NestJS Insert a Comment into a user blog post - postgresql

Question

I have an app where an user can create a list of Recipes and each Recipe can have multiple comments that many users can post.
This is what im trying to do:
I have a comments Enitity:
import {
Entity,
PrimaryGeneratedColumn,
Column,
BeforeUpdate,
ManyToOne,
JoinColumn,
ManyToMany,
} from 'typeorm';
import { UserEntity } from 'src/user/models/user.entity';
import { RecipeEntity } from 'src/recipe/model/recipe-entry.entity';
import { User } from 'src/user/models/user.interface';
#Entity('comments_entry')
export class CommentsEntity {
#PrimaryGeneratedColumn()
id: number;
#Column({ type: 'timestamp', default: () => 'CURRENT_TIMESTAMP' })
createdAt: Date;
#Column({ type: 'timestamp', default: () => 'CURRENT_TIMESTAMP' })
updatedAt: Date;
#BeforeUpdate()
updateTimestamp() {
this.updatedAt = new Date();
}
#ManyToOne(
type => UserEntity,
user => user.username,
)
author: UserEntity;
#Column()
recipe_id: number;
#Column()
author_id: number;
#ManyToOne(
type => RecipeEntity,
recipe => recipe.comment,
)
#JoinColumn({ name: 'recipe_id', referencedColumnName: 'id' })
comment: RecipeEntity;
}
Linked to a Recipe entity:
import {
Entity,
PrimaryGeneratedColumn,
Column,
BeforeUpdate,
ManyToOne,
JoinColumn,
OneToMany,
JoinTable,
ManyToMany,
} from 'typeorm';
import { UserEntity } from 'src/user/models/user.entity';
import { CommentsEntity } from 'src/comments/model/comments.entity';
#Entity('recipe_entry')
export class RecipeEntity {
#PrimaryGeneratedColumn()
id: number;
#Column()
title: string;
#Column()
slug: string;
#Column('text', { array: true, nullable: true })
ingr: string[];
#Column({ default: '' })
description: string;
#Column({ default: '' })
body: string;
#Column({ type: 'timestamp', default: () => 'CURRENT_TIMESTAMP' })
createdAt: Date;
#Column({ type: 'timestamp', default: () => 'CURRENT_TIMESTAMP' })
updatedAt: Date;
#BeforeUpdate()
updateTimestamp() {
this.updatedAt = new Date();
}
#Column({ nullable: true })
headerImage: string;
#Column({ nullable: true })
publishedDate: Date;
#Column({ nullable: true })
isPublished: boolean;
#Column()
user_id: number;
#ManyToOne(
type => UserEntity,
user => user.recipeEntries,
)
#JoinColumn({ name: 'user_id', referencedColumnName: 'id' })
author: UserEntity;
#Column({ default: 0 })
totalWeight: number;
#Column('text', { array: true, default: '{}' })
dietLabels: string[];
#Column({ default: 0 })
calorieQuantity: number;
#Column({ default: 0 })
proteinQuantity: number;
#Column({ default: 0 })
carbQuantity: number;
#Column({ default: 0 })
fatQuantity: number;
#Column({ default: 0 })
sugarQuantity: number;
#Column('text', { array: true, nullable: true })
likes: string[];
#Column({ default: false, nullable: true })
isLiked: boolean;
#OneToMany(
type => CommentsEntity,
comments => comments.comment,
)
comment: CommentsEntity[];
}
Linked to an User entity:
import {
Entity,
PrimaryGeneratedColumn,
Column,
BeforeInsert,
OneToMany,
} from 'typeorm';
import { UserRole } from './user.interface';
import { RecipeEntity } from 'src/recipe/model/recipe-entry.entity';
import { CommentsEntity } from 'src/comments/model/comments.entity';
#Entity()
export class UserEntity {
#PrimaryGeneratedColumn()
id: number;
#Column()
name: string;
#Column({ unique: true })
username: string;
#Column({ unique: true })
email: string;
#Column({ select: false })
password: string;
#Column({ type: 'enum', enum: UserRole, default: UserRole.USER })
role: UserRole;
#Column({ nullable: true })
profileImage: string;
#Column({ default: false, nullable: true })
favourite: boolean;
#OneToMany(
type => RecipeEntity,
recipeEntity => recipeEntity.author,
)
recipeEntries: RecipeEntity[];
#OneToMany(
type => CommentsEntity,
recipeEntryEntity => recipeEntryEntity.author,
)
commentEntries: CommentsEntity[];
#BeforeInsert()
emailToLowerCase() {
this.email = this.email.toLowerCase();
}
}
As an user i can post recipes. But im failing to add comments on specific recipes.
2 errors:
When i create a Recipe with some hardcoded comments, the users and recipe table gets filled but the comments_entry table is empty.
And im failing to implement the method to add comments to a specific recipe.
Controller:
#UseGuards(JwtAuthGuard)
#Post('recipe/:id')
createComment(
#Param() params,
#Body() comment: string,
#Request() req,
): Observable<RecipeEntry> {
const user = req.user;
const id = params.id;
return this.recipeService.createComment(user, id, comment);
}
createComment(id: number, commentEntry: string): Observable<RecipeEntry> {
return from(this.findOne(id)).pipe(
switchMap((recipe: RecipeEntry) => {
const newComment = recipe.comment.push(commentEntry);
return this.recipeRepository.save(newComment);
}),
);
}
Type 'Observable<DeepPartial[]>' is not assignable to type 'Observable'.
Property 'comment' is missing in type 'DeepPartial[]' but required in type 'RecipeEntry'.ts(2322)
recipe-entry.interface.ts(18, 3): 'comment' is declared here.
Any help?

