Understanding and Using Relations in Strapi

In this article, we will look into the relational fields in Strapi to see how we can utilize them to establish relationships in our models.

What is Strapi?

Strapi is an open-source Node.js headless CMS(Content Management System) based on Node.js used to develop APIs(RESTful and GraphQL APIs) and build the APIs content. The APIs in Strapi are built in the form of collections or single types.

A collection in Strapi will create and expose the endpoints on all the HTTP verbs. For example, if we have a blog collection. Strapi will create the following endpoints based on the collection:

• blog GET: This will get all the blog entries from the endpoint.
• blog POST: This will create a new blog post from the endpoint.
• blog/:documentId GET: This will return the blog post with the document ID :documentId.
• blog/:documentId DELETE: This will delete the blog post with the document ID :documentId from the endpoint.

Strapi creates all those APIs for us. We can then add content to the collection via the admin panel or the Strapi API.

Internally, Strapi is powered by Koajs, and its default database is SQLite, where it persists the content we add to the collections and single-types.

Now, you will learn about relations in database models and establish the relations in Strapi collections.

Relations in Database Fields and Strapi

The database contains tables, columns, and records. Now, relationships can be defined in the database tables. In Strapi, we can use relations to create links between our Content Types. This relationship is like a pointer or reference. They point to data in a table that depicts what they contain.

There are types of relationships we can establish in Strapi:

• One-to-one (1:1)
• One-to-Many
• Many-to-Many
• One-Way
• Many-way
• Polymorphic

Strapi One-to-one relationship (1:1)

In this Strapi one-to-one relationship, a column in a table points to only one column in another table.

For example, in a Student table, a studentId column can point to a StudentInfo table. A column in the StudentInfo table, studentId points back to the Student table. So here, the Student table is associated with one and only one record in the StudentInfo table. We can fetch a student's info from the Student table, and we can fetch a student from the StudentInfo table. That's a one-to-one relationship.

Strapi One-to-Many Relationship

This relation involves a table pointing to several or many tables. A column in table A can point to several tables(B, C, D), these tables, in turn, point to table A. Also, each table (A, B, C, D) can hold one or more records of the column in table A.

For example, let's say we have a Company table. This table holds the list of all the companies in a system. We can create an Employee table to hold the name of an employee. Now, we can add a companyId column to the Employee table, and this companyId will point to the Company table.

Now a Company table can point to many employee records in the Employee table. Also, each record in the Employee table points back to a record in the Company table. The relation here is Strapi one-to-many relationship.

Strapi Many-to-Many Relationship

Strapi many-to-many relationship involves a column in a table pointing to many records in another table and a column in another table pointing to many records in the first table. For example, many doctors can be associated with many hospitals.

Strapi One-Way Relationship

This relationship involves a column pointing or linking to another column in a table. The thing here is that the other column does not point back to the "pointing" column. One-way relation is similar to One-to-One relation but differs because the column being "pointed" does not link back to the pointing column.

For example, in a User table, A detailsId column in the User table can point to a Details table. This means that the details of a user are in the detailsId column in the User table and the details are stored in the Details table.

So we see that the User table points to only one table, which is the Details table. The relationship is one-way. There is no column in the Details table that points back to the User table.

Strapi Many-way Relationship

This relation involves a column in a table pointing to many records in another table. The records being pointed to does not point back or link back to the record.

For example, a User table has a column carId that points to a Car table. The carId can point to many records in the Car table but the Car record does not point back to the User table, this relationship is a Strapi many-way relationship.

Polymorphic

This relationship involves a column in a table that can link to different columns in other tables. In a polymorphic relationship, a model/table can be associated with different models/tables. In other relationships we have seen, it is mainly between a table and another table, not more than three tables are involved in the relationship. But in a polymorphic relationship, multiple tables are involved.

For example, a Tire table holds can be linked and have links to a Toyota table, Mercedes table, etc. So a Toyota can relate to the same Tire as a Mercedes. We have seen all the relations we have. The below sections will explain and show how we can set the relations from both the Strapi admin UI and a Strapi project.

Where are relations set in Strapi?

Relationship links can be set in the Admin panel and manually from the generated Strapi project.

Via Strapi Admin Panel

Relations can be set in Strapi's Collection types, Single types, and Components. The relation is set when adding fields to our Collection, Single collection, or Component type. The relation field is selected:

Another UI is displayed in the modal:

This is where we set the relations between the current model we are creating and an existing model.

We have two big boxes in the above picture, the left box is the current model we are creating, and the right box is the model the current model will be having relations with. We can click on the dropdown icon to select the model we want to link relations within the right box.

The smaller boxes with icons are the relations we can establish between the two models in the bigger boxes.

Let's look at the smaller boxes starting from the left.

• The first box represents the has one relation.

It establishes a one-way relation between content types in Strapi.

• The second box is has one and belongs to one.

It links two content types in a one-to-one way relationship.

• The third box is belongs to many.

It links two content types in a one-to-many relation. The content type in the left-bigger box will have a field that links to many records in the content type that is in the right-bigger box. The field in the content type in the right-bigger box will have a field that links to a single record in the left-content type.

• The fourth box is has many.

This one links two content types in a many-to-one relation. Here, the content type at the left-bigger box has a field that links to many records to the content type at the right-bigger box. It is the reverse of the belongs to many boxes.

• The fifth box is has and belongs to many.

This box links two content types in a many-to-many relationship. Both content types in the bigger boxes will have a field that links many records to each other.

• The sixth box is has many.

It links two content types in a many-way relationship. The field on the left content type links to many records in the right content type. The right content type does not link back to the left content type.

