
        "name": "modifiedBy",
        "title": "Modified By",
        "description": "Modified by user.",
        "type": "User",
        "calculation":"javascript:return this.user();"
    }
 </code></pre>
 <p>In the previous example modifiedBy field has a calculation for setting the user which performs the update operation.</p>
<p><strong>Note:</strong>FunctionContext class may be extended in order to allow applications to perform value calculations.</p>
 <pre class="prettyprint"><code>
    FunctionContext.prototype.myColor = function() {
        var deferred = Q.defer(),
            self = this;
        process.nextTick(function() {
            return self.context.model("UserColor")
                .where("user/name").equal(self.context.user.name)
                .select("color")
                .value().then(function(value) {
                    deferred.resolve(value);
                }).catch(function(err) {
                    deferred.reject(err);
                });
        });
        return deferred.promise;
    }
 </code></pre>
 <pre class="prettyprint"><code>
 {
        "name": "color",
        "title": "Color",
        "type": "Text",
        "calculation":"javascript:return this.myColor();"
    }
 </code></pre>
 <p>In this example a custom method of FunctionContext class gets the user's favourite color.</p>
 <p>This calculation may also be performed by setting the following promise expression:</p>
 <pre class="prettyprint"><code>
 {
        "name": "color",
        "title": "Color",
        "type": "Text",
        "calculation":"javascript:return this.context.model('UserColor').where('user/name').equal(this.context.user.name).select('color').value();"
    }
 </code></pre>
 </p>
 */
function CalculatedValueListener() {
    //
}
/**
 * Occurs before creating or updating a data object and calculates field values with the defined calculation expression.
 * @param {DataEventArgs} event - An object that represents the event arguments passed to this operation.
 * @param {Function} callback - A callback function that should be called at the end of this operation. The first argument may be an error if any occurred.
 */
CalculatedValueListener.prototype.beforeSave = function(event, callback) {
    //get function context
    var functionContext = new FunctionContext();
    _.assign(functionContext, event);
    functionContext.context = event.model.context;
    //find all attributes that have a default value
    var attrs = event.model.attributes.filter(function(x) { return (x.calculation!==undefined); });
    // create an instance of ValueFormatter
    var valueFormatter = new ValueFormatter(event.model.context, event.model, event.target);
    async.eachSeries(attrs, function(attr, cb) {
        var expr = attr.calculation;
        // use value formatter for object-like expressions
        if (isObjectDeep(expr)) {
            return valueFormatter.format(expr).then(function(result) {
                event.target[attr.name] = result;
                void cb();
            }).catch(function(err) {
                void cb(err);
            });
        }
        //validate expression
        if (typeof expr !== 'string') {
            event.target[attr.name] = expr;
            return cb();
        }
        //check javascript: keyword for code evaluation
        if (expr.indexOf('javascript:')===0) {
            //get expression
            var fnstr = expr.substring('javascript:'.length);
            //if expression starts with function add parenthesis (fo evaluation)
            if (fnstr.indexOf('function')===0) {
                fnstr = '('.concat(fnstr,')');
            }
            //if expression starts with return then normalize expression (surround with function() {} keyword)
            else if (fnstr.indexOf('return')===0) {
                fnstr = '(function() { '.concat(fnstr,'})');
            }
            var value = eval(fnstr);
            //if value is function
            if (typeof value === 'function') {
                //then call function against the target object
                var value1 = value.call(functionContext);
                if (typeof value1 !== 'undefined' && value1 !==null && typeof value1.then === 'function') {
                    //we have a promise, so we need to wait for answer
                    value1.then(function(result) {
                        //otherwise set result
                        event.target[attr.name] = result;
                        return cb();
                    }).catch(function(err) {
                        cb(err);
                    });
                }
                else {
                    event.target[attr.name] = value1;
                    return cb();
                }
            }
            else if (typeof value !== 'undefined' && value !==null && typeof value.then === 'function') {
                //we have a promise, so we need to wait for answer
                value.then(function(result) {
                    //otherwise set result
                    event.target[attr.name] = result;
                    return cb();
                }).catch(function(err) {
                    cb(err);
                });
            }
            else {
                //otherwise get value
                event.target[attr.name] = value;
                return cb();
            }
        }
        else if (expr.indexOf('fn:')===0) {
           return cb(new Error ('fn: syntax is deprecated.'));
        }
        else {
            functionContext.eval(expr, function(err, result) {
                if (err) {
                    cb(err);
                }
                else {
                    event.target[attr.name] = result;
                    cb(null);
                }
            });
        }

