@env0/dynamo-easy/dist/_esm2015/dynamo/request/read-many.request.js

DynamoDB client for NodeJS and browser with a fluent api to build requests. We take care of the type mapping between JS and DynamoDB, customizable trough typescript decorators.

import { fetchAll } from '../../helper/fetch-all.function';
import { promiseTap } from '../../helper/promise-tap.function';
import { fromDb } from '../../mapper/mapper';
import { and } from '../expression/logical-operator/and.function';
import { addExpression } from '../expression/param-util';
import { addCondition } from '../expression/request-expression-builder';
import { StandardRequest } from './standard.request';
/**
 * abstract class for query and scan request classes.
 */
export class ReadManyRequest extends StandardRequest {
    constructor(dynamoDBWrapper, modelClazz) {
        super(dynamoDBWrapper, modelClazz);
        this.mapFromDb = (output) => {
            const response = Object.assign({}, output);
            response.Items = (output.Items || []).map(item => fromDb(item, this.modelClazz));
            return response;
        };
    }
    /**
     *
     * @param key A map representing the start id which is included in next call, if null is delivered
     * startKey will be removed from params
     */
    exclusiveStartKey(key) {
        // TODO ENHANCEMENT exclusiveStartKey(item: Partial<T>)
        if (key) {
            this.params.ExclusiveStartKey = key;
        }
        else {
            delete this.params.ExclusiveStartKey;
        }
        return this;
    }
    /**
     * query items on the given index.
     */
    index(indexName) {
        const index = this.metadata.getIndex(indexName);
        if (index) {
            this.secondaryIndex = index;
            this.params.IndexName = indexName;
        }
        else {
            throw new Error(`there is no index with name <${indexName}> defined for model ${this.modelClazz.name}`);
        }
        return this;
    }
    /**
     * set Limit to params - The maximum number of items to evaluate (not necessarily the number of matching items)
     */
    limit(limit) {
        if (limit === ReadManyRequest.INFINITE_LIMIT) {
            delete this.params.Limit;
        }
        else {
            if (limit !== null && limit !== undefined && limit > 0) {
                this.params.Limit = limit;
            }
            else {
                throw new Error('limit must be a valid positive number');
            }
        }
        return this;
    }
    whereAttribute(attributePath) {
        return addCondition('FilterExpression', attributePath, this, this.metadata);
    }
    /**
     * add one or multiple conditions.
     * @example req.where( attribute('age').eq(23) )
     * @example req.where( or( attribute('age').lt(18), attribute('age').gt(65) ) )
     */
    where(...conditionDefFns) {
        const condition = and(...conditionDefFns)(undefined, this.metadata);
        addExpression('FilterExpression', condition, this.params);
        return this;
    }
    /**
     * execute the request and return the raw response (without parsing the attributes to js objects)
     */
    execNoMap() {
        this.logger.debug('request (noMap)', this.params);
        return this.doRequest(this.params)
            .then(promiseTap(response => this.logger.debug('response', response)));
    }
    /**
     * Execute with Limit: 1 to read the first item only
     */
    execSingle() {
        // do not alter the params on the instance but add the additional 'Limit' param to a copy.
        // otherwise a follow-up request with the very same request-object would be wrong
        const params = Object.assign({}, this.params, { Limit: 1 });
        this.logger.debug('single request', params);
        return this.doRequest(params)
            .then(promiseTap(response => this.logger.debug('response', response)))
            .then(this.mapFromDb)
            .then(r => (r.Items && r.Items.length ? r.Items[0] : null))
            .then(promiseTap(item => this.logger.debug('mapped item', item)));
    }
    /**
     * Execute with Select: 'Count' to count the items.
     */
    execCount() {
        // do not alter the params on the instance but add the additional 'Select' param to a copy.
        // otherwise a follow-up request with the very same request-object would be wrong
        const params = Object.assign({}, this.params, { Select: 'COUNT' });
        this.logger.debug('count request', params);
        return this.doRequest(params)
            .then(promiseTap(response => this.logger.debug('response', response)))
            .then(response => response.Count || 0)
            .then(promiseTap(count => this.logger.debug('count', count)));
    }
    /**
     * execute request and return the parsed items
     */
    exec() {
        this.logger.debug('request', this.params);
        return this.doRequest(this.params)
            .then(promiseTap(response => this.logger.debug('response', response)))
            .then(this.mapFromDb)
            .then(r => r.Items)
            .then(promiseTap(items => this.logger.debug('mapped items', items)));
    }
    /**
     * execute request and return the full response with the parsed items
     */
    execFullResponse() {
        this.logger.debug('request', this.params);
        return this.doRequest(this.params)
            .then(promiseTap(response => this.logger.debug('response', response)))
            .then(this.mapFromDb)
            .then(promiseTap(response => this.logger.debug('mapped items', response.Items)));
    }
    /**
     * fetches all pages. may uses all provisionedOutput, therefore for client side use cases rather use pagedDatasource (exec)
     */
    execFetchAll() {
        return fetchAll(this);
    }
}
/** Infinite limit will remove the Limit param from request params when calling ReadManyRequest.limit(ReadManyRequest.INFINITE_LIMIT) */
ReadManyRequest.INFINITE_LIMIT = -1;
//# sourceMappingURL=read-many.request.js.map