I am trying to generate identifiers for my Post model using a text file which I achieved successfully.
When I go to delete a Post I have to shift all postId -1.
I do this because in my template I am iterating through the posts and I have a postIdentifier variable that maps to that specific post so when a post gets deleted I must shift all postId's minus 1 so the postIdentifier variable properly matches to the specific post to edit or delete.
NOTE: I am trying to maintain both the text file and the database with the postIds shifted -1.
The issue I am dealing with is copying the contents of one file to another.
When I try to copy fileSystem.copyFileSync(constantVariable.FILE_PATH_TO_POST_SHIFT_IDENTIFIERS, constantVariable.FILE_PATH_POST_IDENTIFIERS). it copies a blank file even though there is content in it.
I decided to try to switch the source and destination variables around and it works that way but this is not what I want.
Why is copyFileSync() copying a blank file?
/* deletePost.js */
var express = require('express');
const Post = require("../models/post")
const Account = require("../models/account")
const sessionStorage = require("sessionstorage")
const constantVariable = require("../public/javascripts/constantVariables")
const fileSystem = require("fs")
var router = express.Router();
/* GET delete post page. */
router.get('/:postId', function(req, res, next) {
var numberId = Number(req.params.postId)
// Collect the identifier so we can delete the specific instance later.
sessionStorage.setItem("deleteIdentifier", numberId)
Post.findOne({postId: numberId}).exec(function(err, post) {
Account.findOne({email: req.session.email}).exec(function(err, account) {
res.render("deletePost", { title: "Social Application", post: post, account: account})
})
})
});
/* POST delete post */
router.post("/", function(req, res, next) {
Post.findOneAndRemove({postId: sessionStorage.getItem("deleteIdentifier")}, function(err, post) {
if (err) {
console.log(err)
} else {
console.log("Removed post: " post)
}
})
// Get the file contents then find and replace identifier.
var postIdentifiers = fileSystem.readFileSync(constantVariable.FILE_PATH_POST_IDENTIFIERS, {encoding: "utf-8"})
var newValue = postIdentifiers.replace(sessionStorage.getItem("deleteIdentifier").toString(), "")
// Write the replacement value to the file.
fileSystem.writeFileSync(constantVariable.FILE_PATH_POST_IDENTIFIERS, newValue)
// Write all the contents from postIds.txt to postShiftIds.txt - 1.
var readable = fileSystem.createReadStream(constantVariable.FILE_PATH_POST_IDENTIFIERS, {encoding: "utf-8"})
readable.on("readable", function() {
var id = ""
var parsedId = 0
var shiftedId = 0
while ((id = readable.read(1)) !== null) {
parsedId = parseInt(id)
if (parsedId !== 0) {
parsedId -= 1
shiftedId = parsedId
}
// Write the shifted identifier to postShiftIds.txt - 1.
fileSystem.appendFileSync(constantVariable.FILE_PATH_TO_POST_SHIFT_IDENTIFIERS, shiftedId.toString())
}
})
// Copy the shifted identifiers to the original file.
fileSystem.copyFileSync(constantVariable.FILE_PATH_TO_POST_SHIFT_IDENTIFIERS, constantVariable.FILE_PATH_POST_IDENTIFIERS)
// Shift all the post identifiers down one.
Post.find({}).exec(function(err, posts) {
if (err) {
console.log(err)
} else {
var package = {}
posts.forEach((post) => {
// Dont subtract the first id.
if (post.postId === 0) {
package = {
postId: post.postId,
emailId: post.emailId,
postTitle: post.postTitle,
postMessage: post.postMessage
}
} else {
package = {
postId: post.postId - 1,
emailId: post.emailId,
postTitle: post.postTitle,
postMessage: post.postMessage
}
}
Post.findOneAndUpdate({postId: post.postId}, package, {new: true}, function(err, post) {
if (err) {
console.log(err)
} else {
console.log("Shifted index: ", post)
}
})
})
}
})
res.redirect("allPosts")
})
/* allPosts.pug */
extends mainApplicationLayout
block content
- var accountEmail = ""
- var emailId = ""
- var pathToEditPost = ""
- var pathToDeletePost = ""
- var postIdentifier = 0
each account in accounts
- accountEmail = account.email
each post in posts
- emailId = post.emailId
//- If the unique email address from the account matches the email id of the post then we will display that information.
if (emailId === accountEmail)
br
div(class="container")
div(class="jumbotron")
p(class="float-end text-muted")= post.datePosted.toLocaleDateString()
img(src=account.accountPhoto class="rounded-circle" width="80" height="80" alt="Profile photo")
h5= account.name " " account.lastName
hr
div(class="container")
h5: b #{post.postTitle}
p(class="text-muted")= post.postMessage
hr
p(class="float-end text-muted")= post.datePosted.toLocaleTimeString("en-US", {hour: '2-digit', minute: '2-digit'})
- pathToEditPost = "/editPost" '/' postIdentifier.toString()
- pathToDeletePost = "/deletePost" '/' postIdentifier.toString()
//- Increment the index for post identifers.