    }, function(err) {
        callback(err);
    });
};


/**
 * @classdesc Represents a data caching listener which is going to be used while executing queries against
 * data models where data caching is enabled. This listener is registered by default.
 <p>
      Data caching may be disabled when <a href="DataModel.html">DataModel</a>.caching property is set to 'none'. This is the default behaviour of a data model.
 </p>
 <pre class="prettyprint"><code>
 {
     "name": "Order", ... , "caching":"none"
     ...
 }
 </code></pre>
 <p>
 Data caching may be used when <a href="DataModel.html">DataModel</a>.caching property is set to 'always'.
 </p>
 <pre class="prettyprint"><code>
 {
     "name": "OrderStatus", ... , "caching":"always"
     ...
 }
 </code></pre>
 <p>
 Data caching may be conditionally enabled when <a href="DataModel.html">DataModel</a>.caching property is set to 'conditional'.
 </p>
 <pre class="prettyprint"><code>
 {
     "name": "Product", ... , "caching":"conditional"
     ...
 }
 </code></pre>
 <p>
 In this case, data caching will be used when an instance of <a href="DataQueryable.html">DataQueryable</a> class requests data with cache equal to true:
 </p>
 <pre class="prettyprint"><code>
    context.model('Product')
            .where('category').is('Laptops')
            .cache(true)
            .orderBy('name')
            .list().then(function(result) {
                done(null, result);
            }).catch(function(err) {
                done(err);
            });
 </code></pre>
 * @class
 * @constructor
 */
function DataCachingListener() {
    //
}
/**
 * Occurs before executing an query expression, validates data caching configuration and gets cached data.
 * @param {DataEventArgs|*} event - An object that represents the event arguments passed to this operation.
 * @param {Function} callback - A callback function that should be called at the end of this operation. The first argument may be an error if any occurred.
 */
DataCachingListener.prototype.beforeExecute = function(event, callback) {
    try {
        if (_.isNil(event)) {
            return callback();
        }
        //validate caching
        var caching = (event.model.caching==='always' || event.model.caching==='conditional');
        if (!caching) {
            return callback();
        }
        // get cache attribute
        var dataCache;
        if (event.emitter && typeof event.emitter.data === 'function') {
            dataCache = event.emitter.data('cache');
        }
        // if caching is enabled and cache attribute is defined
        if (typeof dataCache === 'boolean' && dataCache === false) {
            return callback();
        }
        //validate conditional caching
        if (event.model.caching==='conditional') {
            if (event.emitter && typeof event.emitter.data === 'function') {
                if (!event.emitter.data('cache')) {
                    return callback();
                }
            }
        }
        /**
         * @type {DataCacheStrategy}
         */
        var cache = event.model.context.getConfiguration().getStrategy(DataCacheStrategy);
        if (typeof cache === 'undefined' || cache === null) {
            return callback();
        }

