Exploring the concepts of express post and delete responses that are unclear

Question

Exploring the concepts of express post and delete responses that are unclear

It appears that I am facing an issue where trying to access an attribute of an element from a JSON file returns null. Additionally, I am still encountering npm audit problems. What are your thoughts on this situation?

Below is the code snippet that has been edited:

export const data = require('./file.json');
export let DATA = data as Type[]; 

let temp = DATA;

app.post('/api/tickets', (req, res) => {
    // Load previous data into a JSON string
    const past_data = JSON.stringify(temp);
    // Load new data into a JSON string
    const new_element = JSON.stringify(req.params.formData)
    if (new_element !== "") {
        // Concatenate both strings into one JSON string and write it into fs
        fs.writeFile("./file.json",[past_data,new_element],(err) => {
            if (err) throw err;
        });
    }

    // Send the response back with the new data
    const new_data = JSON.parse([past_data,new_element].toString());
    res.send(new_data);
});

app.delete('/api/tickets/:id', (req, res) => {
    // Find the requested ticket based on id in the global temp
    const ticket = temp.find(t => t.id === (req.params.id));
    if (typeof ticket !== 'undefined') {
        const index = temp.indexOf(ticket);
        // Remove the ticket from the global temp
        temp.splice(index, 1)
    }

    // Create a JSON string out of the modified global temp
    const data_after_delete = JSON.stringify(temp);

    // Write the data directly into fs
    fs.writeFile("./file.json",data_after_delete,(err) => {
        if (err) throw err;
    });

    // Send the updated data back to the requester
    const new_data = JSON.parse(data_after_delete);
    res.send(new_data);
});

One object from the json file before any modification:

[
  {
    "id": "81a885d6-8f68-5bc0-bbbc-1c7b32e4b4e4",
    "title": "Need a Little Help with Your Site? Hire a Corvid Web Developer",
    "content": "Here at Wix we strive to support you with this community forum, API references, articles, videos and code examples. But sometimes you might need a little extra help to get your site exactly the way you want it. \nHire a developer from the Wix Arena, an online marketplace with top Corvid web developers from around the world. Submit your project details here, and we’ll find the right professional for you.",
    "userEmail": "<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="b7ddc2d0f7d9d2c4d2c3d6db99d6d1">[email protected]</a>",
    "creationTime": 1542111235544,
    "labels": ["Corvid", "Api"]
  },

One object from the json file after being modified:

["[\"[\\\"[\\\\\\\"[{\\\\\\\\\\\\\\\"id\\\\\\\\\\\\\\\":\\\\\\\\\\\\\\\"81a885d6-8f68-5bc0-bbbc-1c7b32e4b4e4\\\\\\\\\\\\\\\",\\\\\\\\\\\\\\\"title\\\\\\\\\\\\\\\":\\\\\\\\\\\\\\\"Need a Little Help with Your Site? Hire a Corvid Web Developer\\\\\\\\\\\\\\\",\\\\\\\\\\\\\\\"content\\\\\\\\\\\\\\\":\\\\\\\\\\\\\\\"Here at Wix we strive to support you with this community forum, API references, articles, videos, and code examples. Sometimes, additional assistance may be required to align your site precisely as desired. \\\\\\\\\\\\\\\\nHire a developer from the Wix Arena, an online marketplace featuring top Corvid web developers worldwide. Share your project details here, and we will connect you with the ideal professional.\\\\\\\\\\\\\\\",\\\\\\\\\\\\\\\"userEmail\\\\\\\\\\\\\\\":\\\\\\\\\\\\\\\"<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="7e140b193e101b0d1b0a1f12501f18">[email protected]</a>\\\\\\\\\\\\\\\",\\\\\\\\\\\\\\\"creationTime\\\\\\\\\\\\\\\":1542111235544,\\\\\\\\\\\\\\\"labels\\\\\\\\\\\\\\\":[\\\\\\\\\\\\\\\"Corvid\\\\\\\\\\\\\\\",\\\\\\\\\\\\\\\"Api\\\\\\\\\\\\\\\"]},

javascript express

Answer 1

Answer №1

For proper file handling, remember to use JSON.stringify when writing data to a file and JSON.parse when reading from a file (unless you are using require which handles parsing implicitly). It's important to manipulate your data as plain objects and arrays rather than as JSON strings to avoid damaging the structure.

export let DATA: Type[] = require('./file.json');
function save() {
    const jsonString = JSON.stringify(DATA);
//                     ^^^^^^^^^^^^^^^^^^^^^ call it only here
    fs.writeFile("./file.json", jsonString, (err) => {
        if (err) throw err;
    });
}

app.post('/api/tickets', (req, res) => {
    if (req.params.formData) {
        const new_element = req.params.formData; // JSON.parse() may be needed if it's a JSON string
        // manipulate array to add new element
        DATA.push(new_element);
        save();
    }
    // respond with updated data
    res.send(DATA);
});

app.delete('/api/tickets/:id', (req,res) => {
    // find requested ticket by id in global data
    const ticket = DATA.findIndex(t => t.id === (req.params.id));
    if (ticket !== -1) {
        // remove specified ticket from data
        DATA.splice(index, 1);
        save();
    }
    // send back updated data
    res.send(DATA);
});

Answer 2

For proper file handling, remember to use JSON.stringify when writing data to a file and JSON.parse when reading from a file (unless you are using require which handles parsing implicitly). It's important to manipulate your data as plain objects and arrays rather than as JSON strings to avoid damaging the structure.

export let DATA: Type[] = require('./file.json');
function save() {
    const jsonString = JSON.stringify(DATA);
//                     ^^^^^^^^^^^^^^^^^^^^^ call it only here
    fs.writeFile("./file.json", jsonString, (err) => {
        if (err) throw err;
    });
}

app.post('/api/tickets', (req, res) => {
    if (req.params.formData) {
        const new_element = req.params.formData; // JSON.parse() may be needed if it's a JSON string
        // manipulate array to add new element
        DATA.push(new_element);
        save();
    }
    // respond with updated data
    res.send(DATA);
});

app.delete('/api/tickets/:id', (req,res) => {
    // find requested ticket by id in global data
    const ticket = DATA.findIndex(t => t.id === (req.params.id));
    if (ticket !== -1) {
        // remove specified ticket from data
        DATA.splice(index, 1);
        save();
    }
    // send back updated data
    res.send(DATA);
});

Exploring the concepts of express post and delete responses that are unclear

Answer №1

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