Showing posts with label NextJS. Show all posts
Showing posts with label NextJS. Show all posts

Saturday, 19 April 2025

Web Tutorial: The Easter Poem Generator (Part 2/2)

We actually already created functions for validating and submitting earlier, so let's fill them up now.

We start with the handleChecking() function. We first get name, value and checked from the target object of the e object. target will be the checkbox that is checked. So we have finalValue. If the checkbox is checked, then finalValue has the value value. If not, its value is an empty string.

src/app/page.js
const handleChecking = (e) => {
  const { name, value, checked } = e.target;
  var finalValue = (checked ? value : "");

};


Whatever the value of finalValue, it will be used in setFormData(). We use the spread operator to destructure formData, then add in a name-value pair using name and finalValue. If name already appears in formData, it will thus be overwritten by the value of finalValue.

src/app/page.js
const handleChecking = (e) => {
  const { name, value, checked } = e.target;
  var finalValue = (checked ? value : "");

  setFormData({
    ...formData,
    [name]: finalValue
  });

};


What we want to do is ensure that at least one checkbox is checked. So we'll test this. Declare tempFormData as a clone of formData by using stringify() and parse() methods. Modify tempFormData's property, pointed to by name, changing its value to finalValue.

src/app/page.js
const handleChecking = (e) => {
  const { name, value, checked } = e.target;
  var finalValue = (checked ? value : "");

  var tempFormData = JSON.stringify(formData);
  tempFormData = JSON.parse(tempFormData);
  tempFormData[name] = finalValue;


  setFormData({
    ...formData,
    [name]: finalValue
  });
};


Now we use an If block to check if all the string values are empty strings. If that's true, we reset the value of finalValue to value. This ensures that there is never  a situation where all the properties are empty strings.

src/app/page.js
const handleChecking = (e) => {
  const { name, value, checked } = e.target;
  var finalValue = (checked ? value : "");

  var tempFormData = JSON.stringify(formData);
  tempFormData = JSON.parse(tempFormData);
  tempFormData[name] = finalValue;

  if (tempFormData.symbol_bunny + tempFormData.symbol_chicks + tempFormData.symbol_cross + tempFormData.symbol_eggs + tempFormData.symbol_lillies === "") {
    finalValue = value;
  }


  setFormData({
    ...formData,
    [name]: finalValue
  });
};


Try it... you can select multiple options but you will find that you'll never be able to deselect all of the options.

That's it for validation! Now we want to handle submitting.

We first ensure that the form is not automatically submitted, by using the preventDefault() method. We want to implement our own submit logic. After that, we use setGeneration() to set a loading message.

src/app/page.js
const handleSubmit = async (e) => {
  e.preventDefault();
  setGeneration( { poem: "<h2>Pease wait...</h2>" } );

};


We'll add a div, styled using the CSS class poemContainer, with the generation object's poem property as content.

src/app/page.js
return (
  <div className={styles.generationContainer} >
    <form onSubmit={handleSubmit}>
      <h1>Generate an Easter Poem!</h1>
      <b>Include at least one of these elements</b>
      {
        Object.entries(formData).map(([key, value]) => (
        <label className={styles.label} key={key}>
          <input type="checkbox" name={key} value={key.replace("symbol_", "")} onChange={handleChecking} checked={ (value !== "") } />
           {key.replace("symbol_", "")}
           <Link href={ ("/" +key.replace("_", "/")) } target="_blank">►</Link>
          <br />
        </label>
      ))}    
      <button type="submit" className={styles.button}>Go!</button>
      <br style={{ clear:"both" }} />
    </form>
    <div className={styles.poemContainer} >{ generation.poem } </div>
  </div>
);


Here's poemContainer. Just a bit of alignment and layout. Nothing crazy.

src/app/page.module.css
.generationContainer form {
  width: 450px;
  padding: 10px;
  margin: 0 auto 0 auto;
  border-radius: 10px;
  border: 1px solid rgb(255, 100, 100);
}

.poemContainer {
  width: 450px;
  padding: 10px;
  margin: 0 auto 0 auto;
  text-align: center;
}


.label {
  display: inline-block;
  width: 45%;
  float: left;
}


Now try Clicking the SUBMIT button. Looks like the HTML is being treated like text content!


We will rectify this using dangerouslySetInnerHTML. This renders raw HTML in a React component.

src/app/page.js
<div className={styles.poemContainer} dangerouslySetInnerHTML={{ __html: generation.poem }} />


This time, the loading message is properly formatted.