Answer 1

Can't build working example but may be would helpful:
Redo your relations (I simplified entities for example, but you should use full:) ):
#Entity('comments_entry')
export class CommentsEntity {
#Column()
authorId: number;
#ManyToOne(type => UserEntity, user => user.id)
author: UserEntity;
#ManyToOne(type => RecipeEntity, recipe => recipe.id)
recipe: RecipeEntity;
}
#Entity('recipe_entry')
export class RecipeEntity {
#Column()
authorId: number;
#ManyToOne(type => UserEntity, user => user.id)
author: UserEntity;
#OneToMany(type => CommentsEntity, comment => comment.recipe)
comments: CommentsEntity[];
}
#Entity('user_entry')
export class UserEntity {
#OneToMany( type => RecipeEntity, recipe => recipe.author)
recipes: RecipeEntity[];
#OneToMany(type => CommentsEntity, comment => comment.author)
comments: CommentsEntity[];
}
RecipeDto something like:
RecipeDto: {
authorId: number | string,
comments: CommentDto[],
****other recipe data
}
create new Recipe:
createRecipe(recipeDto: RecipeDto): Observable<RecipeEntry> {
const { comments, authorId } = recipeDto;
if(comments) {
const commentPromises = comments.map(async comment => {
comment.authorId = authorId;
return await this.commentRepository.save(comment);
});
recipeDto.comments = await Promise.all(commentPromises);
}
return await this.recipeRepository.save(recipeDto);
}

Answer 2

If I understood correctly, you are trying that:
One User --> Many Recipes
One User --> Many Comments
One Recipe --> Many Comments
Your entities seems right.
Normally a typeorm repository returns a promise and not an observable.
You need to convert it to an Observable.
And at the moment you are trying to store a comment in the recipeRepo. You should save the whole recipe. And before you have to save the comment in the comment repo (if you are not working with cascades).
Something like this:
createComment(id: number, commentEntry: string): Observable<RecipeEntry> {
return from(this.findOne(id)).pipe(
switchMap((recipe: RecipeEntry) => {
return from(this.commentRepository.save(newComment)).pipe(
map(com: Comment) => {
recipe.comment.push(com);
return from(this.recipeRepository.save(recipe));
}
)
);
}
If you enable cascades, you can do this in only one call.