sse

dependencies.js

@@ -37,4 +37,6 @@ FOREIGN KEY (transaction_id) REFERENCES transactions (transaction_id) FOREIGN KE
 );
 `)
 
+
+
 module.exports = db

index.js

@@ -47,6 +47,7 @@ app.use( express.static( __dirname + '/frontend'))
 const accountsRoute = require("./routes/accounts");
 const transactionsRoute = require("./routes/transactions");
 const resetRoute = require("./routes/reset")
+const { sse } = require("./sse")
 
 const basepath = "/api/v1";
 
@@ -54,7 +55,7 @@ app.use(`${basepath}/accounts`, accountsRoute);
 app.use(`${basepath}/transactions`, transactionsRoute);
 app.use(`${basepath}/`, resetRoute.router);
 
-app.get("/live", resetRoute.mysse)
+app.get("/live", sse)
 
 
 app.get("/", (req, res) => {
@@ -64,3 +65,4 @@ app.get("/", (req, res) => {
 app.listen(port, () => {
     console.log(`App listening on port ${port}`);
 });
+

routes/accounts.js

@@ -2,7 +2,7 @@ const express = require("express");
 const router = express.Router();
 
 const db = require("../dependencies");
-const { update } = require("./reset");
+const {send_sse_update} = require("../sse")
 
 // Fix if balance is null
 function fix_balance_is_null(acc) {
@@ -84,12 +84,8 @@ router.post("/", (req, res) => {
         .run(number, name, qualifiedName, des, type, req.body.parentAccount);
     
     res.status(204).send();
+    send_sse_update();
     
-    for (res of update.values()) {
-        // res.write("data: update\n\n")
-        res.write("event: update\n");
-        res.write("data: {}\n\n");
-    }
 });
 
 router.get("/:account", (req, res) => {
@@ -160,11 +156,8 @@ router.put("/:account", (req, res) => {
         });
     } else {
         res.status(204).send();
-        for (res of update.values()) {
-            // res.write("data: update\n\n")
-            res.write("event: update\n");
-            res.write("data: {}\n\n");
-        }
+        send_sse_update();
+
     }
 });
 
@@ -182,12 +175,7 @@ router.delete("/:account", (req, res) => {
     } else {
         res.status(200).send();
     }
-
-    for (res of update.values()) {
-        // res.write("data: update\n\n")
-        res.write("event: update\n");
-        res.write("data: {}\n\n");
-    }
+    send_sse_update();
 });
 
 module.exports = router;

routes/reset.js

@@ -2,35 +2,13 @@ const express = require('express');
 const router = express.Router();
 
 const db = require("../dependencies");
+const {send_sse_update} = require("../sse")
 
 router.post("/reset", (req, res) => {
     db.exec("DELETE FROM accounts; DELETE FROM transaction_entries; DELETE FROM transactions")
 
     res.status(204).send()
+    send_sse_update()
 })
 
-const update = new Map()
-async function mysse(req, res) {
-    console.log('Got /events');
-    
-    res.set({
-        'Cache-Control': 'no-cache',
-        'Content-Type': 'text/event-stream',
-        'Connection': 'keep-alive'
-    });
-    res.flushHeaders();
-
-
-    // Tell the client to retry every 10 seconds if connectivity is lost
-    res.write('retry: 10000\n\n');
-    update.set(req.sessionId, res)
-    console.log("connected")
-
-    res.on("close", () => {
-        update.delete(req.sessionId)
-        res.end()
-    })
-};
-
-
-module.exports = { router, mysse, update};
+module.exports = { router};

routes/transactions.js

@@ -2,7 +2,7 @@ const express = require('express');
 const router = express.Router();
 
 const db = require("../dependencies");
-const { update } = require("./reset")
+const {send_sse_update} = require("../sse")
 
 router.get("/", (req, res) => {
     const transactions = db.prepare("SELECT transaction_id as id, postingDate, valueDate, title FROM transactions").all();
@@ -30,11 +30,7 @@ router.post("/", (req, res) => {
     res.send({
         id: db_transaction.lastInsertRowid
     })
-    for (res of update.values()) {
-        // res.write("data: update\n\n")
-        res.write('event: update\n');
-        res.write('data: {}\n\n');
-    }
+    send_sse_update()
 
 })
 
@@ -56,12 +52,8 @@ router.put("/:id", (req, res) => {
         const db_entries = db.prepare("INSERT INTO transaction_entries (transaction_id, account_name, amount, label) VALUES (?, ?, ?, ?)").run(req.params.id, req.body.entries[i].account, req.body.entries[i].amount, req.body.entries[i].label)
     }
 
-
+    send_sse_update()
     res.status(204).send()
-    for (res of update.values()) {
-        res.write('event: update\n');
-        res.write('data: {}\n\n');
-    }
 
 })
 
@@ -71,12 +63,7 @@ router.delete("/:id", (req, res) => {
 
 
     res.status(204).send()
-    for (res of update.values()) {
-        // res.write("data: update\n\n")
-        res.write('event: update\n');
-        res.write('data: {}\n\n');
-    }
-
+    send_sse_update()
 })
 
 module.exports = router;

sse.js

@@ -0,0 +1,42 @@
+let newcode = false;
+//helferfunktion die das richtige format für das event erstellt 
+function sendMessage(response, eventname, datacontent) {
+    //response.write ist ein append, also schreibt was ans ende der seite 
+    
+    response.write('event: ' + eventname + '\n' + 'data: ' + JSON.stringify(datacontent) + '\n\n')
+    newcode = false;
+}
+
+function send_sse_update() {
+    newcode = true;
+}
+
+
+async function sse(request, response) {
+
+    //header so setzen 
+    response.set({
+        'Cache-Control': 'no-cache',
+        'Content-Type': 'text/event-stream',
+        'Connection': 'keep-alive'
+    })
+    response.flushHeaders();
+    //loop, schickt ein event, wartet 5 sekunden, schickt dann erneut. 
+    // so abändern, dass anderer code in den loop hineingreifen kann (variable bool "newcode" oder so)
+    //dann wenn newcode = true, schicke ein eben via sendlive)
+    //der loop muss glaube ich bestehen bleiben
+    while (true){
+        if (newcode) {
+            console.log("update send")
+            sendMessage(response, 'update', {})
+        } else {
+            sendMessage(response,'hello', {})
+        }
+        // response.write()
+        await new Promise(resolve => setTimeout(resolve, 5000))
+        console.log(newcode)
+    }
+
+}
+
+module.exports = { sse, send_sse_update }