Now that this is done, we're going to make a call to the backend using fetch(). We'll pair it with await because its very nature is async. The endpoint is poemgen and we will be creating it after this. The result of the call to the backend will be assigned to the object response.

src/app/page.js
const handleSubmit = async (e) => {
  e.preventDefault();
  setGeneration( { poem: "<h2>Pease wait...</h2>" } );

  const response = await fetch("/api/poemgen", {

  });

};


In fetch(), the second argument is an object. It contains the method of the call (in this case, it's a POST), the headers object (which in this context basically tells fetch() that we're ending data in JSON format, and the body property. The last one contains formData as a JSON-formatted string.

src/app/page.js
const handleSubmit = async (e) => {
  e.preventDefault();
  setGeneration( { poem: "<h2>Pease wait...</h2>" } );

  const response = await fetch("/api/poemgen", {
    method: "POST",
    headers: {
      "Content-Type": "application/json"
    },
    body: JSON.stringify(formData)

  });
};


We then declare result and use it to store the value of response as a JSON object. Since the method we're using, json(), is asynchronous, we have to use await.

src/app/page.js
const handleSubmit = async (e) => {
  e.preventDefault();
  setGeneration( { poem: "<h2>Pease wait...</h2>" } );

  const response = await fetch("/api/poemgen", {
    method: "POST",
    headers: {
      "Content-Type": "application/json"
    },
    body: JSON.stringify(formData)
  });
  const result = await response.json();

};


We then check if status is 200. If so, we run setGeneration() and set the value of the poem property to the message property of result. If not, we handle the error by logging it in the console.

src/app/page.js
const handleSubmit = async (e) => {
  e.preventDefault();
  setGeneration( { poem: "<h2>Pease wait...</h2>" } );

  const response = await fetch("/api/poemgen", {
    method: "POST",
    headers: {
      "Content-Type": "application/json"
    },
    body: JSON.stringify(formData)
  });
  const result = await response.json();

  if (response.status === 200) {
    setGeneration( { poem: result.message } );
  } else {
    console.log(result);
  }

};


Now, in the app directory, create the api subdirectory, and in it, the poemgen subdirectory. In that, create route.js. This is the NextJS App router method of creating backend API endpoints. In this file, we export an async function that responds to the POST method. There is a parameter, req, that represents the request.

src/app/api/poemgen/route.js
export async function POST(req) {

}


We declare formData and use await to obtain the JSON object req. Then we declare symbols as an empty string.

src/app/api/poemgen/route.js
export async function POST(req) {
  const formData = await req.json();

  var symbols = "";
}


This is followed by a series of If blocks that correspond to each property in formData. If the value is not an empty string, concatenate that value to symbols, with a comma and space. Remember, there will never be a case where all the strings are empty. Thus, there will always be at least one comma and space. We remove the one at the end using the slice() method.

src/app/api/poemgen/route.js
export async function POST(req) {
  const formData = await req.json();

  var symbols = "";
  if (formData.symbol_bunny !== "") symbols += (formData.symbol_bunny + ", ");
  if (formData.symbol_chicks !== "") symbols += (formData.symbol_chicks + ", ");
  if (formData.symbol_cross !== "") symbols += (formData.symbol_cross + ", ");
  if (formData.symbol_eggs !== "") symbols += (formData.symbol_eggs + ", ");
  if (formData.symbol_lillies !== "") symbols += (formData.symbol_lillies + ", ");
  symbols = symbols.slice(0, -2);

}


Next, we declare headers as an object, and populate it with standard properties such as Authorization and Content-Type. Since this is for ChatGPT, we'll need OpenAI-Oganization also. Authorization and OpenAI-Oganization will have values that can be accessed from your .env file.

src/app/api/poemgen/route.js
export async function POST(req) {
  const formData = await req.json();

  var symbols = "";
  if (formData.symbol_bunny !== "") symbols += (formData.symbol_bunny + ", ");
  if (formData.symbol_chicks !== "") symbols += (formData.symbol_chicks + ", ");
  if (formData.symbol_cross !== "") symbols += (formData.symbol_cross + ", ");
  if (formData.symbol_eggs !== "") symbols += (formData.symbol_eggs + ", ");
  if (formData.symbol_lillies !== "") symbols += (formData.symbol_lillies + ", ");
  symbols = symbols.slice(0, -2);

  var headers = {
     "Authorization": "Bearer " + process.env.NEXT_PUBLIC_API_KEY,
     "OpenAI-Oganization": process.env.NEXT_PUBLIC_ORG,
     "Content-Type": "application/json"    
  };  

}


The values will look like this in the .env file. They won't, of course, be "xxx".