        if (event.query && event.query.$select) {
            //create hash
            var hash;
            if (event.emitter && typeof event.emitter.toMD5 === 'function') {
                //get hash from emitter (DataQueryable)
                hash = event.emitter.toMD5();
            }
            else {
                //else calculate hash
                hash = TextUtils.toMD5({ query: event.query });
            }
            //format cache key
            var key = '/' + event.model.name + '/?query=' + hash;
            //calculate execution time (debug)
            var logTime = new Date().getTime();
            //query cache
            cache.get(key).then(function(result) {
                if (typeof result !== 'undefined') {
                    //delete expandables
                    if (event.emitter) {
                        delete event.emitter.$expand;
                    }
                    //set cached flag
                    event['cached'] = true;
                    //set execution default
                    event['result'] = result;
                    //log execution time (debug)
                    try {
                        if (process.env.NODE_ENV==='development') {
                            TraceUtils.log(sprintf('Cache (Execution Time:%sms):%s', (new Date()).getTime()-logTime, key));
                        }
                    }
                    catch(err) {
                        //
                    }
                    //exit
                    return callback();
                }
                else {
                    //do nothing and exit
                    return callback();
                }
            }).catch(function(err) {
                TraceUtils.log('DataCacheListener: An error occurred while trying to get cached data.');
                TraceUtils.log(err);
                return callback();
            });
        }
        else {
            return callback();
        }
    }
    catch (err) {
        return callback(err);
    }
};
/**
 * Occurs before executing an query expression, validates data caching configuration and stores data to cache
 * @param {DataEventArgs|*} event - An object that represents the event arguments passed to this operation.
 * @param {Function} callback - A callback function that should be called at the end of this operation. The first argument may be an error if any occurred.
 */
DataCachingListener.prototype.afterExecute = function(event, callback) {
    try {
        //validate caching
        var caching = (event.model.caching==='always' || event.model.caching==='conditional');
        if (!caching) {
            return callback();
        }
        // get cache attribute
        var dataCache;
        if (event.emitter && typeof event.emitter.data === 'function') {
            dataCache = event.emitter.data('cache');
        }
        // if caching is enabled and cache attribute is defined
        if (typeof dataCache === 'boolean' && dataCache === false) {
            return callback();
        }
        //validate conditional caching
        if (event.model.caching==='conditional') {
            if (event.emitter && typeof event.emitter.data === 'function') {
                if (!event.emitter.data('cache')) {
                    return callback();
                }
            }
        }

        /**
         * @type {DataCacheStrategy}
         */
        var cache = event.model.context.getConfiguration().getStrategy(DataCacheStrategy);
        if (typeof cache === 'undefined' || cache === null) {
            return callback();
        }

        if (event.query && event.query.$select) {
            if (typeof event.result !== 'undefined' && !event.cached) {
                //create hash
                var hash;
                if (event.emitter && typeof event.emitter.toMD5 === 'function') {
                    //get hash from emitter (DataQueryable)
                    hash = event.emitter.toMD5();
                }
                else {
                    //else calculate hash
                    hash = TextUtils.toMD5({ query: event.query });
                }
                var key = '/' + event.model.name + '/?query=' + hash;
                if (process.env.NODE_ENV==='development') {
                    TraceUtils.debug('DataCacheListener: Setting data to cache [' + key + ']');
                }
                cache.add(key, event.result);
                return callback();
            }
        }
        return callback();
    }
    catch(err) {
        return callback(err);
    }
};


/**
 * @class
 * @constructor
 * @classdesc Represents an event listener for calculating default values.
 * DefaultValueListener is one of the default listeners which are being registered for all data models.
 <p>
 A data field may have a default value attribute.
 An instance of <a href="FunctionContext.html">FunctionContext</a> class will calculate this value by evaluating the expression provided.
 The default value listener will process all fields of an inserted data object which have a default value expression and does not have a defined value.
 <pre class="prettyprint"><code>
 {
        "name": "createdBy",
        "title": "Created By",
        "type": "User",
        "value":"javascript:return this.user();",
        "readonly":true
    }
 </code></pre>
 <p></p>
 <p><strong>Note:</strong> FunctionContext class may be extended in order to allow applications to perform value calculations.</p>
 </p>
 */
function DefaultValueListener() {
    //
}
/**
 * Occurs before creating or updating a data object and calculates default values with the defined value expression.
 * @param {DataEventArgs|*} event - An object that represents the event arguments passed to this operation.
 * @param {Function} callback - A callback function that should be called at the end of this operation. The first argument may be an error if any occurred.
 */
DefaultValueListener.prototype.beforeSave = function(event, callback) {