- postIdentifier = 1
a(href=pathToEditPost class="float-start"): button(class="btn-sm btn-primary mx-1") Edit post
a(href=pathToDeletePost class="text-danger float-start"): button(class="btn-sm btn-danger mx-1") Delete post
br
br
br
CodePudding user response：
I would put a log in right before the copy command:
// Copy the shifted identifiers to the original file.
console.log(
'ARGUMENTS',
constantVariable.FILE_PATH_TO_POST_SHIFT_IDENTIFIERS,
constantVariable.FILE_PATH_POST_IDENTIFIERS,
);
fileSystem.copyFileSync(
constantVariable.FILE_PATH_TO_POST_SHIFT_IDENTIFIERS,
constantVariable.FILE_PATH_POST_IDENTIFIERS,
);
and then I would read in the console what is being passed in, and then maybe try same thing in the node repl:
$ node
> const fileSystem = require("fs");
> fileSystem.copyFileSync(... arguments from log);
and then see if the file gets copied where you want it. You might figure out the issue in either step
CodePudding user response：
All I had to do was move the fileSystem.appendFileSync(constantVariable.FILE_PATH_TO_POST_SHIFT_IDENTIFIERS, shiftedId.toString())
to a different spot here is what it looks like now:
/* deletePost.js */
/* POST delete post */
router.post("/", function(req, res, next) {
Post.findOneAndRemove({postId: sessionStorage.getItem("deleteIdentifier")}, function(err, post) {
if (err) {
console.log(err)
} else {
console.log("Removed post: " post)
}
})
// Get the file contents then find and replace identifier.
var postIdentifiers = fileSystem.readFileSync(constantVariable.FILE_PATH_POST_IDENTIFIERS, {encoding: "utf-8"})
var newValue = postIdentifiers.replace(sessionStorage.getItem("deleteIdentifier").toString(), "")
// Write the replacement value to the file.
fileSystem.writeFileSync(constantVariable.FILE_PATH_POST_IDENTIFIERS, newValue)
// Write all the contents from postIds.txt to postShiftIds.txt - 1.
var readable = fileSystem.createReadStream(constantVariable.FILE_PATH_POST_IDENTIFIERS, {encoding: "utf-8"})
readable.on("readable", function() {
var id = ""
var parsedId = 0
var shiftedId = 0
while ((id = readable.read(1)) !== null) {
parsedId = parseInt(id)
if (parsedId !== 0) {
parsedId -= 1
shiftedId = parsedId
}
// Write the shifted identifier to postShiftIds.txt - 1.
fileSystem.appendFileSync(constantVariable.FILE_PATH_TO_POST_SHIFT_IDENTIFIERS, shiftedId.toString())
}
// ********************** [NEW LOCATION] **********************
// Copy the shifted identifiers to the original file.
fileSystem.copyFileSync(constantVariable.FILE_PATH_TO_POST_SHIFT_IDENTIFIERS, constantVariable.FILE_PATH_POST_IDENTIFIERS)
})
// Shift all the post identifiers down one.
Post.find({}).exec(function(err, posts) {
if (err) {
console.log(err)
} else {
var package = {}
posts.forEach((post) => {
// Dont subtract the first id.
if (post.postId === 0) {
package = {
postId: post.postId,
emailId: post.emailId,
postTitle: post.postTitle,
postMessage: post.postMessage
}
} else {
package = {
postId: post.postId - 1,
emailId: post.emailId,
postTitle: post.postTitle,
postMessage: post.postMessage
}
}
Post.findOneAndUpdate({postId: post.postId}, package, {new: true}, function(err, post) {
if (err) {
console.log(err)
} else {
console.log("Shifted index: ", post)
}
})
})
}
})
res.redirect("allPosts")
})
module.exports = router;