Via Strapi Project

Let's see how we set relations in our content types from our Strapi project. The content types in a Strapi project are stored in the ./src/api/ folder in our Strapi project. The relations are set in the ./src/api/[NAME]/content-types/[NAME]/schema.json file.

Fields are set inside the attributes section. To set a relation field we use some properties like model, collection, etc. Let's see how we set the relations for all the types of relations in Strapi.

One-to-One (1:1)

To set a one-to-one relation between two content types, we’ll create a new property in the attributes property. Let's say we want to set a one-to-one between a Student model and a Student-info model, we will open the ./src/api/student/content-types/student/schema.json file and add the code:

1    {
2      "kind": "collectionType",
3      "collectionName": "students",
4      "info": {
5        "singularName": "student",
6        "pluralName": "students",
7        "displayName": "Student",
8        "description": ""
9      },
10      "options": {
11        "draftAndPublish": true
12      },
13      "pluginOptions": {},
14    
15      // The fields are configured here
16      "attributes": {
17        "name": {
18          "type": "string"
19        },
20    
21        "student_info": { //field name
22          "type": "relation", // field type
23          "relation": "oneToOne", // relation type
24          "target": "api::student-info.student-info", // the target of the relation
25          "inversedBy": "student" // more info here - https://docs.strapi.io/developer-docs/latest/development/backend-customization/models.html#relations
26        }
27      }
28    }

The relation field is student_info. The model refers to the content type in Strapi the field is pointing to. It is set to student_info and so this property in the Student content type points to the student_info content type.

We set the type as relation and the relation as oneToOne. All these state that the Student model has and belongs to one StudentInfo.

Let's see inside ./src/api/student-info/content-types/student-info/schema.json file

1    {
2      "kind": "collectionType",
3      "collectionName": "student_infos",
4      "info": {
5        "singularName": "student-info",
6        "pluralName": "student-infos",
7        "displayName": "studentInfo"
8      },
9      "options": {
10        "draftAndPublish": true
11      },
12      "pluginOptions": {},
13      "attributes": {
14        "bio": {
15          "type": "text"
16        },
17        "student": {
18          "type": "relation",
19          "relation": "oneToOne",
20          "target": "api::student.student",
21          "inversedBy": "student_info"
22        }
23      }
24    }

Here, we have a student property which points to the student collection type. The relation set here is also oneToOne

These two JSON configs of both Student and StudentInfo models establish a one-to-one relationship between them as you can see in the interface below. This is similar for all other relations.

One-to-Many

Let's say we have two content types, Employee and Company. The Company has many Employee records, and the Employee record points back to a Company record. To establish this in the content types, we will go to their /schema.json files in our project and set relational fields in Strapi.

For the Company model, we want an employees relation to point to many Employees. So we will do the below in the ./src/api/company/content-types/company/schema.json file.

1    {
2    ...  
3    "attributes": {
4        "name": {
5          "type": "string"
6        },
7        "employees": {
8          "type": "relation",
9          "relation": "oneToMany",
10          "target": "api::employee.employee",
11          "mappedBy": "company"
12        }
13      }
14    }

Also, in ./src/api/employee/content-types/employee/schema.json file:

1    {
2    ...  
3      "attributes": {
4        "name": {
5          "type": "string"
6        },
7        "company": {
8          "type": "relation",
9          "relation": "manyToOne",
10          "target": "api::company.company",
11          "inversedBy": "employees"
12        }
13      }
14    }

This sets a one-to-many relationship in the Company model.

Many-to-Many

In setting a many-to-many relation from our Strapi project, we will set the relation field of both content types. For example, doctors can work in many hospitals and many hospitals can have many doctors. In this case, our Doctor model in ./src/api/doctor/content-types/doctor/schema.json will be this:

1    {
2      ...
3      "attributes": {
4        "name": {
5          "type": "string"
6        },
7        "hospitals": {
8          "type": "relation",
9          "relation": "manyToMany",
10          "target": "api::hospital.hospital",
11          "inversedBy": "doctors"
12        }
13      }
14    }

The hospital relation field points to many hospitals.

The Hospital model will be this: ./src/api/hospital/content-types/hospital/schema.json:

1    {
2      ...
3      "attributes": {
4        "name": {
5          "type": "string"
6        },
7        "doctors": {
8          "type": "relation",
9          "relation": "manyToMany",
10          "target": "api::doctor.doctor",
11          "inversedBy": "hospitals"
12        }
13      }
14    }

This effectively sets a many-to-many relation between the Doctor and Hospital models.

One-Way

To set this relation from our Strapi project between two models, we will define a relation field in one model's /schema.json file only. The other model will have no relation connecting to other model define in its /schema.json file.

For example, we have two models User and Detail and they have one-way relation. To set this up. We set the below in the User's model file user/models/user.settings.json file:

1    {
2      ...  
3      "attributes": {
4        "name": {
5          "type": "string"
6        },
7        "details": {
8          "type": "relation",
9          "relation": "oneToOne", 
10          "target": "api::detail.detail"
11        }
12      }
13    }

There will be no relation setting in the Detail schema file that will point to the User model. So in this way, we have set a one-way relation between the User and Detail models in Strapi.

Many-Way

This is the same as the one-way relation, but this one involves one model pointing to many records in another model, but this other model does not point back. To set this manually in Strapi, we will set a relation field with the collection property in one model but no relation definition in the other model.

