README

DibiProxy

This is collection of "proxy drivers" for dibi database layer, which you can obtain on http://www.dibiphp.com

Why

Everyone knows the drill. When you're going to present something somewhere, you have whole project running on your local machine. This approach works for most of the cases, however we have been faced a problem. Let's outline:

The website we have presented is connected to our ERP system

Internet connection is not available in the meeting, our account manager has to present local installation

We did not feel comfortable putting whole ERP on our account managers laptop

So we decided to take another approach. Let's install the-least-needed database for the presentation. As the project has been using dibi as DBAL, we have created proxy classes instead.

How

The proxy classes sit on top of the actual database drivers, caching all the queries and their results. When database is not available, data are loaded from cache.

As some of the queries are changing data & are loading result ids, we implemented "override" concept, where the results are not cached by the query, but by the override key instead. So, data changing queries (like inserts) have pre-defined key under which they are saved & loaded from the cache later.

Installation

Simply put into your composer.json:

require {
  "foglcz/dibiproxy": "1.*"
}

Due to dibi driver loading process, you need to include appropiate driver before you use it:

require_once 'vendor/foglcz/dibiproxy/lib/drivers/your.selected.driver.php';

Then, just use the common driver with "Proxy" prefix and enable the proxying:

$config['driver'] = 'proxymysqli';
$config['proxy'] = 'path_to_proxy_file.dat';

If you have data-changing queries (inserts/update), you should then use different class for connecting to database:

dibiProxy::connect($config);

Afterwards, feel free to use the dibi:: class as usual for all data manipulation.

Usage

When using the "proxy" configuration parameter, you SHOULD supply the path to file, where proxy data will be saved. If you just provide "true", but not string, the classes will automatically create datafile in the place of lib/ class.

The classes work transparently, hence the update to proxying classes has no other steps. The proxying is used when no database connection is available. Our usage is, that we click-through the entire project on local machine while the connection is available - then we destroy the config parameters so that the project does NOT connect. This time, we verify the result - everything should work as default.

Data changing queries

If you have some update/insert/delete queries, which you want to include, before calling dibi::query() and/or $connection->* functions, you need to call override:

dibi::setProxyOverride('some.ident.of.the.query');

This will result in caching the query results under this static identifier. Hence, you can have database-changing queries running on proxied project.

Nette framework loading

If you're using Nette Framework (that awesome thing can be obtained at http://www.nette.org ) with the dibi driver within config.neon file, load the proxied classes this way:

database:
    driver: ProxyMysqli

services:
    database: DibiProxyConnection(%database%)

... which basically means exchanging the driver within config parameters & changing the connection class name (= changing DibiConnection --> DibiProxyConnection).

PHP 5.3 or 5.2

The DibiProxy classes exploit PHP 5.4 Trait fetature. However, as the Dibi has support for PHP 5.2, should you want to run DibiProxy on older version of php, you need to do one simple change.

First, pick the driver you want to use - eg. ProxyMysqli. That one is found within lib/drivers/ProxyMysqli.php
Edit the ProxyMysqli.php file and remove the "use" line
Open file lib/ProxyTrait.php and copy contents of the trait DibiProxyTrait { /* copy the content within brackets */ }
Put the content of the trait in place of the line, which contains use statement.
Copy the exception definitions from the bottom of the trait file, and put them into the driver file.

The resulting file would be then looking like this: https://gist.github.com/5464ca39375ddacf0041

Esentialy, this is what php parser does with traits. They are basically assisted copy-paste, wchich is precisely the reason why we used them.

Author and license

(these classes has been created within 2 hours during night hackathon before the presentation. Pull requests welcome.)

foglcz / dibiproxy

Maintainers

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