#44 Add order item read & link order with channel resource

[ronan-gloo]

Link to the issue

#44

Reason for this PR

• Order details were not accessible from the OrderResource object
• Channel info were not accessible from the OrderResource object

What does the PR do

Implements accessors for both

Unrelated changes

The AbstractResource::getProperty() method now accept a second argument, which indicates if the resource must loaded from the server to access to that property.

An usage example is here, where orders items are only provided when fetching a single resource:

https://github.com/shoppingflux/php-sdk/pull/47/files#diff-d7931d116e86a29bdd1e9ae70a77fcaaR104

Note that server request is only performed once, and not on every property access demand.

How to test

The following script will loop agains orders and print items / channel data :

$store    = $session->getMainStore();
$orders  = $store->getOrderApi()->getPage(['limit' => 10]);

foreach ($orders as $order) {
    print_r($order->getItems()->toArray());
    print_r($order->getChannel()->toArray());
}

[ronan-gloo]

@ddattee I've cleaned a bit the documentation to make it more readable

[ddattee]

Add var type in comments

[ddattee]

Maybe withItems would more accurate ?

[ronan-gloo]

with* are usually instance modifiers for immutable objects (check PSR-7 implementation).

[ddattee]

'...when NOT present...'

[ronan-gloo]

@ddattee review done