.env
NEXT_PUBLIC_API_KEY=xxx
NEXT_PUBLIC_ORG=org-xxx


Now create an empty array, messages. Then create an object, obj. It should have the property role, which has a value of "user", and the property content. Its value should be a prompt we create from symbols. After that, push obj into messages.

src/app/api/poemgen/route.js
export async function POST(req) {
  const formData = await req.json();

  var symbols = "";
  if (formData.symbol_bunny !== "") symbols += (formData.symbol_bunny + ", ");
  if (formData.symbol_chicks !== "") symbols += (formData.symbol_chicks + ", ");
  if (formData.symbol_cross !== "") symbols += (formData.symbol_cross + ", ");
  if (formData.symbol_eggs !== "") symbols += (formData.symbol_eggs + ", ");
  if (formData.symbol_lillies !== "") symbols += (formData.symbol_lillies + ", ");
  symbols = symbols.slice(0, -2);

  var headers = {
    "Authorization": "Bearer " + process.env.NEXT_PUBLIC_API_KEY,
    "OpenAI-Oganization": process.env.NEXT_PUBLIC_ORG,
    "Content-Type": "application/json"    
  };  

  var messages = [];
  var obj = {
    "role": "user",
    "content" : "Generate an Easter-themed poem with the following element(s): " + symbols + "."
  };
  messages.push(obj);

}


Create body as an object. In there, we specify the AI model and set the number of tokens to be used, to 2000. The messages property value will be the array messages.

src/app/api/poemgen/route.js
export async function POST(req) {
  const formData = await req.json();

  var symbols = "";
  if (formData.symbol_bunny !== "") symbols += (formData.symbol_bunny + ", ");
  if (formData.symbol_chicks !== "") symbols += (formData.symbol_chicks + ", ");
  if (formData.symbol_cross !== "") symbols += (formData.symbol_cross + ", ");
  if (formData.symbol_eggs !== "") symbols += (formData.symbol_eggs + ", ");
  if (formData.symbol_lillies !== "") symbols += (formData.symbol_lillies + ", ");
  symbols = symbols.slice(0, -2);

  var headers = {
    "Authorization": "Bearer " + process.env.NEXT_PUBLIC_API_KEY,
    "OpenAI-Oganization": process.env.NEXT_PUBLIC_ORG,
    "Content-Type": "application/json"    
  };  

  var messages = [];
  var obj = {
    "role": "user",
    "content" : "Generate an Easter-themed poem with the following element(s): " + symbols + "."
  };
  messages.push(obj);

  var body = {
     "model": "gpt-3.5-turbo",
     "messages" : messages,
     "max_tokens" : 2000
  };

}


Here, we have a Try-catch block. In here, we use fetch() to grab data via a REST endpoint provided by OpenAI, sending header and body as the data. The response is assigned to the variable apiResponse.

src/app/api/poemgen/route.js
export async function POST(req) {
  const formData = await req.json();

  var symbols = "";
  if (formData.symbol_bunny !== "") symbols += (formData.symbol_bunny + ", ");
  if (formData.symbol_chicks !== "") symbols += (formData.symbol_chicks + ", ");
  if (formData.symbol_cross !== "") symbols += (formData.symbol_cross + ", ");
  if (formData.symbol_eggs !== "") symbols += (formData.symbol_eggs + ", ");
  if (formData.symbol_lillies !== "") symbols += (formData.symbol_lillies + ", ");
  symbols = symbols.slice(0, -2);

  var headers = {
    "Authorization": "Bearer " + process.env.NEXT_PUBLIC_API_KEY,
    "OpenAI-Oganization": process.env.NEXT_PUBLIC_ORG,
    "Content-Type": "application/json"    
  };  

  var messages = [];
  var obj = {
    "role": "user",
    "content" : "Generate an Easter-themed poem with the following element(s): " + symbols + "."
  };
  messages.push(obj);

  var body = {
     "model": "gpt-3.5-turbo",
     "messages" : messages,
    "max_tokens" : 2000
  };

  try {
    const apiResponse = await fetch("https://api.openai.com/v1/chat/completions", {
         method: "POST",
         headers: headers,
         body: JSON.stringify(body)
     });
  } catch (error) {

  }

}


We then check the ok property of apiResponse. If this is false, we return a Response object with an appropriate status. We return the same thing if there is an exception thrown.