    var state = typeof event.state === 'number' ? event.state : 0;
    if (state!==1)
    {
        return callback();
    }
    else {
        //get function context
        var functionContext = new FunctionContext();
        _.assign(functionContext, event);
        //find all attributes that have a default value
        var attrs = event.model.attributes.filter(function(x) { return (typeof x.value!== 'undefined'); });
        // create an instance of ValueFormatter
        var valueFormatter = new ValueFormatter(event.model.context, event.model, event.target);
        async.eachSeries(attrs, function(attr, cb) {
            try {
                var expr = attr.value;
                //if attribute is already defined
                if (typeof event.target[attr.name] !== 'undefined') {
                    //do nothing
                    return cb();
                }
                // use value formatter for object-like expressions
                if (isObjectDeep(expr)) {
                    return valueFormatter.format(expr).then(function(result) {
                        event.target[attr.name] = result;
                        void cb();
                    }).catch(function(err) {
                        void cb(err);
                    });
                }
                //validate expression
                if (typeof expr !== 'string') {
                    event.target[attr.name] = expr;
                    return cb();
                }
                //check javascript: keyword for code evaluation
                if (expr.indexOf('javascript:')===0) {
                    //get expression
                    var fnstr = expr.substring('javascript:'.length);
                    //if expression starts with function add parenthesis (fo evaluation)
                    if (fnstr.indexOf('function')===0) {
                        fnstr = '('.concat(fnstr,')');
                    }
                    //if expression starts with return then normalize expression (surround with function() {} keyword)
                    else if (fnstr.indexOf('return')===0) {
                        fnstr = '(function() { '.concat(fnstr,'})');
                    }
                    var value = eval(fnstr);
                    //if value is function
                    if (typeof value === 'function') {
                        //then call function against the target object
                        var value1 = value.call(functionContext);
                        if (typeof value1 !== 'undefined' && value1 !=null && typeof value1.then === 'function') {
                            //we have a promise, so we need to wait for answer
                            value1.then(function(result) {
                                //otherwise set result
                                event.target[attr.name] = result;
                                return cb();
                            }).catch(function(err) {
                                return cb(err);
                            });
                        }
                        else {
                            event.target[attr.name] = value1;
                            return cb();
                        }
                    }
                    else if (typeof value !== 'undefined' && value !=null && typeof value.then === 'function') {
                        //we have a promise, so we need to wait for answer
                        value.then(function(result) {
                            //otherwise set result
                            event.target[attr.name] = result;
                            return cb();
                        }).catch(function(err) {
                            return cb(err);
                        });
                    }
                    else {
                        //otherwise get value
                        event.target[attr.name] = value;
                        return cb();
                    }
                }
                else if (expr.indexOf('fn:')===0) {
                    return cb(new Error ('fn: syntax is deprecated.'));
                }
                else  {
                    functionContext.eval(expr, function(err, result) {
                        if (err) {
                            return cb(err);
                        }
                        event.target[attr.name] = result;
                        return cb();
                    });
                }
            }
            catch(err) {
                return cb(err);
            }
        }, function(err) {
            callback(err);
        });
    }
};

/**
 * @class
 * @constructor
 */
function DataModelCreateViewListener() {
    //
}
/**
 * Occurs after upgrading a data model.
 * @param {DataEventArgs} event - An object that represents the event arguments passed to this operation.
 * @param {Function} callback - A callback function that should be called at the end of this operation. The first argument may be an error if any occurred.
 */
DataModelCreateViewListener.prototype.afterUpgrade = function(event, callback) {

