So I have an issue where data that's encoded using php is not decoding properly in javascript. Here is the error: Error
The JSON looks fine but javascript is throwing an error and I have no idea why.
Here is my code:
JS:
function requestData( url )
{
document.getElementById( "spinner" ).style.visibility = "visible";
var xhttp;
xhttp = new XMLHttpRequest( );
xhttp.onreadystatechange = function( ) {
if ( this.readyState == 4 ) {
if( this.status == 200 )
{
document.getElementById( "spinner" ).style.visibility = "hidden";
console.log( this.responseText );
return this.responseText;
}
else
{
document.getElementById( "spinner" ).style.visibility = "hidden";
document.getElementById( "errorsec" ).innerHTML = ":( An unknown error has happened and your request was canceled. Code: " + this.status;
return false;
}
}
};
xhttp.open( "GET", url, true );
xhttp.send( );
}
function handleSignup( )
{
var username = document.getElementById( "un" ).value; // Get text field values
var password = document.getElementById( "pw" ).value;
var requestObject = requestData( "../../FRAMEWORK/createaccount.php?name=" + username + "&password=" + password, false );
var returnObject;
if( requestObject != false )
{
requestObject = JSON.parse( requestObject );
console.log( returnObject.value );
}
}
PHP:
<?php
# REV 1.0.0
$name = $_GET[ "name" ]; # Get values to set
$password = $_GET[ "password" ];
$file = fopen( "../USER_STORE/userindex.json", "r" ); # Load user index
$accounts = json_decode( fread($file, filesize( "../USER_STORE/userindex.json" ) ), true );
fclose($file);
$alreadyExists = false; # Check to see if username already is in use
foreach($accounts as $val) {
if( $val == $name )
{
$alreadyExists = true;
}
}
if( !$alreadyExists ) # If username is not in use
{
$UUID = sizeof( $accounts ) + 1;
$toAppend = array( "username" => $name, "password" => hash( "sha256", $password ) ); # Create append list
mkdir( "../USER_STORE/" . $UUID ); # Append user data
$file = fopen( "../USER_STORE/" . $UUID . "/accountinfo.json", "w" );
fwrite( $file, json_encode( $toAppend ) );
fclose( $file );
$accounts[ $UUID ] = $name; # Create new user index
$file = fopen( "../USER_STORE/userindex.json", "w" ); # Update userindex
fwrite( $file, json_encode( $accounts ) );
fclose( $file );
$return = array( "value" => "created" ); # Return message
echo( json_encode( $return ) );
}
else # Account is in use
{
$return = array( "value" => "account_in_use" ); # Return error message
echo( json_encode( $return ) );
}
?>
XMLHttpRequest
works asynchronously. So your function requestData
ends after the xhttp.send();
and does not return anything. The event handler for readystatechange
(which is called a bit later, once XMLHttpRequest
actually receives the response from the server) does return a value, but nothing is done with it.
Solution: move parsing and interpretation of the response in that event handler.
Additional notes:
When you build an URL, you need to escape (using encodeURIComponent
) the parameters. What do you think will happen if any of the two fields contains spaces, or special characters such as %
or &
?
When you hash a password, you have to salt it first. Or use a ready-made function such as password_hash
which will do it for you.
You may want to use file_get_contents
/ file_put_contents
to read/write your user file, that will simplify your code quite a bit. Or better yet, a database.