For example, a User has many Cars. The relation is many-way. A user can own many cars. The setting will be this for the User: user/models/user.settings.json:

1    {
2      ...  
3      "attributes": {
4        "name": {
5          "type": "string"
6        },
7        "cars": {
8          "type": "relation",
9          "relation": "oneToMany",
10          "target": "api::car.car"
11        }
12      }
13    }

The car relation has a collection property that is set to car. This setting tells Strapi that the cars field in the User model points to many Car records. We will not make a relation in the Car model that will point back to the User model because this is a many-way relation.

We have learned all the relations in Strapi and also learned how to set them up both via the Strapi admin UI panel and from a Strapi project. Now, we show how to use some of the relations in Strapi to build a real-life app.

Setting up Strapi Project

We will create a Q&A app just like Quora, and users can ask questions, answer questions, and comment on answers. We will build this app to demonstrate how to use Strapi relations to link our models.

This project will be in two parts: the backend and the front-end. Of course, the backend will be built using Strapi, and the front-end will be built using Next.js.

We will create a central folder that will hold both backend and frontend projects:

mkdir relations

mkdir understanding-and-using-relations-in-strapi

We move into the folder:

cd relations

cd understanding-and-using-relations-in-strapi

Create the Strapi project:

npx create-strapi@latest

The CLI will ask a few more questions:

npx create-strapi@latest

 Strapi   v5.0.1 🚀 Let's create your new project

? What is the name of your project? qa-app
 
We can't find any auth credentials in your Strapi config.

Create a free account on Strapi Cloud and benefit from:

- ✦ Blazing-fast ✦ deployment for your projects
- ✦ Exclusive ✦ access to resources to make your project successful
- An ✦ Awesome ✦ community and full enjoyment of Strapi's ecosystem

Start your 14-day free trial now!


? Please log in or sign up. Skip
? Do you want to use the default database (sqlite) ? Yes
? Start with an example structure & data? No
? Start with Typescript? Yes
? Install dependencies with npm? Yes
? Initialize a git repository? Yes

 Strapi   Creating a new application at /Users/theodore/dev/qa-app

   deps   Installing dependencies with npm

The above command will create a Strapi project in qa-app folder inside the understanding-and-using-relations-in-strapi folder.

To start the project, run:

npm run develop

Strapi will serve the project on localhost:1337. It will launch the Strapi admin UI panel on localhost:1337/admin.

Fill in your details and click on the LET'S START button. We will begin to build our collections but first, let's draw our models.

Models

We will have three models for our Q&A app. We will have Question, Answer and Comment. Our Question model will be this:

1Question {
2    qText
3    user
4}

• qText: This will hold the question.
• user: This holds the name of the user.

The Answer model will be this:

1Answer {
2    aText
3    question
4    user
5}

• aText: This holds the answer text.
• question: This holds the reference to the question.
• user: The user that answered.

The Comment model will look like this:

1Comment {
2    cText
3    answer
4    user
5}

• cText: This will hold the comment text on the answer.
• answer: This is the reference to the answer.
• user: The user that commented.

We have seen how our collection will look like, now let's build our collections. These models have relationships that connect them. Let's see them below.

One-to-Many

The Question model and the Answer model have a one-to-many relationship. A Question will have many Answers. Now, we will build a Question collection in Strapi, and also we will create the Answer collection and there we will establish the relation between them. Now, on the http://localhost:1337/admin/ page click on the Create First Content Type button, a modal will appear. We will create the Question collection.

• Type question in the Display name field.
• Click on the text field.
• Type qText in the Name field.
• Select Long Text in the below radio button.

• Click on + Add another field.
• Select text.
• Type in user.

• Click on Finish.
• Next, click on the Save button on the top-right of the page.

Next, we will create the Answer collection

• Click on the + Create new collection type link, a modal will show up, type in answer. Click on the + Add another field button.
• Select text and type in aText.
• Select Long Text

• Click on + Add another field
• Select text and type in user.

• Select relation field.
• On the right box, press on the dropdown element and select Question.
• Click on the fourth small box, counting from left. The box establishes a one-to-many relationship between the Question collection and the Answer collection.

• Click on the Finish button.
• Next, click on the Save button on the top-right of the page.

One-to-One

The Comment model and the Answer model have a one-to-one relationship. A comment has one answer. We will create the Comment collection.

• Click on the + Create new collection type link, a modal will show up, type in comment.

• Click on the + Add another field button.
• Select text field.
• Type in cText and click on the + Add another field button.

• Select relation field.
• On the big box on the right, click on the dropdown element and select Answer.
• Select the first small box, counting from the left. This box establishes the one-to-one relationship between the Comment and the Answer but not from Answer to comment. So, the comments field will not appear on the Answer response.

• Click on the Finish button.
• Next, click on the Save button on the top-right of the page.

We are done building our collections and establishing their relationships. Now, let's build the front end.

Before we start building the frontend, we have set the permissions for a Public unauthenticated user so that our Strapi API can return data from routes without authentication.

NOTE: You’d typically need authentication in your application, especially when dealing with create, delete and update endpoints

Enable all permissions for answer collection type

Enable all permissions for question collection type

Enable all permissions for comment collection type

Building the QnA App

Our app will have two pages: the index and the question view page.

• / index: This page will display all questions in the app.
• /questions/:id: This page is a dynamic page. It will display the details of a specific question. The details displayed are the answers to the question and the comments are replies to the answers.

npx create-next-app@latest

Then we complete some prompts:

npx create-next-app@latest qa-front
Need to install the following packages:
create-next-app@14.2.8
Ok to proceed? (y) y

✔ Would you like to use TypeScript? … No / Yes
✔ Would you like to use ESLint? … No / Yes
✔ Would you like to use Tailwind CSS? … No / Yes
✔ Would you like to use `src/` directory? … No / Yes
✔ Would you like to use App Router? (recommended) … No / Yes
✔ Would you like to customize the default import alias (@/*)? … No / Yes
Creating a new Next.js app in /Users/miracleio/Documents/writing/strapi/understanding-and-using-relations-in-strapi/qa-front.