    var self = event.model,
        db = self.context.db;
    var view = self.viewAdapter, adapter = self.sourceAdapter;
    // if data model is a sealed model do nothing anb exit
    if (self.sealed) {
        return callback();
    }
    // if view adapter is the same with source adapter do nothing and exit
    if (view===adapter) {
        return callback();
    }
    // get base model
    var baseModel = self.base();
    var additionalExpand = [];
    // get array of fields
    var fields = [];
    try {
        fields = self.attributes.filter(function(x) {
            return (self.name=== x.model) && (!x.many);
        }).map(function(x) {
            if (x.readonly && x.query) {
                // resolve field expression (and additional joins)
                var expr = new DataFieldQueryResolver(self).resolve(x);
                if (expr) {
                    // hold additional joins
                    additionalExpand.push.apply(additionalExpand, expr.$expand);
                    // and return the resolved query expression for this field
                    return expr.$select;
                }
                // throw error
                throw new DataError('E_QUERY', 'The given field defines a custom query expression but it cannot be resolved', null, self.name, x.name);
            }
            return QueryField.select(x.name).from(adapter);
        });
    } catch (error) {
        return callback(error);
    }
    /**
     * @type {import("@themost/query").QueryExpression}
     */
    var q = QueryUtils.query(adapter).select(fields);
    var baseAdapter = null;
    var baseFields = [];
    // enumerate attributes of base model (if any)
    if (baseModel) {
        // get base adapter
        baseAdapter = baseModel.viewAdapter;
        // enumerate base model attributes
        baseModel.attributes.forEach(function(x) {
            //get all fields (except primary and one-to-many relations)
            if ((!x.primary) && (!x.many))
                baseFields.push(QueryField.select(x.name).from(baseAdapter))
        });
    }
    q.$expand = [];
    if (baseFields.length > 0) {
        var from = new QueryFieldRef(adapter, self.key().name);
        var to = new QueryFieldRef(baseAdapter, self.base().key().name);
        var addExpand = { $entity: { },$with:[] }
        addExpand.$entity[baseAdapter] = baseFields;
        addExpand.$with.push(from);
        addExpand.$with.push(to);
        q.$expand.push(addExpand);
    }
    for (var expand of additionalExpand) {
        var findIndex = q.$expand.findIndex(function(item) {
            return isEqual(expand, item);
        });
        if (findIndex < 0) {
            q.$expand.push(expand);
        }
    }
    //execute query
    return db.createView(view, q, function(err) {
        callback(err);
    });
};

/**
 * @class
 * @constructor
 */
function DataModelSeedListener() {
    //
}

/**
 * Occurs after upgrading a data model.
 * @param {DataEventArgs} event - An object that represents the event arguments passed to this operation.
 * @param {Function} callback - A callback function that should be called at the end of this operation. The first argument may be an error if any occurred.
 */
DataModelSeedListener.prototype.afterUpgrade = function(event, callback) {
    var self = event.model;
    try {
        /**
         * Gets items to be seeded
         * @type {Array}
         */
        var items = self['seed'];
        //if model has an array of items to be seeded
        if (_.isArray(items)) {
            if (items.length===0) {
                //if seed array is empty exit
                return callback();
            }
            //try to insert items if model does not have any record
            self.asQueryable().silent().flatten().count(function(err, count) {
                if (err) {
                    callback(err); return;
                }
                //if model has no data
                if (count===0) {
                    //set items state to new
                    items.forEach(function(x) { x.$state=1; });
                    self.silent().save(items, callback);
                }
                else {
                    //model was already seeded
                    return callback();
                }
            });
        }
        else {
            //do nothing and exit
            return callback();
        }
    }
    catch (e) {
        callback(e);
    }
};

/**
 * @class
 * @constructor
 */
function DataModelSubTypesListener() {
    //
}

/**
 * Occurs after upgrading a data model.
 * @param {DataEventArgs} event - An object that represents the event arguments passed to this operation.
 * @param {Function} callback - A callback function that should be called at the end of this operation. The first argument may be an error if any occurred.
 */
DataModelSubTypesListener.prototype.afterUpgrade = function(event, callback) {
    var self = event.model, context = event.model.context;
    try {
        self.getSubTypes().then(function(result) {
            if (result.length===0) { return callback(); }
            //enumerate sub types
            async.eachSeries(result, function(name, cb) {
                //get model
                var model = context.model(name);
                if (_.isNil(model)) { return cb(); }
                //if model is sealed do nothing
                if (model.sealed) { return cb(); }
                //create event arguments
                var ev = { model:model };
                //execute create view listener
                DataModelCreateViewListener.prototype.afterUpgrade(ev, cb);
            }, function(err) {
                return callback(err);
            });
        }).catch(function(err) {
            return callback(err);
        });
    }
    catch (e) {
        callback(e);
    }
};

module.exports = {
    NotNullConstraintListener,
    UniqueConstraintListener,
    CalculatedValueListener,
    DataCachingListener,
    DefaultValueListener,
    DataModelCreateViewListener,
    DataModelSeedListener,
    DataModelSubTypesListener
};