feat: add list of aliases to note entity

One of the aliases can be primary for each note, but all can be used to get information from the apis.

Signed-off-by: Philip Molares <philip.molares@udo.edu>

docs/content/dev/db-schema.plantuml

@@ -6,13 +6,20 @@ entity "note" {
   *id : uuid <<generated>>
   --
   publicId: text
-  alias : text
   *viewCount : number
   *ownerId : uuid <<FK user>>
   description: text
   title: text
 }
 
+entity "alias" {
+  *id: uuid <<generated>>
+  ---
+  name: text
+  ' If the alias is primary. Can be NULL, which means it's not primary
+  primary: boolean
+}
+
 entity "user" {
   *id : uuid <<generated>>
   --
@@ -169,6 +176,7 @@ media_upload "0..*"  -- "1" note
 note "1" -d- "1..*" revision
 note "1" - "0..*" history_entry
 note "0..*" -l- "0..*" tag
+note "1" - "0..*" alias
 note "0..*" -- "0..*" group
 user "1..*" -- "0..*" group
 

src/notes/alias.entity.ts

@@ -0,0 +1,63 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import {
+  Column,
+  Entity,
+  ManyToOne,
+  PrimaryGeneratedColumn,
+  Unique,
+} from 'typeorm';
+
+import { Note } from './note.entity';
+import { PrimaryValueTransformer } from './primary.value-transformer';
+
+@Entity()
+@Unique('Only one primary alias per note', ['note', 'primary'])
+export class Alias {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  /**
+   * the actual alias
+   */
+  @Column({
+    nullable: false,
+    unique: true,
+  })
+  name: string;
+
+  /**
+   * Is this alias the primary alias, by which people access the note?
+   */
+  @Column({
+    /*
+      Because of the @Unique at the top of this entity, this field must be saved as null instead of false in the DB.
+      If a non-primary alias would be saved with `primary: false` it would only be possible to have one non-primary and one primary alias.
+      But a nullable field does not have such problems.
+      This way the DB keeps track that one note really only has one primary alias.
+      */
+    comment:
+      'This field tells you if this is the primary alias of the note. If this field is null, that means this alias is not primary.',
+    nullable: true,
+    transformer: new PrimaryValueTransformer(),
+  })
+  primary: boolean;
+
+  @ManyToOne((_) => Note, (note) => note.aliases, {
+    onDelete: 'CASCADE', // This deletes the Alias, when the associated Note is deleted
+  })
+  note: Note;
+
+  // eslint-disable-next-line @typescript-eslint/no-empty-function
+  private constructor() {}
+
+  static create(name: string, primary = false): Alias {
+    const alias = new Alias();
+    alias.name = name;
+    alias.primary = primary;
+    return alias;
+  }
+}

src/notes/note-metadata.dto.ts

@@ -25,13 +25,19 @@ export class NoteMetadataDto {
   id: string;
 
   /**
-   * Alias of the note
-   * Can be null
+   * All aliases of the note (including the primaryAlias)
+   */
+  @IsArray()
+  @IsString({ each: true })
+  @ApiProperty()
+  aliases: string[];
+
+  /**
+   * The primary alias of the note
    */
   @IsString()
-  @IsOptional()
-  @ApiPropertyOptional()
-  alias: string | null;
+  @ApiProperty()
+  primaryAlias: string | null;
 
   /**
    * Title of the note

src/notes/note.entity.ts

@@ -19,6 +19,7 @@ import { NoteGroupPermission } from '../permissions/note-group-permission.entity
 import { NoteUserPermission } from '../permissions/note-user-permission.entity';
 import { Revision } from '../revisions/revision.entity';
 import { User } from '../users/user.entity';
+import { Alias } from './alias.entity';
 import { Tag } from './tag.entity';
 import { generatePublicId } from './utils';
 
@@ -28,12 +29,12 @@ export class Note {
   id: string;
   @Column({ type: 'text' })
   publicId: string;
-  @Column({
-    unique: true,
-    nullable: true,
-    type: 'text',
-  })
-  alias: string | null;
+  @OneToMany(
+    (_) => Alias,
+    (alias) => alias.note,
+    { cascade: true }, // This ensures that embedded Aliases are automatically saved to the database
+  )
+  aliases: Alias[];
   @OneToMany(
     (_) => NoteGroupPermission,
     (groupPermission) => groupPermission.note,
@@ -84,7 +85,7 @@ export class Note {
   public static create(owner?: User, alias?: string): Note {
     const newNote = new Note();
     newNote.publicId = generatePublicId();
-    newNote.alias = alias ?? null;
+    newNote.aliases = alias ? [Alias.create(alias, true)] : [];
     newNote.viewCount = 0;
     newNote.owner = owner ?? null;
     newNote.userPermissions = [];

src/notes/notes.module.ts

@@ -14,6 +14,7 @@ import { NoteUserPermission } from '../permissions/note-user-permission.entity';
 import { RevisionsModule } from '../revisions/revisions.module';
 import { User } from '../users/user.entity';
 import { UsersModule } from '../users/users.module';
+import { Alias } from './alias.entity';
 import { Note } from './note.entity';
 import { NotesService } from './notes.service';
 import { Tag } from './tag.entity';
@@ -26,6 +27,7 @@ import { Tag } from './tag.entity';
       NoteGroupPermission,
       NoteUserPermission,
       User,
+      Alias,
     ]),
     forwardRef(() => RevisionsModule),
     UsersModule,

src/notes/primary.value-transformer.ts

@@ -0,0 +1,22 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { ValueTransformer } from 'typeorm';
+
+export class PrimaryValueTransformer implements ValueTransformer {
+  from(value: boolean | null): boolean {
+    if (value === null) {
+      return false;
+    }
+    return value;
+  }
+
+  to(value: boolean): boolean | null {
+    if (!value) {
+      return null;
+    }
+    return value;
+  }
+}