src/app/api/poemgen/route.js
export async function POST(req) {
  const formData = await req.json();

  var symbols = "";
  if (formData.symbol_bunny !== "") symbols += (formData.symbol_bunny + ", ");
  if (formData.symbol_chicks !== "") symbols += (formData.symbol_chicks + ", ");
  if (formData.symbol_cross !== "") symbols += (formData.symbol_cross + ", ");
  if (formData.symbol_eggs !== "") symbols += (formData.symbol_eggs + ", ");
  if (formData.symbol_lillies !== "") symbols += (formData.symbol_lillies + ", ");
  symbols = symbols.slice(0, -2);

  var headers = {
    "Authorization": "Bearer " + process.env.NEXT_PUBLIC_API_KEY,
    "OpenAI-Oganization": process.env.NEXT_PUBLIC_ORG,
    "Content-Type": "application/json"    
  };  

  var messages = [];
  var obj = {
    "role": "user",
     "content" : "Generate an Easter-themed poem with the following element(s): " + symbols + "."
  };
  messages.push(obj);

  var body = {
     "model": "gpt-3.5-turbo",
     "messages" : messages,
     "max_tokens" : 2000
  };

  try {
    const apiResponse = await fetch("https://api.openai.com/v1/chat/completions", {
         method: "POST",
         headers: headers,
         body: JSON.stringify(body)
     });

    if (!apiResponse.ok) {
      return new Response(JSON.stringify({ message: "Error in poem generation" }), {
        status: 500,
        headers: { "Content-Type": "application/json" },
       });
     }

  } catch (error) {
     return new Response(JSON.stringify({ message: error.message }), {
      status: 500,
      headers: { "Content-Type": "application/json" },
    });

  }
}


Here, we obtain data by converting apiResponse to JSON using the asynchronous method json(). And we'll define html_content as the generated content but with HTML breaks in place of line breaks.

src/app/api/poemgen/route.js
export async function POST(req) {
  const formData = await req.json();

  var symbols = "";
  if (formData.symbol_bunny !== "") symbols += (formData.symbol_bunny + ", ");
  if (formData.symbol_chicks !== "") symbols += (formData.symbol_chicks + ", ");
  if (formData.symbol_cross !== "") symbols += (formData.symbol_cross + ", ");
  if (formData.symbol_eggs !== "") symbols += (formData.symbol_eggs + ", ");
  if (formData.symbol_lillies !== "") symbols += (formData.symbol_lillies + ", ");
  symbols = symbols.slice(0, -2);

  var headers = {
    "Authorization": "Bearer " + process.env.NEXT_PUBLIC_API_KEY,
     "OpenAI-Oganization": process.env.NEXT_PUBLIC_ORG,
     "Content-Type": "application/json"    
  };  

  var messages = [];
  var obj = {
     "role": "user",
     "content" : "Generate an Easter-themed poem with the following element(s): " + symbols + "."
  };
  messages.push(obj);

  var body = {
    "model": "gpt-3.5-turbo",
     "messages" : messages,
     "max_tokens" : 2000
  };

  try {
      const apiResponse = await fetch("https://api.openai.com/v1/chat/completions", {
           method: "POST",
           headers: headers,
           body: JSON.stringify(body)
       });

       if (!apiResponse.ok) {
        return new Response(JSON.stringify({ message: "Error in poem generation" }), {
          status: 500,
          headers: { "Content-Type": "application/json" },
      });
    }

    const data = await apiResponse.json();
    var html_content =  data.choices[0].message.content.replaceAll("\n", "<br />");

  } catch (error) {
    return new Response(JSON.stringify({ message: error.message }), {
        status: 500,
        headers: { "Content-Type": "application/json" },
    });
  }
}


And once that is done, we will return a new Response with the status 200 and html_content as the message.

