import { Subject } from "../Subject";
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import { OrmUtils } from "../../util/OrmUtils";
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import { EntityMetadata } from "../../metadata/EntityMetadata";
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/**
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* Builds operations needs to be executed for one-to-many relations of the given subjects.
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*
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* by example: post contains one-to-many relation with category in the property called "categories", e.g.
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* @OneToMany(type => Category, category => category.post) categories: Category[]
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* If user adds categories into the post and saves post we need to bind them.
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* This operation requires updation of category table since its owner of the relation and contains a join column.
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*
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* note: this class shares lot of things with OneToOneInverseSideOperationBuilder, so when you change this class
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* make sure to reflect changes there as well.
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*/
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var OneToManySubjectBuilder = /** @class */ (function () {
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// ---------------------------------------------------------------------
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// Constructor
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// ---------------------------------------------------------------------
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function OneToManySubjectBuilder(subjects) {
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this.subjects = subjects;
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}
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// ---------------------------------------------------------------------
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// Public Methods
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// ---------------------------------------------------------------------
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/**
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* Builds all required operations.
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*/
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OneToManySubjectBuilder.prototype.build = function () {
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var _this = this;
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this.subjects.forEach(function (subject) {
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subject.metadata.oneToManyRelations.forEach(function (relation) {
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// skip relations for which persistence is disabled
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if (relation.persistenceEnabled === false)
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return;
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_this.buildForSubjectRelation(subject, relation);
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});
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});
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};
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// ---------------------------------------------------------------------
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// Protected Methods
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// ---------------------------------------------------------------------
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/**
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* Builds operations for a given subject and relation.
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*
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* by example: subject is "post" entity we are saving here and relation is "categories" inside it here.
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*/
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OneToManySubjectBuilder.prototype.buildForSubjectRelation = function (subject, relation) {
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var _this = this;
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// prepare objects (relation id maps) for the database entity
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// note: subject.databaseEntity contains relations with loaded relation ids only
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// by example: since subject is a post, we are expecting to get all post's categories saved in the database here,
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// particularly their relation ids, e.g. category ids stored in the database
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var relatedEntityDatabaseRelationIds = [];
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if (subject.databaseEntity) { // related entities in the database can exist only if this entity (post) is saved
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relatedEntityDatabaseRelationIds = relation.getEntityValue(subject.databaseEntity);
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}
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// get related entities of persisted entity
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// by example: get categories from the passed to persist post entity
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var relatedEntities = relation.getEntityValue(subject.entity);
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if (relatedEntities === null) // we treat relations set to null as removed, so we don't skip it
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relatedEntities = [];
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if (relatedEntities === undefined) // if relation is undefined then nothing to update
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return;
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// extract only relation ids from the related entities, since we only need them for comparision
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// by example: extract from categories only relation ids (category id, or let's say category title, depend on join column options)
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var relatedPersistedEntityRelationIds = [];
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relatedEntities.forEach(function (relatedEntity) {
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var relationIdMap = relation.inverseEntityMetadata.getEntityIdMap(relatedEntity); // by example: relationIdMap is category.id map here, e.g. { id: ... }
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// try to find a subject of this related entity, maybe it was loaded or was marked for persistence
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var relatedEntitySubject = _this.subjects.find(function (subject) {
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return subject.entity === relatedEntity;
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});
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// if subject with entity was found take subject identifier as relation id map since it may contain extra properties resolved
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if (relatedEntitySubject)
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relationIdMap = relatedEntitySubject.identifier;
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// if relationIdMap is undefined then it means user binds object which is not saved in the database yet
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// by example: if post contains categories which does not have ids yet (because they are new)
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// it means they are always newly inserted and relation update operation always must be created for them
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// it does not make sense to perform difference operation for them for both add and remove actions
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if (!relationIdMap) {
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// we decided to remove this error because it brings complications when saving object with non-saved entities
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// if (!relatedEntitySubject)
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// throw new Error(`One-to-many relation "${relation.entityMetadata.name}.${relation.propertyPath}" contains ` +
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// `entities which do not exist in the database yet, thus they cannot be bind in the database. ` +
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// `Please setup cascade insertion or save entities before binding it.`);
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if (!relatedEntitySubject)
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return;
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// okay, so related subject exist and its marked for insertion, then add a new change map
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// by example: this will tell category to insert into its post relation our post we are working with
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// relatedEntitySubject is newly inserted CategorySubject
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// relation.inverseRelation is ManyToOne relation inside Category
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// subject is Post needs to be inserted into Category
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relatedEntitySubject.changeMaps.push({
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relation: relation.inverseRelation,
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value: subject
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});
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return;
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}
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// check if this binding really exist in the database
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// by example: find our category if its already bind in the database
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var relationIdInDatabaseSubjectRelation = relatedEntityDatabaseRelationIds.find(function (relatedDatabaseEntityRelationId) {
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return OrmUtils.deepCompare(relationIdMap, relatedDatabaseEntityRelationId);
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});
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// if relationIdMap DOES NOT exist in the subject's relation in the database it means its a new relation and we need to "bind" them
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// by example: this will tell category to insert into its post relation our post we are working with
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// relatedEntitySubject is newly inserted CategorySubject
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// relation.inverseRelation is ManyToOne relation inside Category
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// subject is Post needs to be inserted into Category
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if (!relationIdInDatabaseSubjectRelation) {
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// if there is no relatedEntitySubject then it means "category" wasn't persisted,
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// but since we are going to update "category" table (since its an owning side of relation with join column)
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// we create a new subject here:
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if (!relatedEntitySubject) {
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relatedEntitySubject = new Subject({
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metadata: relation.inverseEntityMetadata,
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parentSubject: subject,
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canBeUpdated: true,
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identifier: relationIdMap
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});
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_this.subjects.push(relatedEntitySubject);
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}
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relatedEntitySubject.changeMaps.push({
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relation: relation.inverseRelation,
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value: subject
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});
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}
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// if related entity has relation id then we add it to the list of relation ids
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// this list will be used later to compare with database relation ids to find a difference
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// what exist in this array and does not exist in the database are newly inserted relations
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// what does not exist in this array, but exist in the database are removed relations
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// removed relations are set to null from inverse side of relation
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relatedPersistedEntityRelationIds.push(relationIdMap);
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});
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// find what related entities were added and what were removed based on difference between what we save and what database has
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EntityMetadata
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.difference(relatedEntityDatabaseRelationIds, relatedPersistedEntityRelationIds)
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.forEach(function (removedRelatedEntityRelationId) {
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// todo: probably we can improve this in the future by finding entity with column those values,
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// todo: maybe it was already in persistence process. This is possible due to unique requirements of join columns
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// we create a new subject which operations will be executed in subject operation executor
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var removedRelatedEntitySubject = new Subject({
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metadata: relation.inverseEntityMetadata,
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parentSubject: subject,
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canBeUpdated: true,
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identifier: removedRelatedEntityRelationId,
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changeMaps: [{
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relation: relation.inverseRelation,
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value: null
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}]
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});
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_this.subjects.push(removedRelatedEntitySubject);
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});
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};
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return OneToManySubjectBuilder;
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}());
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export { OneToManySubjectBuilder };
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//# sourceMappingURL=OneToManySubjectBuilder.js.map
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