Merge pull request #94 from shiftcode/#78-transact-write-items

#78 transact write items

Author: michaelwittwer

README.md

@@ -187,7 +187,7 @@ When one of the following decorators is present, the value is always mapped to a
 We only support the native Date type and you need to explicitly mark a property to be a Date by using the @Date() decorator\
 (which is basically just syntactic sugar for @CustomMapper(TheDateMapper)).\
 If you want to use a different type for the @Date decorator (eg. Moment) you need to define a custom mapper and provide it to the dynamo easy config like this:\
-`updateDynamoEasyConfig({ dateMapper: MomentMapper })`\
+`updateDynamoEasyConfig({ dateMapper: MomentMapper })`
 
 
 A mapper for moment dates could look like this:
@@ -219,7 +219,7 @@ export const MomentMapper: MapperForType<moment.Moment, StringAttribute> = {
 
 
 ## Enum
-Enum values are persisted as Numbers (index of enum) or string if string value was given.
+Enum values are persisted as Numbers (index of enum or assigned value) or string if string value was assigned.
 
 # Request API
 To start making requests create an instance of [DynamoStore](https://shiftcode.github.io/dynamo-easy/classes/_dynamo_dynamo_store_.dynamostore.html) and execute the desired operation using the provided api.
@@ -237,6 +237,54 @@ We support the following dynamodb operations with a fluent api:
 
 There is always the possibility to access the Params object directly to add values which are not covered with our api.
 
+## non table tied requests
+Currently two type of requests exists which are not tied to one table/model and therefore are not created from a DynamoStore instance.
+
+### BatchGet
+
+There are two scenarios for a batch get item request. One is requesting multiple items from one table by id and the other is requesting multiple items by id from multiple
+tables. The first scenario is support using DynamoStore.batchGet() the second one can be achieved by using the [BatchGetRequest](https://shiftcode.github.io/dynamo-easy/classes/_dynamo_batchget_batch_get_request_.batchgetrequest.html) class.
+
+```typescript
+  import { BatchGetRequest } from '@shiftcoders/dynamo-easy'
+  new BatchGetRequest()
+      // table with simple primary key
+    .forModel(YourModelWithPartitionKey, [{ id: 'myId' }], /* consistentRead */ true)
+    // table with composite primary key (sortkey is optional)
+    .forModel(YourModelWithCompositeKey, [{ id: 'myId', creationDate: new Date('2018-01-01') }])
+    .exec().subscribe(response => {
+       // an object where the items are mapped to the table name 
+     })
+```
+### TransactWriteRequest
+Create transactions for all-or-nothing operations with [TransactWriteRequest](https://shiftcode.github.io/dynamo-easy/classes/_dynamo_transactwrite_transact_write_request_.transactwriterequest.html) across one or more tables.
+The different operations are:
+* [TransactConditionCheck](https://shiftcode.github.io/dynamo-easy/classes/_dynamo_transactwrite_transact_condition_check_.transactconditioncheck.html)
+* [TransactPut](https://shiftcode.github.io/dynamo-easy/classes/_dynamo_transactwrite_transact_put_.transactput.html)
+* [TransactDelete](https://shiftcode.github.io/dynamo-easy/classes/_dynamo_transactwrite_transact_delete_.transactdelete.html)
+* [TransactUpdate](https://shiftcode.github.io/dynamo-easy/classes/_dynamo_transactwrite_transact_update_.transactupdate.html)
+
+The transaction operations can optionally check for prerequisite conditions that must be satisfied before making updates. 
+For conditions not involving a an item to write on, use the TransactConditionCheck.
+
+```typescript
+  import { TransactWriteRequest, TransactConditionCheck, TransactDelete, TransactPut, attribute } from '@shiftcoders/dynamo-easy'
+  
+  new TransactWriteRequest()
+    .transact(
+      new TransactConditionCheck(YourModelWithPartitionKey, 'check-ID').onlyIf(attribute('age').gt(18)),
+      new TransactDelete(YourModelWithCompositeKey, 'the-partition-key', 'the-sort-key'),
+      new TransactPut(YourCustomModel, { id: 'put-ID-1', age: 21 }).ifNotExists(),
+    )
+    .returnItemCollectionMetrics('SIZE')
+    .returnConsumedCapacity('TOTAL')
+    .execFullResponse()
+    .subscribe(resp => {
+      console.log(resp.ItemCollectionMetrics)
+      console.log(resp.ConsumedCapacity)
+    })
+```
+
 # Authentication
 In a real world scenario you'll have some kind of authentication to protect your dynamodb ressources. You can customize on how to authenticate when providing a custom
 SessionValidityEnsurer function to the DynamoStore when creating a new instance.
@@ -245,7 +293,7 @@ The default implementation is a no-op function.
 ## Session Validity Ensurer
 Here is an example of an implementation using amazon cognito
 
-```javascript
+```typescript
 function sessionValidityEnsurer(): Observable<boolean> {
   return Observable.of(this.isLoggedIn())
     .switchMap(isLoggedIn => {
@@ -295,30 +343,6 @@ these are the accessor rules for nested attribute types
 - [n] — for list elements
 - . (dot) — for map elements
 