src/app/api/poemgen/route.js
export async function POST(req) {
  const formData = await req.json();

  var symbols = "";
  if (formData.symbol_bunny !== "") symbols += (formData.symbol_bunny + ", ");
  if (formData.symbol_chicks !== "") symbols += (formData.symbol_chicks + ", ");
  if (formData.symbol_cross !== "") symbols += (formData.symbol_cross + ", ");
  if (formData.symbol_eggs !== "") symbols += (formData.symbol_eggs + ", ");
  if (formData.symbol_lillies !== "") symbols += (formData.symbol_lillies + ", ");
  symbols = symbols.slice(0, -2);

  var headers = {
     "Authorization": "Bearer " + process.env.NEXT_PUBLIC_API_KEY,
     "OpenAI-Oganization": process.env.NEXT_PUBLIC_ORG,
     "Content-Type": "application/json"    
  };  

  var messages = [];
  var obj = {
     "role": "user",
     "content" : "Generate an Easter-themed poem with the following element(s): " + symbols + "."
  };
  messages.push(obj);

  var body = {
     "model": "gpt-3.5-turbo",
    "messages" : messages,
    "max_tokens" : 2000
  };

  try {
    const apiResponse = await fetch("https://api.openai.com/v1/chat/completions", {
        method: "POST",
        headers: headers,
        body: JSON.stringify(body)
    });

    if (!apiResponse.ok) {
       return new Response(JSON.stringify({ message: "Error in poem generation" }), {
          status: 500,
          headers: { "Content-Type": "application/json" },
      });
    }

    const data = await apiResponse.json();
    var html_content =  data.choices[0].message.content.replaceAll("\n", "<br />");

    return new Response(JSON.stringify({ message: html_content }), {
      status: 200,
      headers: { "Content-Type": "application/json" },
    });

  } catch (error) {
     return new Response(JSON.stringify({ message: error.message }), {
       status: 500,
       headers: { "Content-Type": "application/json" },
     });
  }
}


Now try this! First, try it with one item checked.


Then try it with multiple items checked, and see the difference!


Enjoy your Easter!

This has been my virgin NextJS tutorial. We covered a fair amount of territory, and hopefully had fun in the process!

May your Easter eggs all be found,
His Teochewness will see you around!
T___T

Wednesday, 16 April 2025

Web Tutorial: The Easter Poem Generator (Part 1/2)

As of early 2025, the create-react-app method of ReactJS development was officially deprecated. As such, an alternative way forward was to use the ReactJS framework, NextJS. For today's Easter-themed web tutorial, I will be walking through some basic features of NextJS.

Do note that not a lot of things will be new here; the bulk of it is still doable in a standard ReactJS setup, or even NodeJS.

To begin, I will assume that NextJS has been installed on your machine. We'll create the app with this command. "easter-poem-generator" is the name of the app, and consequently, the folder that it will be created in.
npx create-next-app@latest easter-poem-generator


The script will ask some questions. These are the options I have chosen.
Would you like to use TypeScript?  No
Would you like to use ESLint?  No
Would you like to use Tailwind CSS?  No
Would you like your code inside a `src/` directory?  Yes
Would you like to use App Router? (recommended)  Yes
Would you like to use Turbopack for `next dev`?  No
Would you like to customize the import alias (`@/*` by default)?  No

Once done, navigate to the src folder. We'll make some changes to the layout.

src/app/layout.js
import { Geist, Geist_Mono } from "next/font/google";
import "./globals.css";

const geistSans = Geist({
  variable: "--font-geist-sans",
  subsets: ["latin"],
});

const geistMono = Geist_Mono({
  variable: "--font-geist-mono",
  subsets: ["latin"],
});

export const metadata = {
  title: "Easter Poem Generator",
  description: "Generated by create next app",
};

export default function RootLayout({ children }) {
  return (
    <html lang="en">
      <body className={`${geistSans.variable} ${geistMono.variable}`}>
        {children}
      </body>
    </html>
  );
}


Next, in the public directory, add these images.

public/symbol_bunny.jpg

public/symbol_chicks.jpg

public/symbol_cross.jpg

public/symbol_eggs.jpg

public/symbol_lillies.jpg

Time to create the form. We start with "use client" to state that this file is only for front-end JavaScript. Since JavaScript is being used for both front and back ends of the application, it's important to specify because this determines what features of JavaScript you'll get to use in the file.

src/app/page.js
"use client"


Then, because we have links in this page, we'll import the Link component. We will also import styles that have already been compiled. Finally, we will import useState because we will be using state variables.

src/app/page.js
"use client"

import Link from "next/link";
import styles from "./page.module.css";

import { useState } from "react";


Next, we create a main function for this page. We will create the return statement in advance.

src/app/page.js
"use client"

import Link from "next/link";
import styles from "./page.module.css";

import { useState } from "react";

export default function Home() {
  return (

  );
}


Now, if you know ReactJS at all, this should be familiar ground. This is why we imported useState earlier, so we can set state variables. The first thing we want is form data. Thus, formData will be an object containing these properties. As  default, only symbol_bunny is not an empty string.

