Function doesn't return the right value - arduino

Question

To begin with, I'm doing a mini project on the verification of RFID card using NodeMCU. I set up a database and a server to handle all the requests from the client. The problem is, whenever I try to verify a valid card, the function that handles it keeps returning the wrong value.
To be clear, here is my main loop:
void loop() {
connectToHost();
key = kpd.getKey();
card = readCard();
delay(200);
//check for card status
if(verifyCard(card)){
Serial.println("Card is valid");
} else {
Serial.println("Invalid Card");
}
//check connection status
if(WiFi.status() == WL_CONNECTION_LOST){
connectToWiFi();
}
}
The main loop calls this function:
boolean verifyCard(String uid){
String url = "/ECafe/terminal_verify.php?uid=";
url += uid;
// This will send the request to the server
Serial.print("Requesting URL: ");
Serial.println(url);
client.print(String("GET ") + url + " HTTP/1.1\r\n" +
"Host: " + host + "\r\n" +
"Connection: close\r\n\r\n");
unsigned long timeout = millis();
while (client.available() == 0) {
if (millis() - timeout > 5000) {
Serial.println(">>> Client Timeout !");
client.stop();
}
yield();
}
// Read all the lines of the reply from server and print them to Serial
while (client.available()) {
String line = client.readStringUntil('\r');
//if string contains echo from php file
if(line.indexOf("Valid")>0){
return true;
} else {
return false;
}
yield();
}
Serial.println();
Serial.println("Closing connection");
}
I intentionally put a valid card UID in the database just to test this function. Yet, it keeps returning false. I'm sure that the response from the server is "Valid". I suspect that the function doesn't even wait for the response from the server and returns a false value because the interval between the GET request is sent and the response is returned is too short. Is that because of the if condition in the main loop? See the attachment for the serial monitor output.

Answer 1

The logic of your function is flawed.
// Read all the lines of the reply from server and print them to Serial
while (client.available()) {
String line = client.readStringUntil('\r');
//if string contains echo from php file
if(line.indexOf("Valid")>0){
return true;
} else {
return false;
When the code reads the first line, and it doesn't contain Valid, it will fail and return false. So your code will ALWAYS return false, as I doubt that the first line returned is Valid...
}
yield();
}
Serial.println();
Serial.println("Closing connection");
The rest of this code is never executed. "Closing connection" is never printed right?