Using npm.

Initializing project with template: app-tw


Installing dependencies:
- react
- react-dom
- next

Installing devDependencies:
- typescript
- @types/node
- @types/react
- @types/react-dom
- postcss
- tailwindcss
- eslint
- eslint-config-next

npm warn deprecated inflight@1.0.6: This module is not supported, and leaks memory. Do not use it. Check out lru-cache if you want a good and tested way to coalesce async requests by a key value, which is much more comprehensive and powerful.
npm warn deprecated @humanwhocodes/config-array@0.11.14: Use @eslint/config-array instead
npm warn deprecated rimraf@3.0.2: Rimraf versions prior to v4 are no longer supported
npm warn deprecated @humanwhocodes/object-schema@2.0.3: Use @eslint/object-schema instead
npm warn deprecated glob@7.2.3: Glob versions prior to v9 are no longer supported

added 368 packages, and audited 369 packages in 56s

139 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities
Initialized a git repository.

Success!

Now, we move into the directory:

cd qa-front

We will need the following dependencies:

• axios: We will need this for making HTTP calls to our Strapi collection endpoints.
• quill: An editor we will use for answering questions in our app.

We will install axios:

yarn add axios

npm install quill axios react-quill

Setting up Shadcn/UI

To speed up developmemnt we'll be leveraging shadcn/ui which is a collection of re-usable components that you can copy and paste into your apps.

npx shadcn@latest init

You will be asked a few questions to configure components.json:

Which style would you like to use? › New York
Which color would you like to use as base color? › Zinc
Do you want to use CSS variables for colors? › no / yes

We can now start adding components to your project.

npx shadcn@latest add drawer button input label avatar textarea sonner

Complete the prompts:

npx shadcn@latest add drawer button input label avatar textarea
✔ You need to create a component.json file to add components. Proceed? … yes
✔ Which style would you like to use? › New York
? Which color would you like to use as the base color? › - Use arrow-keys. Return to submit.
? Which color would you like to use as the base color? › - Use arrow-keys. Return to submit.
? Which color would you like to use as the base color? › - Use arrow-keys. Return to submit.
? Which color would you like to use as the base color? › - Use arrow-keys. Return to submit.
? Which color would you like to use as the base color? › - Use arrow-keys. Return to submit.
✔ Which color would you like to use as the base color? › Slate
✔ Would you like to use CSS variables for theming? … no / yes
✔ Writing components.json.
✔ Checking registry.
✔ Installing dependencies.
✔ Created 7 files:
  - components/ui/drawer.tsx
  - components/ui/button.tsx
  - components/ui/input.tsx
  - components/ui/label.tsx
  - components/ui/avatar.tsx
  - components/ui/textarea.tsx
  - components/ui/sonner.tsx

Fetching Data

Let's create the utility functions and type definnitions that we need to interact with the Strapi API.

Strapi v5 changes

The Strapi v5 API response format has been refined a bit from v4. Noteably, there's no longer an attributes to nest the incoming data.

Strapi 5 now uses documents and documents are accessed by their documentId.

Here's a sample of the data:

1{
2  "data": [
3    {
4      "id": 2,
5      "documentId": "m2sdmnhihlkxolcvicrz4d4t",
6      "qText": "How does Vibranium compare to Stark tech in terms of strength and versatility?",
7      "user": "Happy Hogan",
8      "createdAt": "2024-09-09T16:46:40.624Z",
9      "updatedAt": "2024-09-09T16:46:40.624Z",
10      "publishedAt": "2024-09-09T16:46:41.040Z",
11      "locale": null
12    },
13    {
14      "id": 4,
15      "documentId": "a971959k5jbf7yqmxwgnrn02",
16      "qText": "Could Tony Stark’s AI, JARVIS, have evolved into something beyond just an assistant?",
17      "user": "Happy Hogan",
18      "createdAt": "2024-09-09T18:39:34.602Z",
19      "updatedAt": "2024-09-09T18:39:34.602Z",
20      "publishedAt": "2024-09-09T18:39:34.980Z",
21      "locale": null
22    }
23  ],
24  "meta": {
25    "pagination": {
26      "page": 1,
27      "pageSize": 25,
28      "pageCount": 1,
29      "total": 2
30    }
31  }
32}

Now, we'll create the types for our data response.

Creating Types

Create a new file ./types/index.ts:

mkdir types
touch types/index.ts

Enter the following:

1type Comment = {
2  id: number;
3  documentId: string;
4  cText: string;
5  createdAt: string;
6  updatedAt: string;
7  publishedAt: string;
8  locale: null;
9  user: string;
10  answer: Answer;
11};
12
13type CommentInput = {
14  cText: string;
15  user: string;
16  answer: string;
17};
18
19type Answer = {
20  id: number;
21  documentId: string;
22  aText: string;
23  user: string;
24  createdAt: string;
25  updatedAt: string;
26  publishedAt: string;
27  locale: null;
28  question?: Question | null;
29};
30
31type Question = {
32  id: number;
33  documentId: string;
34  qText: string;
35  user: string;
36  createdAt: string;
37  updatedAt: string;
38  publishedAt: string;
39  locale: null;
40  answers?: Answer[] | null;
41};
42
43type Meta = {
44  pagination: {
45    page: number;
46    pageSize: number;
47    pageCount: number;
48    total: number;
49  };
50};
51
52type AnswersResponse = {
53  data?: Answer[];
54  meta?: Meta;
55};
56
57type QuestionsResponse = {
58  data?: Question[];
59  meta?: Meta;
60};
61
62type CommentsResponse = {
63  data?: Comment[];
64  meta?: Meta;
65};
66
67type QuestionResponse = {
68  data?: Question;
69};
70
71type AnswerResponse = {
72  data?: Answer;
73};
74
75type CommentResponse = {
76  data?: Comment;
77};
78
79type ErrorResponse = {
80  error?: {
81    message: string;
82  };
83};
84
85export type {
86  Answer,
87  Question,
88  Comment,
89  CommentInput,
90  Meta,
91  QuestionsResponse,
92  QuestionResponse,
93  AnswersResponse,
94  AnswerResponse,
95  CommentsResponse,
96  CommentResponse,
97  ErrorResponse,
98};

With these types we can confidently fetch data from our API and use it within our application.

Create Data fetching functions

Next, we'll create data fetching functions to GET and POST data.

Create a new file ./utils/index.ts:

mkdir utils
touch utils/index.ts

Enter the following:

1// ./utils/index.ts
2
3import {
4  AnswerResponse,
5  AnswersResponse,
6  CommentInput,
7  CommentResponse,
8  CommentsResponse,
9  ErrorResponse,
10  QuestionResponse,
11  QuestionsResponse,
12} from "@/types";
13
14const API_TOKEN = process.env.NEXT_PUBLIC_API_TOKEN;
15const API_URL = process.env.NEXT_PUBLIC_API_URL;
16
17/**
18 * Fetches a list of questions from the API, sorted by their last update time in ascending order.
19 *
20 * @returns {Promise<QuestionsResponse & ErrorResponse>} - A promise that resolves with the list of questions and any errors encountered.
21 */
22const getQuestions: () => Promise<
23  QuestionsResponse & ErrorResponse
24> = async (): Promise<QuestionsResponse & ErrorResponse> => {
25  try {
26    const res = await fetch(`${API_URL}/questions?sort[0]=updatedAt:asc`, {
27      headers: {
28        Authorization: `Bearer ${API_TOKEN}`,
29      },
30      cache: "no-store",
31    });
32    const data = await res.json();
33    console.log("🚀 ~ getQuestions ~ data", data);
34
35    return data;
36  } catch (error) {
37    console.log("🚨 ~ getQuestions", error);
38    return {
39      error: { message: "Unable to fetch questions" },
40    };
41  }
42};
43
44/**
45 * Creates a new question in the API.
46 *
47 * @param {Object} question - The question data.
48 * @param {string} question.qText - The text of the question.
49 * @param {string} question.user - The user ID of the person asking the question.
50 * @returns {Promise<QuestionResponse & ErrorResponse>} - A promise that resolves with the created question and any errors encountered.
51 */
52const createQuestion = async (question: {
53  qText: string;
54  user: string;
55}): Promise<QuestionResponse & ErrorResponse> => {
56  console.log("🚀 ~ createQuestion ~ question", question);
57
58  try {
59    const res = await fetch(`${API_URL}/questions`, {
60      method: "POST",
61      headers: {
62        "Content-Type": "application/json",
63        Authorization: `Bearer ${API_TOKEN}`,
64      },
65      body: JSON.stringify({
66        data: {
67          qText: question.qText,
68          user: question.user,
69        },
70      }),
71    });
72    const data = await res.json();
73    return data;
74  } catch (error) {
75    console.log("🚨 ~ createQuestion", error);
76    return {
77      error: { message: "Unable to create question" },
78    };
79  }
80};
81
82/**
83 * Fetches comments related to a specific answer from the API, sorted by their last update time in ascending order.
84 *
85 * @param {string} answer - The ID of the answer to fetch comments for.
86 * @returns {Promise<CommentsResponse & ErrorResponse>} - A promise that resolves with the list of comments and any errors encountered.
87 */
88const getComments = async (
89  answer: string,
90): Promise<CommentsResponse & ErrorResponse> => {
91  try {
92    const res = await fetch(
93      `${API_URL}/comments?populate=*&filters[answer][documentId]=${answer}&sort[0]=updatedAt:asc`,
94      {
95        headers: {
96          Authorization: `Bearer ${API_TOKEN}`,
97        },
98        cache: "no-store",
99      },
100    );
101    const data = await res.json();
102    if (data.error) {
103      throw new Error(data.error.message);
104    }
105    return data;
106  } catch (error) {
107    console.log("🚨 ~ getComments", error);
108    return {
109      error: { message: "Unable to fetch comments" },
110    };
111  }
112};
113
114/**
115 * Creates a new comment in the API.
116 *
117 * @param {CommentInput} comment - The comment data.
118 * @returns {Promise<CommentResponse & ErrorResponse>} - A promise that resolves with the created comment and any errors encountered.
119 */
120const createComment: (
121  comment: CommentInput,
122) => Promise<CommentResponse & ErrorResponse> = async ({
123  cText,
124  user,
125  answer,
126}: CommentInput): Promise<CommentResponse & ErrorResponse> => {
127  try {
128    const res = await fetch(`${API_URL}/comments`, {
129      method: "POST",
130      headers: {
131        "Content-Type": "application/json",
132        Authorization: `Bearer ${API_TOKEN}`,
133      },
134      body: JSON.stringify({ data: { cText, user, answer } }),
135    });
136    const data = await res.json();
137    if (data.error) {
138      throw new Error(data.error.message);
139    }
140    return data;
141  } catch (error) {
142    console.log("🚨 ~ createComment", error);
143    return {
144      error: { message: "Unable to create comment" },
145    };
146  }
147};
148
149/**
150 * Creates a new answer in the API.
151 *
152 * @param {Object} answer - The answer data.
153 * @param {string} answer.aText - The text of the answer.
154 * @param {string} answer.user - The user ID of the person providing the answer.
155 * @param {string} answer.questionId - The ID of the question that the answer is related to.
156 * @returns {Promise<AnswerResponse & ErrorResponse>} - A promise that resolves with the created answer and any errors encountered.
157 */
158const createAnswer = async (answer: {
159  aText: string;
160  user: string;
161  questionId: string;
162}): Promise<AnswerResponse & ErrorResponse> => {
163  console.log("🚀 ~ createAnswer ~ answer", answer);
164
165  try {
166    const res = await fetch(`${API_URL}/answers`, {
167      method: "POST",
168      headers: {
169        "Content-Type": "application/json",
170        Authorization: `Bearer ${API_TOKEN}`,
171      },
172      body: JSON.stringify({
173        data: {
174          aText: answer.aText,
175          user: answer.user,
176          question: answer.questionId,
177        },
178      }),
179    });
180    const data = await res.json();
181    return data;
182  } catch (error) {
183    console.log("🚨 ~ createAnswer", error);
184    return {
185      error: { message: "Unable to create answer" },
186    };
187  }
188};
189
190/**
191 * Fetches a specific question from the API by its ID.
192 *
193 * @param {string} id - The ID of the question to fetch.
194 * @returns {Promise<QuestionResponse & ErrorResponse>} - A promise that resolves with the question data and any errors encountered.
195 */
196const getQuestion: (
197  id: string,
198) => Promise<QuestionResponse & ErrorResponse> = async (id: string) => {
199  try {
200    const res = await fetch(`${API_URL}/questions/${id}?populate=*`, {
201      headers: {
202        Authorization: `Bearer ${API_TOKEN}`,
203      },
204      cache: "no-store",
205    });
206    const data = await res.json();
207    if (data.error) {
208      throw new Error(data.error.message);
209    }
210    return data;
211  } catch (error) {
212    console.log("🚨 ~ getQuestion", error);
213    return {
214      error: { message: "Unable to fetch question" },
215    };
216  }
217};
218
219/**
220 * Fetches a list of answers related to a specific question from the API, sorted by their creation time in ascending order.
221 *
222 * @param {string} question - The ID of the question to fetch answers for.
223 * @returns {Promise<AnswersResponse & ErrorResponse>} - A promise that resolves with the list of answers and any errors encountered.
224 */
225const getAnswers: (
226  question: string,
227) => Promise<AnswersResponse & ErrorResponse> = async (
228  question: string,
229): Promise<AnswersResponse & ErrorResponse> => {
230  try {
231    const res = await fetch(
232      `${API_URL}/answers?populate=*&filters[question][documentId]=${question}&sort[0]=createdAt:asc`,
233      {
234        headers: {
235          Authorization: `Bearer ${API_TOKEN}`,
236        },
237        cache: "no-store",
238      },
239    );
240    const data = await res.json();
241    if (data.error) {
242      throw new Error(data.error.message);
243    }
244    return data;
245  } catch (error) {
246    console.log("🚨 ~ getAnswers", error);
247    return {
248      error: { message: "Unable to fetch answers" },
249    };
250  }
251};
252
253export {
254  getQuestion,
255  getQuestions,
256  createQuestion,
257  getAnswers,
258  createAnswer,
259  getComments,
260  createComment,
261};

