Model define default value can not work

[tears330]

neogma/src/ModelOps/ModelOps.ts

Line 487 in c237b20

const validationResult = revalidator.validate(

Here is my model schema:

{
      id: {
        type: 'string',
        uniqueItems: true,
        required: true,
      },
      name: {
        type: 'string',
        required: true,
        uniqueItems: true,
      },
      createdAt: {
        type: 'number',
        required: true,
        default: Date.now
      },
      updatedAt: {
        type: 'number',
        required: true,
        default: Date.now
      },
    }

neogma model use revalidator to check the value , but revalidator has this issue flatiron/revalidator#85 , the default field does't implement.

How about use class-validator & class-transformer to replace the schema implement ?

Good

• save a lot template code ( define interface & default validate rules )
• got more feature (type transform & default value)

Bad

• will cause a break change

[themetalfleece]

In the beginning I was using class-validator, but it was complicating things a lot (i.e. I had to befine the class anyway, then pass it to ModelFactory). So I ended up using a simple object validator.

For starters, I'd be a good idea for me to fork revalidator, implement default, merge the typings into it so they're build-in, and use it for neogma.
In the future, I could reconsider using class-validator and class-transformer.

For your issue, you could add a Before Create Hook which sets the default value.

YourModel.beforeCreate = (instance) => {
    if (!instance.createdAt) {
        instance.createdAt = Date.now;
    }
    if (!instance.updatedAt) {
        instance.updatedAt= Date.now;
    }
};

Of course this is not quite the same as a default value, as it runs only before saving an instance (which should work in your case).

Also, in case you want to use an actual neo4j date, you could do the following:

import { neo4jDriver } from 'neogma';

type YourProperties = {
    createdAt: neo4jDriver.DateTime<any>;
}

// in schema validation:
{            
    createdAt: {
        type: 'any',
        required: true,
        conform: (v) => neo4jDriver.isDateTime(v),
    }
}

// to create the date
const nowDateTime = neo4jDriver.types.DateTime.fromStandardDate(
    new Date(),
);

I don't know if there's an easier way 😅 Although I could implement an automatic transformation of neo4j <-> js Dates on an Instance level.

[tears330]

Sorry for late reply 🙈. Use beforeCreate hook can resolve my current problem.

I just want to use the basic timestamp to mark the node. It's too complex when I try to use neo4j Date Object ( have to implement the adapter for two different data structure on application layer ) .

If u want to use class-validator and class-transformer , how about consider using the typeorm style like that ?

@Node()
@Relation(() => Order)
export class User {
    @Property()
    id: number;

    @Property()
    firstName: string;

    @Property()
    lastName: string;

    @Property()
    age: number;

    @CreateDateProperty()
    createdAt: Date;
}

And load the entity file like

createConnection({
    url: 'bolt://127.0.0.1:7687',
    username: 'neo4j',
    password: 'neo4j',
    entities: [
        __dirname + "/entity/*.js"
    ]
}).then(connection => {
    // here you can start to work with your entities
}).catch(error => console.log(error));

[themetalfleece]

Thanks for all that info! It'll come in handy when I consider replacing revalidator

[tejo-ak]

I like the use of decorators as it helps the schema definition clean. The current way is so verbose, but it works. So, I do support decorator, but without removing the current style for backward compatibility.