best practices

Luukth · Jul 19, 2020 · df82962 · df82962
1 parent 23f3e99
commit df82962
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Showing 3 changed files with 165 additions and 15 deletions.
diff --git a/express-postgres/index.html b/express-postgres/index.html
@@ -7,7 +7,7 @@
     <title>Document</title>
 </head>
 <body>
-    <h1>MY BEST TODO APP EVER</h1>
+    <h1>MY TODO APP</h1>
     <ol id = 'olTodo'>
 
     </ol>
@@ -18,11 +18,11 @@ <h1>MY BEST TODO APP EVER</h1>
     btnCreate.addEventListener("click", async e=> {
                     const jsonRequest = {}
                     jsonRequest.todo = prompt("Enter your todo item!")
-                    const result = await fetch("http://localhost:8080/todos", {method: "POST", 
+                    let result = await fetch("http://localhost:8080/todos", {method: "POST", 
                     headers: {"content-type": "application/json"}, body: JSON.stringify(jsonRequest) })
-                    const success = await result.json();
+                    result = await result.json();
                     readTodos()
-                    alert("CREATED! ")
+                    if (!result.success)  alert("FAILED! ")
 
      })
     readTodos();
@@ -42,11 +42,12 @@ <h1>MY BEST TODO APP EVER</h1>
                 li.addEventListener("click", async e => {
                     const jsonRequest = {}
                     jsonRequest.id = e.target.id;
-                    const result = await fetch("http://localhost:8080/todos", {method: "DELETE", 
+                    let result = await fetch("http://localhost:8080/todos", {method: "DELETE", 
                     headers: {"content-type": "application/json"}, body: JSON.stringify(jsonRequest) })
-                    const success = await result.json();
+                    result  = await result.json();
                     readTodos();
-                    alert("Deleted! ")
+                    if (!result.success)  alert("FAILED! ")
+
                 })
                 olTodo.appendChild(li)
             })

diff --git a/express-postgres/newserver.js b/express-postgres/newserver.js
@@ -0,0 +1,149 @@
+//using pool is better for web apps so that we can 
+//reserve a client connection for each request and 
+//avoid problems with concurrent requests.. 
+//Check out this video I discuss this in details
+//https://www.youtube.com/watch?v=GTeCtIoV2Tw
+//I Changed all the singelton clients in this code to Pool
+
+const {Pool} = require("pg")
+const express = require ("express")
+const app = express();
+app.use(express.json())
+
+const dbReadPool = new Pool({
+    "user": "dbread",
+    "password" : "dbread",
+    "host" : "husseinmac",
+    "port" : 5432,
+    "database" : "todo"
+})
+
+
+const dbDeletePool = new Pool({
+    "user": "dbdelete",
+    "password" : "dbdelete",
+    "host" : "husseinmac",
+    "port" : 5432,
+    "database" : "todo"
+})
+
+
+const dbCreatePool = new Pool({
+    "user": "dbcreate",
+    "password" : "dbcreate",
+    "host" : "husseinmac",
+    "port" : 5432,
+    "database" : "todo"
+})
+
+app.get("/", (req, res) => res.sendFile(`${__dirname}/index.html`))
+
+app.get("/todos", async (req, res) => {
+    const rows = await readTodos();
+    res.setHeader("content-type", "application/json")
+    res.send(JSON.stringify(rows))
+})
+
+
+
+app.post("/todos", async (req, res) => {
+    let result = {}
+    try{
+        const reqJson = req.body;
+        result.success = await createTodo(reqJson.todo)
+    }
+    catch(e){
+        result.success=false;
+    }
+    finally{
+        res.setHeader("content-type", "application/json")
+        res.send(JSON.stringify(result))
+    }
+
+})
+
+
+
+
+
+app.delete("/todos", async (req, res) => {
+    let result = {}
+    try{
+
+        const reqJson = req.body;
+        result.success = await deleteTodo(reqJson.id)
+    }
+    catch(e){
+        result.success=false;
+    }
+    finally{
+        res.setHeader("content-type", "application/json")
+        res.send(JSON.stringify(result))
+    }
+
+})
+
+
+app.listen(8080, () => console.log("Web server is listening.. on port 8080"))
+
+start()
+
+async function start() {
+    await connect();
+    /*
+    const todos = await readTodos();
+    console.log(todos)
+
+    const successCreate = await createTodo("Go to trader joes")
+    console.log(`Creating was ${successCreate}`)
+
+    const successDelete = await deleteTodo(1)
+    console.log(`Deleting was ${successDelete}`)
+    */
+}
+
+async function connect() {
+    try {
+        await dbCreatePool.connect();
+        await dbDeletePool.connect();
+        await dbReadPool.connect();
+    }
+    catch(e) {
+        console.error(`Failed to connect ${e}`)
+    }
+}
+
+async function readTodos() {
+    try {
+    const results = await dbReadPool.query("select id, text from todos");
+    return results.rows;
+    }
+    catch(e){
+        return [];
+    }
+}
+
+async function createTodo(todoText){
+
+    try {
+        await dbCreatePool.query("insert into todos (text) values ($1)", [todoText]);
+        return true
+        }
+        catch(e){
+            return false;
+        }
+}
+
+
+
+async function deleteTodo(id){
+
+    try {
+        await dbDeletePool.query("delete from todos where id = $1", [id]);
+        return true
+        }
+        catch(e){
+            return false;
+        }
+}
+
diff --git a/express-postgres/server.js b/express-postgres/server.js
@@ -18,6 +18,7 @@ const pool = new Pool({
     "database" : "todo"
 })
 
+
 app.get("/", (req, res) => res.sendFile(`${__dirname}/index.html`))
 
 app.get("/todos", async (req, res) => {
@@ -31,10 +32,8 @@ app.get("/todos", async (req, res) => {
 app.post("/todos", async (req, res) => {
     let result = {}
     try{
-
         const reqJson = req.body;
-        await createTodo(reqJson.todo)
-        result.success= true;
+        result.success = await createTodo(reqJson.todo)
     }
     catch(e){
         result.success=false;
@@ -55,8 +54,7 @@ app.delete("/todos", async (req, res) => {
     try{
 
         const reqJson = req.body;
-        await deleteTodo(reqJson.id)
-        result.success= true;
+        result.success = await deleteTodo(reqJson.id)
     }
     catch(e){
         result.success=false;
@@ -90,6 +88,8 @@ async function start() {
 async function connect() {
     try {
         await pool.connect();
+        await pool.connect();
+        await pool.connect();
     }
     catch(e) {
         console.error(`Failed to connect ${e}`)
@@ -98,7 +98,7 @@ async function connect() {
 
 async function readTodos() {
     try {
-    const results = await pool.query("select id, text from todos");
+    const results = await postgres.query("select id, text from todos");
     return results.rows;
     }
     catch(e){
@@ -109,7 +109,7 @@ async function readTodos() {
 async function createTodo(todoText){
 
     try {
-        await pool.query("insert into todos (text) values ($1)", [todoText]);
+        await postgres.query("insert into todos (text) values ($1)", [todoText]);
         return true
         }
         catch(e){
@@ -122,7 +122,7 @@ async function createTodo(todoText){
 async function deleteTodo(id){
 
     try {
-        await pool.query("delete from todos where id = $1", [id]);
+        await postgres.query("delete from todos where id = $1", [id]);
         return true
         }
         catch(e){