@env0/dynamo-easy
Version:
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.
316 lines • 12.1 kB
JavaScript
import * as tslib_1 from "tslib";
/**
* @module mapper
*/
import { v4 as uuidv4 } from 'uuid';
import { hasSortKey } from '../decorator/metadata/metadata';
import { metadataForModel } from '../decorator/metadata/metadata-for-model.function';
import { hasType } from '../decorator/metadata/property-metadata.model';
import { BooleanMapper } from './for-type/boolean.mapper';
import { CollectionMapper } from './for-type/collection.mapper';
import { NullMapper } from './for-type/null.mapper';
import { NumberMapper } from './for-type/number.mapper';
import { ObjectMapper } from './for-type/object.mapper';
import { StringMapper } from './for-type/string.mapper';
import { Binary } from './type/binary.type';
import { NullType } from './type/null.type';
import { UndefinedType } from './type/undefined.type';
import { getPropertyPath, typeOf, typeOfFromDb } from './util';
/**
* @hidden
*/
var mapperForType = new Map();
/**
* mapps an item according to given model constructor [its meta data] to attributes
*/
export function toDb(item, modelConstructor) {
var mapped = {};
if (modelConstructor) {
var metadata = metadataForModel(modelConstructor);
/*
* initialize possible properties with auto generated uuid
*/
if (metadata) {
metadata.getKeysWithUUID().forEach(function (propertyMetadata) {
if (!Reflect.get(item, propertyMetadata.name)) {
Reflect.set(item, propertyMetadata.name, uuidv4());
}
});
}
}
item = getES6ClassProperties(item);
var propertyNames = Object.getOwnPropertyNames(item) || [];
propertyNames.forEach(function (propertyKey) {
/*
* 1) get the value of the property
*/
var propertyValue = getPropertyValue(item, propertyKey);
var attributeValue;
if (propertyValue === undefined || propertyValue === null) {
// noop ignore because we can't map it
}
else {
/*
* 2) decide how to map the property depending on type or value
*/
var propertyMetadata = void 0;
if (modelConstructor) {
propertyMetadata = metadataForModel(modelConstructor).forProperty(propertyKey);
}
if (propertyMetadata) {
if (propertyMetadata.transient) {
// 3a_1) skip transient property
}
else {
// 3a_2) property metadata is defined and property is not marked not transient
attributeValue = toDbOne(propertyValue, getPropertyPath(modelConstructor, propertyKey), propertyMetadata);
}
}
else {
// 3b) no metadata found
attributeValue = toDbOne(propertyValue, getPropertyPath(modelConstructor, propertyKey));
}
if (attributeValue === undefined) {
// no-op transient field, just ignore it
}
else if (attributeValue === null) {
// empty values will be ignored too
}
else {
;
mapped[propertyMetadata ? propertyMetadata.nameDb : propertyKey] = attributeValue;
}
}
});
return mapped;
}
export function toDbOne(propertyValue, propertyPathOrMetadata, propertyMetadata) {
var propertyPath = propertyPathOrMetadata && typeof propertyPathOrMetadata === 'string' ? propertyPathOrMetadata : null;
propertyMetadata = propertyPathOrMetadata && typeof propertyPathOrMetadata !== 'string' ? propertyPathOrMetadata : propertyMetadata;
var explicitType = hasType(propertyMetadata)
? propertyMetadata.typeInfo.type
: null;
var type = explicitType || typeOf(propertyValue, propertyPath);
var mapper = propertyMetadata && propertyMetadata.mapper ? propertyMetadata.mapper() : forType(type);
var attrValue = explicitType
? mapper.toDb(propertyValue, propertyMetadata)
: mapper.toDb(propertyValue);
// some basic validation
if (propertyMetadata && propertyMetadata.key) {
if (attrValue === null) {
throw new Error(propertyMetadata.name.toString() + " is null but is a " + propertyMetadata.key.type + " key");
}
if (!('S' in attrValue) && !('N' in attrValue) && !('B' in attrValue)) {
throw new Error("DynamoDb only allows string, number or binary type for RANGE and HASH key. Make sure to define a custom mapper for '" + propertyMetadata.name.toString() + "' which returns a string, number or binary value for partition key, type " + type + " cannot be used as partition key, value = " + JSON.stringify(propertyValue));
}
}
return attrValue;
}
/**
* @hidden
*/
function testForKey(p) {
return !!p.key;
}
/**
* returns the function for the given ModelConstructor to create the AttributeMap with HASH (and RANGE) Key of a given item.
* @param modelConstructor
*/
export function createToKeyFn(modelConstructor) {
var metadata = metadataForModel(modelConstructor);
var properties = metadata.modelOptions.properties;
if (!properties) {
throw new Error('metadata properties is not defined');
}
var keyProperties = properties.filter(testForKey);
return function (item) {
return keyProperties.reduce(function (key, propMeta) {
if (item[propMeta.name] === null || item[propMeta.name] === undefined) {
throw new Error("there is no value for property " + propMeta.name.toString() + " but is " + propMeta.key.type + " key");
}
var propertyValue = getPropertyValue(item, propMeta.name);
key[propMeta.nameDb] = toDbOne(propertyValue, propMeta);
return key;
}, {});
};
}
/**
* creates toKeyFn and applies item to it.
