schema-evolution

Schema Evolution

Investigates schema evolution patterns

Getting Started

Needed dependencies

$ node --version
v16.13.1

$ npm --version
8.1.2

Using NVM for node version management

nvm use v16.13.1

Build

cd FluidPatterns
npm run clean
npm install --legacy-peer-deps
npm run build

Run

Terminal 1

npx tinylicious

Terminal 2

cd FluidPatterns/apps/schema-evolution
npm start

Schema Versioning Example

// evolvable-1.0.0.ts
export default  {
    typeid: "hex:evolvable-1.0.0",
    inherits: "NamedProperty",
    properties: [
        { id: "numA", typeid: "Int32" },
        { id: "strB", typeid: "String" },
    ],
};

// evolvable-1.0.1.ts
export default  {
    typeid: "hex:evolvable-1.0.1",
    inherits: "NamedProperty",
    properties: [
        { id: "numA", typeid: "Int32" },
        { id: "strB", typeid: "String" },
        { id: "strC", typeid: "String" },
    ],
};

// evolvable-1.0.2.ts 
// this is breaking the rule that for Minor change, 
// attributes should only be added
export default  {
    typeid: "hex:evolvable-1.0.2",
    inherits: "NamedProperty",
    properties: [
        { id: "numA", typeid: "Int32" },
        { id: "strC", typeid: "String" },
        { id: "strD", typeid: "String" },
    ],
};


// evolvable-2.0.0.ts
export default  {
    typeid: "hex:evolvable-2.0.0",
    inherits: "NamedProperty",
    properties: [
        { id: "numA", typeid: "Int32" },
        { id: "strB", typeid: "String" },
        { id: "strF", typeid: "String" },
        { id: "strG", typeid: "String" },
    ],
};

Registration Example

// application
import evolvableSchema100 from "./evolvable-1.0.0";
import evolvableSchema101 from "./evolvable-1.0.1";
import evolvableSchema102 from "./evolvable-1.0.2";
import evolvableSchema200 from "./evolvable-2.0.0";  
 ...

PropertyFactory.register(Object.values(
  [evolvableSchema100,evolvableSchema101,evolvableSchema102
  ,evolvableSchema103,evolvableSchema200]));

Minor Versions Example

  // configuration for hex:evolvable-1.0.0 and using UpgradeType.MINOR
  // applies configuration for all hex:evolvable-1.x.x
  fluidBinder.defineRepresentation("view", "hex:evolvable-1.0.0", (property) => {
    return new Evolvable(property.getTypeid(),evolvableRenderer);
  },{upgradeType: UpgradeType.MINOR});
  fluidBinder.defineDataBinding("view", "hex:evolvable-1.0.0", EvolvableBinding,{upgradeType: UpgradeType.MINOR});
  fluidBinder.activateDataBinding("view");

Partial Configurations Example

fluidBinder.defineDataBinding("view", "hex:evolvable-1.0.0", FirstEvolvableBinding,{upgradeType: UpgradeType.MINOR});
fluidBinder.defineDataBinding("view", "hex:evolvable-1.3.0", NextEvolvableBinding,{upgradeType: UpgradeType.MINOR});

Schema Evolution

• Do not evolve data all data

• Evolve data, which need the attributes which came with the new version

  • Application should be backward compatible

  • It should not fail if the old version is loaded

• Evolution can only be done by rewriting the data

  • The old data of the old type versions are loaded to application

  • The instance of new type is instantiated

  • The old attributes are copied to the new instance

  • The new attributes are filled as needed

  • The new instance replaces the old instance in the PropertyDDS

Schema Evolution Example

function to101(containerId: string | undefined, rootProp: NodeProperty, workspace: Workspace) {  
  let numA = (rootProp.resolvePath("evolvable.numA") as ValueProperty)?.getValue();
  if(!numA){
      numA = -1;
  }
  let strC = (rootProp.resolvePath("evolvable.strC") as ValueProperty)?.getValue();
  if(!strC){
    strC = "-";
  }
  let strB = (rootProp.resolvePath("evolvable.strB") as ValueProperty)?.getValue();
  if(!strB){
    strB = "-";
  }
  removeEvolvable(rootProp);
  rootProp.insert("evolvable", PropertyFactory.create("hex:evolvable-1.0.1", undefined, 
      { "numA": numA, "strB": strB, "strC": strC }));
  workspace.commit();
}

Disclaimer

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.

This project may contain Microsoft trademarks or logos for Microsoft projects, products, or services. Use of these trademarks or logos must follow Microsoft’s Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship.