Code Samples

Saturday, June 10, 2017

PayWay Rest API: Create Refund From PayWay Payment

PayWay Rest API: Create Payment Using Stored Credit Card Token

PayWay Rest API: Create Customer Create Token

PayWay Rest API: Create Credit Card Payment

PayWay Rest API: Check if Rest API credentials are valid

PayWay Rest API is easy to implement. We need three information from PayWay end to create payment, refund payment, void payment, store credit card for further use and many other things.


So we need:

1. Publishable public key

2. Secret private key





3. and Merchant ID





Now you have all 3 information to communicate with PayWay.


Below is a PHP script to test credentials using rest API:



<?php
include_once "CurlExecutor.php";

define("BASE_URL", "https://api.payway.com.au/rest/v1");
define("MERCHANT_ID", "TEST");
define("PRIVATE_KEY", "T10487_SEC_...");
define("PUBLIC_KEY", "T10487_PUB_...");

$headers[] = "Authorization: Basic " . base64_encode(PUBLIC_KEY . ":");
$result = CurlExecutor::execute(BASE_URL, "GET", null, null, $headers);
$result["response"] = json_decode($result["response"]);
CurlExecutor::prettyPrint($result);
?>




If your credentials are fine below output will back from PayWay end:



Array
(
    [code] => 200
    [response] => stdClass Object
        (
            [clientNumber] => T52943
            [clientName] => Pritom
            [keyName] => T10487_PUB...bzq
            [links] => Array
                (
                    [0] => stdClass Object
                        (
                            [rel] => single-use-tokens
                            [href] => https://api.payway.com.au/rest/v1/single-use-tokens
                        )

                    [1] => stdClass Object
                        (
                            [rel] => surcharges
                            [href] => https://api.payway.com.au/rest/v1/surcharges
                        )

                    [2] => stdClass Object
                        (
                            [rel] => help
                            [href] => https://www.payway.com.au/docs/rest.html#resources
                        )

                )

        )

)



If you have error in your public key below output will be generated:



Array
(
    [code] => 401
    [response] => stdClass Object
        (
            [message] => The "Authorization" header contained an unknown API key. You must send your API key as the basic authentication username.
            [links] => Array
                (
                    [0] => stdClass Object
                        (
                            [rel] => help
                            [href] => https://www.payway.com.au/docs/rest.html#authentication
                        )

                )

        )

)

Friday, June 9, 2017

Lock wait timeout exceeded; try restarting transaction

Why is happening like this, some other thread is holding a record lock on some record (you're updating every record in the table!) for too long, and your thread is being timed out. That's why you got this error.

Your first step to lookup for which queries this problem happened.

Below are some queries to observe transaction status and other data:

show open tables where in_use > 0;
show processlist;
SELECT * FROM `information_schema`.`innodb_trx` ORDER BY `trx_started`;
SELECT * FROM `information_schema`.`innodb_locks`;
show variables like 'innodb_lock_wait_timeout';
show variables like '%wait_timeout%';

Above queries help you to find out why the problem occurs. 

Now you can check your database transaction isolation level in the mysql using following command:

SELECT @@GLOBAL.tx_isolation, @@tx_isolation, @@session.tx_isolation;

I think all values are set to "REPEATABLE-READ" if you don't configured it yet.

Make sure the database tables are using InnoDB storage engine and READ-COMMITTED transaction isolation level.

Now you can set it to "READ-COMMITTED" for better performance using below command:

SET GLOBAL TRANSACTION ISOLATION LEVEL READ COMMITTED;

If the the above configuration is correct then please try to increase the database server innodb_lock_wait_timeout variable to 500 (it's a random value, default value is 50).

Restart MySQL database service for the configuration to take place.

Modify MySQL startup options in the configuration file my.cnf (often named my.ini on Windows), so the transaction level is set to transaction-isolation = READ-COMMITTED.

And

innodb_lock_wait_timeout=500

If this not helps you much, you need and database administration as well as expert to troubleshoot the problem.

Saturday, June 3, 2017

PHP Tag Lib: PHP Custom Tag Library (TagLib)

We use tag in your HTML page such as "DIV", "H2", "P" etc in every moment in our life. Who used Grail's or Spring MVC he has knowledge on custom tag library. We can also use custom tag lib in PHP project. Below is a example of PHP custom tag lib usage:

<tglib:upper>Goes to upper</tglib:upper>

To drive output of this custom tag in PHP, you have to download and include tag lib library first from below link:

drive.google.com/PHP Tag Lib: PHP Custom Tag Library (TagLib)

We used tglib:upper in above script, so we have to make a directory in "TagLib" directory named "upper" with a function named "tglib___upper" that support $tag parameter. With will supply tag name as well as any attributes in that tag.

Below is a sample example of "upper" tag:

function tglib___upper($tag)
{
return strtoupper($tag['content']);
}

$tag["content"] contains body parts of the tag.

If you download and execute "tag1.php" file, below output will be generated:

Pages