CDS Change Log

provide the ChangeLog best practice for SAP CAP nodejs runtime

Get Started

package.json

{
  "cds": {
    "plugins": {
      "cds-change-log": {
        "impl": "cds-change-log"
      }
    }
  }
}

entity.cds

• MUST using from 'cds-change-log' statement in CDS model
• MUST annotating @cds.changelog.enabled on elements
• MUST annotating at the root/raw entity level, annotations on projection/view will not work
• MUST have at least one PRIMARY KEY

using {cap.community.common} from 'cds-change-log'

entity People : cuid, managed, customManaged {
  Name       : String(255);
  Age        : Integer;
  changeLogs : Association to many common.ChangeLog
                 on  changeLogs.entityKey  = $self.ID
                 and changeLogs.entityName = 'People';
}

// mark in entity and field elements level
// annotation in another place, you can put it into entity definition directly
annotate People with {
  Age  @cds.changelog.enabled;
  Name @cds.changelog.enabled;
};

create and update objects

let response = await axios.post("/sample/Peoples", { Name: "Theo Sun 2", Age: 39 })
const { ID } = response.data
await axios.patch(`/sample/Peoples(${ID})`, { Name: "Theo Sun 9", Age: 12 })

generated change logs

[
  {
    ID: "595b3604-d7dd-434f-962c-1e70e92bd775",
    actionAt: "2022-03-17T04:20:41.402Z",
    actionBy: "anonymous",
    entityName: "People",
    entityKey: "0e926ff2-53ad-4cd9-9569-ad2147dad0bc",
    action: "Create",
    Items: [
      {
        sequence: 0,
        Parent_ID: "595b3604-d7dd-434f-962c-1e70e92bd775",
        attributeKey: "Name",
        attributeNewValue: "Theo Sun 2",
        attributeOldValue: null,
      },
      {
        sequence: 1,
        Parent_ID: "595b3604-d7dd-434f-962c-1e70e92bd775",
        attributeKey: "Age",
        attributeNewValue: "39",
        attributeOldValue: null,
      },
    ],
  },
  {
    ID: "55bca8b8-1e79-4c9b-8bc9-1a013bf3cf39",
    actionAt: "2022-03-17T04:20:41.461Z",
    actionBy: "anonymous",
    entityName: "People",
    entityKey: "0e926ff2-53ad-4cd9-9569-ad2147dad0bc",
    action: "Update",
    Items: [
      {
        sequence: 0,
        Parent_ID: "55bca8b8-1e79-4c9b-8bc9-1a013bf3cf39",
        attributeKey: "Name",
        attributeNewValue: "Theo Sun 9",
        attributeOldValue: "Theo Sun 2",
      },
      {
        sequence: 1,
        Parent_ID: "55bca8b8-1e79-4c9b-8bc9-1a013bf3cf39",
        attributeKey: "Age",
        attributeNewValue: "12",
        attributeOldValue: "39",
      },
    ],
  },
]

Custom Type Primary Key

if you want to use Integer or other cds built-in type as primary key

entity.cds

@cds.changelog.enabled
entity Order : managed { // a sample entity
  key ID     : Integer; // use Integer as key, not out-of-box UUID
      @cds.changelog.enabled
      Amount : Decimal;
};

extension.cds

// remember using this file from your project root
using {cap.community.common.ChangeLog} from 'cds-change-log';

extend ChangeLog with {

  // add a new column 'entityKeyInteger' for integer key
  @cds.changelog.extension.entityKey
  // this column will be used when entity use `Integer` as primary key
  // MUST add the `cds.` prefix for built-in types
  @cds.changelog.extension.for.type : cds.Integer 
  entityKeyInteger : Integer;
  
};

Multi Primary Keys on target entity

if you want to manually specify the data storage for entity keys

entity.cds

@cds.changelog.enabled
entity PeopleOrderForProduct {
      // store key to ChangeLog.entityKeyInteger
      @cds.changelog.extension.key.target : 'entityKeyInteger'
  key OrderID  : Integer;
      // store key to ChangeLog.entityKey
      @cds.changelog.extension.key.target : 'entityKey'
  key PeopleID : UUID;
      @cds.changelog.enabled
      Amount   : Decimal;
}

Features

• [x] single CUD OData requests
• [x] multi CUD CQL
• [x] all Update/Delete CQL (without where)
• [x] aspect support
• [x] localization support
• [x] custom type key (e.g. Integer) support
  • [x] metadata cache
• [x] multi primary key support
• [x] extension field support
• [ ] draft mode (draftActivate)
  • [x] simple single entity
  • [ ] localization
• [ ] key relation cache
• [ ] built-in FE UI Annotations
• [ ] save change logs in async mode
• [ ] benchmark test
• [ ] subscribe change log event
• [ ] validation at startup
• [ ] skip/warn log for Blob
• [ ] secondary storage like mongo/s3
• [ ] readable identifier support
• [ ] association/composition support
  • [ ] annotation @cds.changelog.to
• [ ] Samples
  • [ ] localized data sample
  • [ ] for fiori elements
  • [ ] rows to columns table records

CHANGELOG

LICENSE