https://github.com/yuforium/activity-streams

Activity Streams validation for Typescript
https://github.com/yuforium/activity-streams

activitypub activitystreams activitystreams-vocabulary

Last synced: 4 days ago
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Activity Streams validation for Typescript

• Host: GitHub
• URL: https://github.com/yuforium/activity-streams
• Owner: yuforium
• License: mit
• Created: 2020-10-19T15:34:10.000Z (about 4 years ago)
• Default Branch: main
• Last Pushed: 2024-04-07T21:28:58.000Z (7 months ago)
• Last Synced: 2024-05-23T04:38:33.294Z (6 months ago)
• Topics: activitypub, activitystreams, activitystreams-vocabulary
• Language: TypeScript
• Homepage:
• Size: 529 KB
• Stars: 14
• Watchers: 2
• Forks: 0
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# @yuforium/activity-streams

_Activity Streams Validator and Transformer_

## Getting Started

```sh

npm i --save \

  @yuforium/activity-streams \

  class-validator class-transformer \

  reflect-metadata

```

## Using Built-In Classes

Use built in classes to do validation using class-validator:

```typescript

import 'reflect-metadata';

import { Note } from '@yuforium/activity-streams';

import { validate } from 'class-validator';

const note = new Note();

async function validateNote() {

  let errors = await validate(note);

  if (errors.length > 0) {

    console.log('the note is invalid');

  }

  else {

    console.log('the note is valid');

  }

}

note.id = 'https://yuforium.com/users/chris/note-123';

validateNote(); // the note is valid

note.id = 'invalid, id must be a valid URL';

validateNote(); // the note is invalid

```

## Defining Custom Validation Rules

You can define your own validation rules by extending the built in classes or initializing your own using one of several methods using a base type (such as a link, object, activity, or collection):

```typescript

import { Expose } from 'class-transformer';

import { IsString, validate } from 'class-validator';

import { ActivityStreams } from '@yuforium/activity-streams';

import 'reflect-metadata';

// Creates a CustomNote type class as an Activity Streams Object

class CustomNote extends ActivityStreams.object('CustomNote') {

  @Expose()

  @IsString({each: true})

  public customField: string | string[];

};

// Add this to the built-in transformer

ActivityStreams.transformer.add(CustomNote);

// new instance of CustomNote

const custom: CustomNote = ActivityStreams.transform({

  type: 'CustomNote',

  customField: 5 // invalid, must be a string

});

// will get error "each value in customField must be a string"

validate(custom).then(errors => {

  errors.forEach(error => { console.log(error) });

});

```

## Composite Transformation

In addition to supporting custom classes, multiple types may be defined and interpolated from the `transform()` method.

```typescript

import { Expose } from 'class-transformer';

import { IsString, validate } from 'class-validator';

import { ActivityStreams } from '@yuforium/activity-streams';

import 'reflect-metadata';

// Creates CustomNote class as an Activity Streams Object

class CustomNote extends ActivityStreams.object('CustomNote') {

  @Expose()

  @IsString({each: true})

  public customField: string | string[];

};

// Add this to the built in transformer

ActivityStreams.transformer.add(CustomNote);

// new instance of CustomNote

const custom = ActivityStreams.transform({

  type: 'CustomNote',

  customField: 5 // invalid, must be a string

});

// will get error "each value in customField must be a string"

validate(custom).then(errors => {

  errors.forEach(error => { console.log(error) });

});

```

## Requiring Optional Fields

Many fields in the Activity Streams specification are optional, but you may want to make them required your own validation purposes.

Extend the classes you need and then use the `@IsRequired()` decorator for these fields.

_my-note.ts_

```typescript

import { Note, IsRequired } from '@yuforium/activity-streams';

export class MyNote extends Note {

  // content field is now required

  @IsRequired()

  public content;

}

```

_validate.ts_

```typescript

import { MyNote } from './my-note';

const note = new MyNote();

validate(note); // fails

note.content = "If you can dodge a wrench, you can dodge a ball.";

validate(note); // works

```