-## Pagination 
-TODO
-
-## BatchGet
-
-There are two scenarios for a batch get item request. One is requesting multiple items from one table by id and the other is requesting multiple items by id from multiple
-tables.
-The first scenario is support using DynamoStore.batchGet() the second one must be implemented using the BatchGetItem class.
-
-```typescript
-const request = new BatchRequest()
-
-// table with simple primary key
-request.forModel(MyModelClass, ['idValue', 'idValue2'])
-
-// table with composite primary key (sortkey is optional)
-request.forModel(MyOtherModelClass, [{partitionKey: 'id', sortKey: 'sortKeyValue'}])
-
-request.exec().subscribe(response => {
-  // an object where the items are mapped to the table name 
-})
-
-```
-
 # Development
 
 ## NPM scripts
@@ -331,7 +355,7 @@ request.exec().subscribe(response => {
  - `npm run commit`: Commit using conventional commit style ([husky](https://github.com/typicode/husky) will tell you to use it if you haven't :wink:)
 
 ## Automatic releases
-Use the npm comand `npm run commit`, which is a convenient way to create conventional commits. Those messages are used to run [semantic releases](https://github.com/semantic-release/semantic-release),
+Use the npm comand `npm run commity`, which is a convenient way to create conventional commits. Those messages are used to run [semantic releases](https://github.com/semantic-release/semantic-release),
 which publishes our code automatically on github and npm, plus generates automatically a changelog. This setup is highly influenced by [Kent C. Dodds course on egghead.io](https://egghead.io/courses/how-to-write-an-open-source-javascript-library)
 
 ## Git Hooks
@@ -354,7 +378,7 @@ We use 2 git hooks:
 Made with :heart: by [@michaelwittwer](https://github.com/michaelwittwer) and all these wonderful contributors ([emoji key](https://github.com/kentcdodds/all-contributors#emoji-key)):
 
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-| [<img src="https://avatars1.githubusercontent.com/u/8394182?v=4" width="100px;"/><br /><sub>Michael Wittwer</sub>](https://www.shiftcode.ch)<br />[💻](https://github.com/shiftcode/dynamo-easy/commits?author=michaelwittwer "Code") [📖](https://github.com/shiftcode/dynamo-easy/commits?author=michaelwittwer "Documentation") [⚠️](https://github.com/shiftcode/dynamo-easy/commits?author=michaelwittwer "Tests") | [<img src="https://avatars2.githubusercontent.com/u/8321523?s=460&v=4" width="100px;"/><br /><sub>Michael Lieberherr</sub>](https://www.shiftcode.ch)<br />[💻](https://github.com/shiftcode/dynamo-easy/commits?author=michaellieberherrr "Code") [📖](https://github.com/shiftcode/dynamo-easy/commits?author=michaellieberherrr "Documentation") [⚠️](https://github.com/shiftcode/dynamo-easy/commits?author=michaellieberherrr "Tests") | [<img src="https://avatars3.githubusercontent.com/u/37636934?s=460&v=4" width="100px;"/><br /><sub>Simon Mumenthaler</sub>](https://www.shiftcode.ch)<br />[💻](https://github.com/shiftcode/dynamo-easy/commits?author=simonmumenthaler "Code") [⚠️](https://github.com/shiftcode/dynamo-easy/commits?author=simonmumenthaler "Tests") |
+| [<img src="https://avatars1.githubusercontent.com/u/8394182?v=4" width="100px;"/><br /><sub>Michael Wittwer</sub>](https://www.shiftcode.ch)<br />[💻](https://github.com/shiftcode/dynamo-easy/commits?author=michaelwittwer "Code") [📖](https://github.com/shiftcode/dynamo-easy/commits?author=michaelwittwer "Documentation") [⚠️](https://github.com/shiftcode/dynamo-easy/commits?author=michaelwittwer "Tests") | [<img src="https://avatars2.githubusercontent.com/u/8321523?s=460&v=4" width="100px;"/><br /><sub>Michael Lieberherr</sub>](https://www.shiftcode.ch)<br />[💻](https://github.com/shiftcode/dynamo-easy/commits?author=michaellieberherrr "Code") [📖](https://github.com/shiftcode/dynamo-easy/commits?author=michaellieberherrr "Documentation") [⚠️](https://github.com/shiftcode/dynamo-easy/commits?author=michaellieberherrr "Tests") | [<img src="https://avatars3.githubusercontent.com/u/37636934?s=460&v=4" width="100px;"/><br /><sub>Simon Mumenthaler</sub>](https://www.shiftcode.ch)<br />[💻](https://github.com/shiftcode/dynamo-easy/commits?author=simonmumenthaler "Code") [📖](https://github.com/shiftcode/dynamo-easy/commits?author=simonmumenthaler "Documentation") [⚠️](https://github.com/shiftcode/dynamo-easy/commits?author=simonmumenthaler "Tests") |
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