* @see {@link createToKeyFn}
*/
export function toKey(item, modelConstructor) {
return createToKeyFn(modelConstructor)(item);
}
/**
* @hidden
*/
export function createKeyAttributes(metadata, partitionKey, sortKey) {
var _a;
var partitionKeyProp = metadata.getPartitionKey();
var partitionKeyMetadata = metadata.forProperty(partitionKeyProp);
if (!partitionKeyMetadata) {
throw new Error('metadata for partition key must be defined');
}
var keyAttributeMap = (_a = {},
_a[partitionKeyMetadata.nameDb] = toDbOne(partitionKey, partitionKeyMetadata),
_a);
if (hasSortKey(metadata)) {
if (sortKey === null || sortKey === undefined) {
throw new Error("please provide the sort key for attribute " + metadata.getSortKey());
}
var sortKeyProp = metadata.getSortKey();
var sortKeyMetadata = metadata.forProperty(sortKeyProp);
if (!sortKeyMetadata) {
throw new Error('metadata for sort key must be defined');
}
keyAttributeMap[sortKeyMetadata.nameDb] = toDbOne(sortKey, sortKeyMetadata);
}
return keyAttributeMap;
}
/**
* parses attributes to a js item according to the given model constructor [its meta data]
*/
export function fromDb(attributeMap, modelConstructor) {
var model = {};
Object.getOwnPropertyNames(attributeMap).forEach(function (attributeName) {
/*
* 1) get the value of the property
*/
var attributeValue = attributeMap[attributeName];
/*
* 2) decide how to map the property depending on type or value
*/
var modelValue;
var propertyMetadata;
if (modelConstructor) {
propertyMetadata = metadataForModel(modelConstructor).forProperty(attributeName);
}
if (propertyMetadata) {
if (propertyMetadata.transient) {
// skip transient property
}
else {
/*
* 3a) property metadata is defined
*/
if (propertyMetadata && propertyMetadata.mapper) {
// custom mapper
modelValue = propertyMetadata.mapper().fromDb(attributeValue, propertyMetadata);
}
else {
modelValue = fromDbOne(attributeValue, propertyMetadata);
}
}
}
else {
modelValue = fromDbOne(attributeValue);
}
if (modelValue !== null && modelValue !== undefined) {
Reflect.set(model, propertyMetadata ? propertyMetadata.name : attributeName, modelValue);
}
});
return model;
}
/**
* parses an attribute to a js value according to the given property metadata
*/
export function fromDbOne(attributeValue, propertyMetadata) {
var explicitType = hasType(propertyMetadata) ? propertyMetadata.typeInfo.type : null;
var type = explicitType || typeOfFromDb(attributeValue);
if (explicitType) {
return forType(type).fromDb(attributeValue, propertyMetadata);
}
else {
return forType(type).fromDb(attributeValue);
}
}
/**
* @hidden
*/
export function forType(type) {
var mapper = mapperForType.get(type);
if (!mapper) {
switch (type) {
case String:
mapper = StringMapper;
break;
case Number:
mapper = NumberMapper;
break;
case Boolean:
mapper = BooleanMapper;
break;
case Map:
// Maps support complex types as keys, we only support String & Number as Keys, otherwise a .toString() method should be implemented,
// so we now how to save a key
// mapperForType = new MapMapper()
throw new Error('Map is not supported to be mapped for now');
case Array:
mapper = CollectionMapper;
break;
case Set:
mapper = CollectionMapper;
break;
case NullType:
mapper = NullMapper;
break;
case Binary:
throw new Error('no mapper for binary type implemented yet');
case UndefinedType:
mapper = ObjectMapper;
break;
case Object:
default:
// return ObjectMapper as default to support nested @Model decorated classes (nested complex classes)
// just note that the property still needs @Property decoration to get the metadata of the complex type
mapper = ObjectMapper;
}
mapperForType.set(type, mapper);
}
return mapper;
}
/**
* @hidden
*/
export function getPropertyValue(item, propertyKey) {
var propertyDescriptor = Object.getOwnPropertyDescriptor(item, propertyKey);
// use get accessor if available otherwise use value property of descriptor
if (propertyDescriptor) {
if (propertyDescriptor.get) {
return propertyDescriptor.get();
}
else {
return propertyDescriptor.value;
}
}
else {
throw new Error("there is no property descriptor for item " + JSON.stringify(item) + " and property key " + propertyKey);
}
}
/**
* @hidden
*/
function getES6ClassProperties(item) {
var e_1, _a;
var jsonObj = tslib_1.__assign({}, item);
var proto = Object.getPrototypeOf(item);
try {
for (var _b = tslib_1.__values(Object.getOwnPropertyNames(proto)), _c = _b.next(); !_c.done; _c = _b.next()) {
var key = _c.value;
var desc = Object.getOwnPropertyDescriptor(proto, key);
var hasGetter = desc && typeof desc.get === 'function';
if (hasGetter) {
jsonObj[key] = item[key];
}
}
}
catch (e_1_1) { e_1 = { error: e_1_1 }; }
finally {
try {
if (_c && !_c.done && (_a = _b.return)) _a.call(_b);
}
finally { if (e_1) throw e_1.error; }
}
return jsonObj;
}
//# sourceMappingURL=mapper.js.map