This file defines several utility functions for interacting with an API that manages questions, answers, and comments. Here's a brief overview of each function:

1. getQuestions: Fetches a list of questions from the API, sorted by the updatedAt field in ascending order. The sort parameter is passed as a query string:

   1const res = await fetch(`${API_URL}/questions?sort[0]=updatedAt:asc`, {...});

   This ensures that the most recently updated questions are retrieved last.

2. createQuestion: Sends a POST request to create a new question. The question's text and user ID are included in the request body, which is sent as JSON.

   1body: JSON.stringify({ data: { qText: question.qText, user: question.user } }),

3. getComments: Fetches comments related to a specific answer, filtering by the answer's documentId and sorting by the updatedAt field in ascending order. The filter and sort parameters are included in the query string:

   1const res = await fetch(`${API_URL}/comments?populate=*&filters[answer][documentId]=${answer}&sort[0]=updatedAt:asc`, {...});

4. createComment: Sends a POST request to create a new comment. The comment's text, user ID, and related answer ID are included in the request body, similar to createQuestion.

5. createAnswer: Sends a POST request to create a new answer for a specific question. The answer's text, user ID, and the ID of the question it belongs to are included in the request body.

6. getQuestion: Fetches details for a specific question by its ID, using the populate=* query parameter to include related data:

   1const res = await fetch(`${API_URL}/questions/${id}?populate=*`, {...});

7. getAnswers: Fetches a list of answers related to a specific question, filtering by the question document ID and sorting by the createdAt field in ascending order:

   1const res = await fetch(`${API_URL}/answers?populate=*&filters[question][documentId]=${question}&sort[0]=createdAt:asc`, {...});

Each of these functions uses query parameters to filter and sort data returned by the API, ensuring that the correct data is retrieved in the desired order.