src/app/page.js
export default function Home() {
  const [formData, setFormData] = useState({
    symbol_bunny: "bunny",
    symbol_chicks: "",
    symbol_cross: "",
    symbol_eggs: "",
    symbol_lillies: ""
  });


  return (

  );
}


And then we have generation, which is an object containing the property poem.

src/app/page.js
export default function Home() {
  const [formData, setFormData] = useState({
    symbol_bunny: "bunny",
    symbol_chicks: "",
    symbol_cross: "",
    symbol_eggs: "",
    symbol_lillies: ""
  });

  const [generation, setGeneration] = useState({
    poem: ""
  });


  return (

  );
}


Next, we have two functions. handleChecking() is something standar that happens instantaneously, to ensure that the input is correct. handleSubmit() is an asynchronous function because we are going to have to call API endpoints and wait for responses in this function.

src/app/page.js
const [formData, setFormData] = useState({
  symbol_bunny: "bunny",
  symbol_chicks: "",
  symbol_cross: "",
  symbol_eggs: "",
  symbol_lillies: ""
});

const [generation, setGeneration] = useState({
  poem: ""
});

const handleChecking = (e) => {

};

const handleSubmit = async (e) => {

};


return (

);


In the return statement there will be JSX. In here, we have a div styled using the CSS class generationContainer, and a form. The form will run handleSubmit() when data is submitted.

src/app/page.js
return (
  <div className={styles.generationContainer} >
    <form onSubmit={handleSubmit}>
      <h1>Generate an Easter Poem!</h1>
    </form>
  </div>

);


Clear out this file. We will add in the generationContainer CSS class. It's basically a centered div with a fixed width. Then we'll style the form. It has rounded corners and a solid light red border.

src/app/page.module.css
.generationContainer {
  width: 500px;
  margin: 0 auto 0 auto;
}

.generationContainer form {
  width: 450px;
  padding: 10px;
  margin: 0 auto 0 auto;
  border-radius: 10px;
  border: 1px solid rgb(255, 100, 100);
}


Not much to look at right now, but this will change soon.


We then have a line of instructions, and we will display a series of checkboxes based on the formData object. For this, we use the map() method on formData. Since formData is an object, we need to make it iterable by using the entries() method of Object, on it. entries() will turn formData into an array of objects containing properties and values.

src/app/page.js
return (
  <div className={styles.generationContainer} >
    <form onSubmit={handleSubmit}>
      <h1>Generate an Easter Poem!</h1>
      <b>Include at least one of these elements</b>
      {
        Object.entries(formData).map(([key, value]) => (

      ))}    

    </form>
  </div>
);


In this, we have a label tag styled using CSS class label. Because the ReactJS engine will complain if we don't, use key to populate the value of the key attribute.

src/app/page.js
return (
  <div className={styles.generationContainer} >
    <form onSubmit={handleSubmit}>
      <h1>Generate an Easter Poem!</h1>
      <b>Include at least one of these elements</b>
      {
        Object.entries(formData).map(([key, value]) => (
        <label className={styles.label} key={key}>

        </label>

      ))}    
    </form>
  </div>
);


We will then have a checkbox within that label tag. The name attribute will be key. handleChecking() will be run for the onchange() attribute. The checked value will depend if value is an empty string.

src/app/page.js
return (
  <div className={styles.generationContainer} >
    <form onSubmit={handleSubmit}>
      <h1>Generate an Easter Poem!</h1>
      <b>Include at least one of these elements</b>
      {
        Object.entries(formData).map(([key, value]) => (
        <label className={styles.label} key={key}>
          <input type="checkbox" name={key} value={key.replace("symbol_", "")} onChange={handleChecking} checked={ (value !== "") } />
          <br />
        </label>
      ))}    
    </form>
  </div>
);


Then add the text label key, again less the string "symbol_".

src/app/page.js
return (
  <div className={styles.generationContainer} >
    <form onSubmit={handleSubmit}>
      <h1>Generate an Easter Poem!</h1>
      <b>Include at least one of these elements</b>
      {
        Object.entries(formData).map(([key, value]) => (
        <label className={styles.label} key={key}>
          <input type="checkbox" name={key} value={key.replace("symbol_", "")} onChange={handleChecking} checked={ (formData[key] === key.replace("symbol_", "")) } />
           {key.replace("symbol_", "")}
          <br />
        </label>
      ))}    
    </form>
  </div>
);


Back to styles, label has a width that will take up less than half of its container, and be floated left.

src/app/page.module.css
.generationContainer form {
  width: 450px;
  padding: 10px;
  margin: 0 auto 0 auto;
  border-radius: 10px;
  border: 1px solid rgb(255, 100, 100);
}

.label {
  display: inline-block;
  width: 45%;
  float: left;
}


This is nothing that a CSS break won't fix.


