betterddb/dist/builders/get-builder.js

A definition-based DynamoDB wrapper library that provides a schema-driven and fully typesafe DAL.

/* eslint-disable no-unused-vars */
import {} from "../betterddb.js";
import { TransactGetCommand, GetCommand } from "@aws-sdk/lib-dynamodb";
import {} from "@aws-sdk/client-dynamodb";
export class GetBuilder {
    parent;
    key;
    projectionExpression;
    expressionAttributeNames = {};
    extraTransactItems = [];
    constructor(parent, key) {
        this.parent = parent;
        this.key = key;
    }
    /**
     * Specify a projection by providing an array of attribute names.
     */
    withProjection(attributes) {
        this.projectionExpression = attributes
            .map((attr) => `#${String(attr)}`)
            .join(", ");
        for (const attr of attributes) {
            this.expressionAttributeNames[`#${String(attr)}`] = String(attr);
        }
        return this;
    }
    async execute() {
        if (this.extraTransactItems.length > 0) {
            // Build our update transaction item.
            const myTransactItem = this.toTransactGet();
            // Combine with extra transaction items.
            const allItems = [...this.extraTransactItems, myTransactItem];
            await this.parent.getClient().send(new TransactGetCommand({
                TransactItems: allItems,
            }));
            // After transaction, retrieve the updated item.
            const result = await this.parent.get(this.key).execute();
            return result;
        }
        else {
            const params = {
                TableName: this.parent.getTableName(),
                Key: this.parent.buildKey(this.key),
            };
            if (this.projectionExpression) {
                params.ProjectionExpression = this.projectionExpression;
                params.ExpressionAttributeNames = this.expressionAttributeNames;
            }
            const result = await this.parent.getClient().send(new GetCommand(params));
            if (!result.Item)
                return null;
            return this.parent.getSchema().parse(result.Item);
        }
    }
    transactGet(ops) {
        if (Array.isArray(ops)) {
            this.extraTransactItems.push(...ops);
        }
        else {
            this.extraTransactItems.push(ops);
        }
        return this;
    }
    toTransactGet() {
        const getItem = {
            TableName: this.parent.getTableName(),
            Key: this.parent.buildKey(this.key),
        };
        if (this.projectionExpression) {
            getItem.ProjectionExpression = this.projectionExpression;
            getItem.ExpressionAttributeNames = this.expressionAttributeNames;
        }
        return { Get: getItem };
    }
}
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