For example, the sort[0]=updatedAt:asc query parameter in getQuestions ensures that the list of questions is sorted by their update time, in ascending order. Similarly, the filters[answer][documentId]=${answer} parameter in getComments filters comments to only those related to a specific answer.

Note: The populate=* query parameter allows us to fetch all fields relation, media and components fields

Creating components

Now, we can create the components for displaying and posting data.

Question Card

Let's create a component for displaying questions - ./components/Question/Card.tsx and enter the following:

1// ./components/Question/Card.tsx
2
3import { Button } from "@/components/ui/button";
4import { Question } from "@/types";
5import Link from "next/link";
6
7const QuestionCard: React.FC<{
8  question: Question;
9}> = ({ question }) => {
10  return (
11    <article
12      key={question.id}
13      className="rounded-none border border-stone-100 bg-stone-50 p-4 dark:border-stone-700 dark:bg-stone-800"
14    >
15      <h3 className="text-3xl font-semibold">{question.qText}</h3>
16      <p className="text-stone-600 dark:text-stone-400">
17        Asked by {question.user} on{" "}
18        {new Date(question.createdAt).toDateString()}
19      </p>
20      <Button variant="outline" className="mt-3" asChild>
21        <Link href={`/questions/${question.documentId}`}>View Question</Link>
22      </Button>
23    </article>
24  );
25};
26
27export default QuestionCard;

This code defines a QuestionCard React component that displays a question's text, the user who asked it, and the date it was created. It includes a button that links to the detailed view of the question. The component uses Tailwind CSS classes for styling and receives a question object as a prop.

Question Form

Now, let's create the form component for creating new questions - ./components/Question/Form.tsxand enter the following:

1// ./components/Question/Form.tsx
2
3import { cn } from "@/lib/utils";
4import { Button } from "@/components/ui/button";
5import { Input } from "@/components/ui/input";
6import { Label } from "@/components/ui/label";
7import { Textarea } from "@/components/ui/textarea";
8import { toast } from "sonner";
9import { useState } from "react";
10import { useRouter } from "next/navigation";
11import { createQuestion } from "@/utils";
12
13const QuestionForm: React.FC<{
14  className?: string;
15}> = ({ className }) => {
16  const [question, setQuestion] = useState("");
17  const [name, setName] = useState("");
18  const [loading, setLoading] = useState(false);
19  const router = useRouter();
20
21  const handleSubmit = async (e: React.FormEvent<HTMLFormElement>) => {
22    e.preventDefault();
23    if (!question.trim() || !name.trim()) {
24      toast.error("Please fill in all fields");
25      return;
26    }
27    toast.promise(createQuestion({ qText: question, user: name }), {
28      loading: (() => {
29        setLoading(true);
30        return "Submitting question...";
31      })(),
32      success: (data) => {
33        console.log("🚀 ~ handleSubmit ~ data", data);
34
35        if (data.error) {
36          throw new Error(data.error.message);
37        }
38        setLoading(false);
39        setQuestion("");
40        setName("");
41        router.push(`/questions/${data.data?.documentId}`);
42
43        return "Question submitted successfully!";
44      },
45      error: (error) => {
46        setLoading(false);
47        console.log("🚨 ~ handleSubmit ~ error", error);
48
49        return "Failed to submit question";
50      },
51    });
52  };
53  return (
54    <form
55      onSubmit={handleSubmit}
56      className={cn("grid items-start gap-4", className)}
57    >
58      <div className="grid gap-2">
59        <Label htmlFor="name">Name</Label>
60        <Input
61          type="name"
62          id="name"
63          defaultValue="Happy Hogan"
64          onChange={(e) => setName(e.target.value)}
65          value={name}
66        />
67      </div>
68      <div className="grid gap-2">
69        <Label htmlFor="question">Your Question</Label>
70        <Textarea
71          id="question"
72          value={question}
73          onChange={(e) => setQuestion(e.target.value)}
74        />
75      </div>
76      <Button type="submit">
77        {loading ? "Submitting question..." : "Submit Question"}
78      </Button>
79    </form>
80  );
81};
82
83export default QuestionForm;

The QuestionForm component allows users to submit a question. Here's a breakdown of its functionality:

• It uses useState hooks to manage the state of the question, name, and loading fields.
• The handleSubmit function:
  • Prevents the default form action.
  • Validates input fields.
  • Uses toast.promise to display loading, success, and error messages during the createQuestion API call.
  • Resets the form and redirects the user to the newly created question's page using router.push if the submission is successful.

Question Drawer

The Question form will be displayed in a drawer when the user wants to ask a new question. Create a new file - ./components/Question/Drawer.tsx:

1// ./components/Question/Drawer.tsx
2
3"use client";
4
5import {
6  Drawer,
7  DrawerClose,
8  DrawerContent,
9  DrawerDescription,
10  DrawerFooter,
11  DrawerHeader,
12  DrawerTitle,
13  DrawerTrigger,
14} from "@/components/ui/drawer";
15import { Button } from "@/components/ui/button";
16import { useState } from "react";
17import QuestionForm from "@/components/Question/Form";
18
19const QuestionDrawer: React.FC = () => {
20  const [isOpen, setIsOpen] = useState(false);
21  return (
22    <Drawer open={isOpen} onOpenChange={setIsOpen}>
23      <DrawerTrigger asChild>
24        <Button variant="outline">Ask Question</Button>
25      </DrawerTrigger>
26      <DrawerContent>
27        <div className="wrapper mx-auto w-full max-w-3xl">
28          <DrawerHeader className="text-left">
29            <DrawerTitle>Ask Question</DrawerTitle>
30            <DrawerDescription>What would you like to ask?</DrawerDescription>
31          </DrawerHeader>
32          {/* Question Form */}
33          <QuestionForm className="px-4" />
34          <DrawerFooter className="pt-2">
35            <DrawerClose asChild>
36              <Button variant="outline">Cancel</Button>
37            </DrawerClose>
38          </DrawerFooter>
39        </div>
40      </DrawerContent>
41    </Drawer>
42  );
43};
44
45export default QuestionDrawer;

Next, we'll create the components for Answers.