Add this CSS break after adding a SUBMIT button.

src/app/page.js
return (
  <div className={styles.generationContainer} >
    <form onSubmit={handleSubmit}>
      <h1>Generate an Easter Poem!</h1>
      <b>Include at least one of these elements</b>
      {
        Object.entries(formData).map(([key, value]) => (
        <label className={styles.label} key={key}>
          <input type="checkbox" name={key} value={key.replace("symbol_", "")} onChange={handleChecking} checked={ (formData[key] === key.replace("symbol_", "")) } />
           {key.replace("symbol_", "")}
          <br />
        </label>
      ))}    
      <button type="submit" className={styles.button}>Go!</button>
      <br style={{ clear:"both" }} />

    </form>
  </div>
);


Just some styling for the button.

src/app/page.module.css
.generationContainer form {
  width: 450px;
  padding: 10px;
  margin: 0 auto 0 auto;
  border-radius: 10px;
  border: 1px solid rgb(255, 100, 100);
}

.label {
  display: inline-block;
  width: 45%;
  float: left;
}

.button {
  display: inline-block;
  width: 5em;
  height: 2em;
  float: right;
}


All falling into place nicely.


OK, we'll now add a Link component. Each link's route will be symbol followed by the identifier such as "bunny" or "eggs", thus I cleverly just took key and replaced the underscore with a forward slash.

src/app/page.js
return (
  <div className={styles.generationContainer} >
    <form onSubmit={handleSubmit}>
      <h1>Generate an Easter Poem!</h1>
      <b>Include at least one of these elements</b>
      {
        Object.entries(formData).map(([key, value]) => (
        <label className={styles.label} key={key}>
          <input type="checkbox" name={key} value={key.replace("symbol_", "")} onChange={handleChecking} checked={ (formData[key] === key.replace("symbol_", "")) } />
           {key.replace("symbol_", "")}
           <Link href={ ("/" +key.replace("_", "/")) } target="_blank">&#9658;</Link>
          <br />
        </label>
      ))}    
      <button type="submit" className={styles.button}>Go!</button>
      <br style={{ clear:"both" }} />
    </form>
  </div>
);


In order for the link to work, the route needs to work. So create the symbol directory in app. And in that directory, create the [symbolName] directory, square brackets and all. This tells NextJS that symbolName is a parameter value rather than an actual fixed value. And in that directory, create page.js. We'll want to import Image because we'll be working with images. As in the previous page we were working on, we want to import the CSS.

src/app/symbol/[symbolName]/page.js
import Image from "next/image";
import styles from "../../page.module.css";


We'll want to export this function. As always, we add a return statement inside the function.

src/app/symbol/[symbolName]/page.js
import Image from "next/image";
import styles from "../../page.module.css";

export default function SymbolPage({ params }) {
  return (

  );
}


params will contain symbolName, which will typically be "bunny", "lillies", etc. Thankfully, we've already saved those in the public directory, so they're accessible with just a slash. They can thus be used as the value of the src attribute for the Image component. Here, I have included the width and height of the image. The Image component will be placed inside a div styled using the symbolImage CSS class.

src/app/symbol/[symbolName]/page.js
export default function SymbolPage({ params }) {
  return (
    <div className={ styles.symbolImage } >
        <Image src={ "/symbol_" + params.symbolName + ".jpg" } alt={ params.symbolName } width={ 300 } height={ 300 } />
    </div>

  );
}


I am using symbolImage mostly for positioning. I have also set it so that any img tag inside symbolImage will have rounded corners.

src/app/page.module.css
.symbolImage {
  width: 100%;
  min-height: auto;
  margin: 10px auto 10px auto;
  text-align: center;
}

.symbolImage img{
  border-radius: 10px;
}


.generationContainer {
  width: 500px;
  margin: 0 auto 0 auto;
}


You can see the arrows. Now click on maybe the one beside "bunny".


You see a picture, in a new tab, with rounded corners!


We now add an object, texts. It has properties that mirror the possible values of symbolName.

src/app/symbol/[symbolName]/page.js
import Image from "next/image";
import styles from "../../page.module.css";

export default function SymbolPage({ params }) {
  const texts = {
   "bunny": ,
   "chicks": ,
   "cross": ,
   "eggs": ,
   "lillies":
  };


  return (
    <div className={ styles.symbolImage } >
        <Image src={ "/symbol_" + params.symbolName + ".jpg" } alt={ params.symbolName } width={ 300 } height={ 300 } />
    </div>
  );
}


Here, I'm going to add text strings as values for these properties. These were generated using Copilot.

src/app/symbol/[symbolName]/page.js
import Image from "next/image";
import styles from "../../page.module.css";

export default function SymbolPage({ params }) {
  const texts = {
   "bunny": "The bunny, or Easter rabbit, is a symbol of fertility and new life, which aligns with the themes of rebirth and renewal celebrated during Easter. Originating from ancient pagan traditions, the rabbit was associated with the goddess Ä’ostre, who represented spring and fertility. As Christianity spread, the symbolism of the rabbit was incorporated into Easter celebrations. The Easter bunny is often depicted delivering eggs, which are also symbols of new life and rebirth, to children, adding a playful and joyful element to the holiday.",
   "chicks": "Chicks are another symbol of new life and rebirth, aligning with the overall themes of Easter. Just as chicks hatch from eggs, they represent the idea of life emerging from the seemingly lifeless, echoing the resurrection of Jesus. They also symbolize innocence and the start of new beginnings, adding to the joyful and hopeful atmosphere of Easter celebrations. The imagery of chicks, along with eggs and bunnies, helps to convey the sense of renewal and the promise of new life that Easter embodies.",
   "cross": "The crucifix is a powerful symbol in Christianity, especially during Easter. It represents the crucifixion of Jesus Christ, an event central to Christian belief. It signifies the ultimate sacrifice Jesus made by dying on the cross to atone for humanity's sins. It also symbolizes the immense suffering Jesus endured during the crucifixion. The crucifix serves as a reminder of the redemption and salvation offered through Jesus' sacrifice. Easter celebrates Jesus' resurrection, signifying victory over death and the promise of eternal life for believers. This powerful imagery serves as a reminder of Jesus' love and the hope that comes with his resurrection, making the crucifix an integral part of Easter celebrations.",
   "eggs": "Eggs are a rich and multifaceted symbol in Easter traditions. They embody the themes of new life, rebirth, and resurrection, which are central to the celebration of Easter. They represent the emergence of new life from within, mirroring the resurrection of Jesus from the tomb. Just as a chick hatches from an egg, the concept of rebirth is symbolized, signifying the idea of starting anew. Historically, eggs have been seen as symbols of fertility and renewal, aligning with the arrival of spring. The egg, appearing lifeless on the outside but containing life within, represents transformation and the miracle of life. Eggs are often decorated and used in Easter egg hunts, making them a playful and engaging way to celebrate the holiday while reflecting on its deeper meanings.",
   "lillies": "Lilies, particularly white lilies, hold significant symbolism in Easter celebrations. They represent purity, virtue, and the resurrection of Jesus Christ. The trumpet shape of the lily flower is said to symbolize the trumpet call of God, heralding the resurrection. Lilies are often used in Easter decorations and church services to convey a sense of hope, renewal, and new beginnings. Their association with new life and purity makes them a fitting symbol for the themes of Easter."
  };

  return (
    <div className={ styles.symbolImage } >
        <Image src={ "/symbol_" + params.symbolName + ".jpg" } alt={ params.symbolName } width={ 300 } height={ 300 } />
    </div>
  );
}


Then we add a paragraph styled using CSS class symbolText. The HTML in here will be the current property of texts being pointed to by symbolName.

src/app/symbol/[symbolName]/page.js
return (
  <div className={ styles.symbolImage } >
      <Image src={ "/symbol_" + params.symbolName + ".jpg" } alt={ params.symbolName } width={ 300 } height={ 300 } />
      <p className={styles.symbolText} >{ texts[params.symbolName] }</p>
  </div>
);


The symbolText CSS class just imposes some padding.

src/app/page.module.css
.symbolImage {
  width: 100%;
  min-height: auto;
  margin: 10px auto 10px auto;
  text-align: center;
}

.symbolImage img{
  border-radius: 10px;
}

.symbolText {
  padding: 10px;
}


.generationContainer {
  width: 500px;
  margin: 0 auto 0 auto;
}


You see the paragraph appears!


We're done for the time being. So far, we've covered a bit of NextJS routing and built-in components.

Next

Form validation, submitting and API usage.