Answer Card

Create a new file - ./components/Answer/Card.tsx and enter the following:

1// ./components/Answer/Card.tsx
2
3"use client";
4
5import { Answer, Comment } from "@/types";
6import { Avatar, AvatarFallback, AvatarImage } from "@/components/ui/avatar";
7import CommentForm from "@/components/Comment/Form";
8import { useState } from "react";
9import { Button } from "@/components/ui/button";
10import { toast } from "sonner";
11import CommentCard from "@/components/Comment/Card";
12import { getComments } from "@/utils";
13
14const AnswerCard: React.FC<{
15  answer: Answer;
16}> = ({ answer }) => {
17  const [showPostComment, setShowPostComment] = useState(false);
18  const [showComments, setShowComments] = useState(false);
19  const [comments, setComments] = useState<Comment[] | null>(null);
20  const [loading, setLoading] = useState(false);
21
22  const handleGetComments = async () => {
23    if (showComments) {
24      setShowComments(false);
25      return;
26    }
27    setLoading(true);
28    toast.promise(getComments(answer?.documentId), {
29      loading: (() => {
30        setLoading(true);
31        return "Fetching comments...";
32      })(),
33      success: (data) => {
34        if (data?.error) {
35          return data.error.message;
36        }
37        if (!data?.data?.length) {
38          return "No comments yet. Be the first!";
39        }
40        setComments(data?.data);
41        setLoading(false);
42        return "Comments fetched successfully";
43      },
44      error: (error) => {
45        setLoading(false);
46        console.log("🚨 ~ handleGetComments ~ error", error);
47        return "Unable to fetch comments";
48      },
49      finally: () => {
50        setLoading(false);
51        setShowComments(true);
52      },
53    });
54  };
55
56  return (
57    <article className="flex flex-col rounded-none border border-stone-100 bg-stone-50 dark:border-stone-900 dark:bg-stone-900">
58      <div className="user flex w-full items-center gap-2 border-b border-stone-200 p-4 dark:border-stone-800">
59        <Avatar>
60          <AvatarImage
61            src={`https://avatar.iran.liara.run/public/${Math.floor(
62              Math.random() * 10 + 1,
63            )}`}
64            alt={answer?.user}
65          />
66          <AvatarFallback>
67            {answer?.user
68              ?.split(" ")
69              .map((name) => name[0])
70              .join("")}
71          </AvatarFallback>
72        </Avatar>
73        <p className=" ">{answer?.user}</p> on{" "}
74        <p>{new Date(answer?.updatedAt).toDateString()}</p>
75      </div>
76      <div
77        className="p-4"
78        {...{
79          dangerouslySetInnerHTML: {
80            __html: answer?.aText,
81          },
82        }}
83      ></div>
84      <div className="flex flex-wrap gap-2 border-t border-stone-200 p-4 dark:border-stone-800">
85        {!showPostComment ? (
86          <Button
87            onClick={() => setShowPostComment(!showPostComment)}
88            variant={"outline"}
89          >
90            Post a comment
91          </Button>
92        ) : (
93          <div className="w-full">
94            <Button
95              onClick={() => setShowPostComment(!showPostComment)}
96              variant={"outline"}
97              className="mb-4"
98            >
99              Hide comment form
100            </Button>
101            <CommentForm answer={answer?.documentId} />
102          </div>
103        )}
104        <Button onClick={handleGetComments} variant={"outline"}>
105          {loading
106            ? "Fetching comments..."
107            : showComments
108              ? "Hide comments"
109              : "Show comments"}
110        </Button>
111      </div>
112      {showComments && (
113        <div className="border-t border-stone-200 dark:border-stone-800">
114          {comments?.length ? (
115            <ul className="flex flex-col gap-4">
116              {comments.map((comment, i) => (
117                <li
118                  key={comment?.documentId}
119                  className="border-t border-stone-200 first-of-type:border-t-0 dark:border-stone-800"
120                >
121                  <CommentCard comment={comment} i={i} />
122                </li>
123              ))}
124            </ul>
125          ) : (
126            <p className="p-4">No comments yet. Be the first!</p>
127          )}
128        </div>
129      )}
130    </article>
131  );
132};
133
134export default AnswerCard;

Here's how it works:

• State Management: It uses useState hooks to manage the visibility of the comment form (showPostComment), the visibility of comments (showComments), the list of comments (comments), and the loading state (loading).
• User Interface: The component renders an article element that displays the answer, along with the user who posted it and the date. It uses an Avatar component to show the user's avatar or initials.
• Comment Handling:
  • When the "Post a comment" button is clicked, it toggles the visibility of the CommentForm by updating showPostComment.
  • When the "Show comments" button is clicked, it triggers handleGetComments, which fetches comments using the getComments function and updates the comments state. It also manages the loading state and displays a toast notification based on the success or failure of the operation.
• Comment Display: If comments are fetched and showComments is true, the component renders a list of CommentCard components. If there are no comments, it displays a message encouraging the user to be the first to comment.