xero PHP variable which starts with { - php

Question

A number of Xero accounts API samples have PHP variables which start with {
Example:
$invoices = {invoices:[{type: Invoice.TypeEnum.ACCREC, contact:{contactID:"00000000-0000-0000-000-000000000000"}, lineItems:[{ description:"Acme Tires", quantity:2.0, unitAmount:20.0, accountCode:"000", taxType:"NONE", lineAmount:40.0}], date:"2019-03-11", dueDate:"2018-12-10", reference:"Website Design", status: Invoice.StatusEnum.DRAFT}]};
I am struggling to understand how this can work. I am trying to use the API to create multiple invoices in the same call, I can do it fine in Postman so I know my code is OK.
I have tried following:
creating-an-invoice-using-oauth2-in-xero
Using the documents
But for some reason I just can't find a way to make it work.

Answer 1

All our SDKs and documentation is generated from our OpenAPI specs. Generating runnable code in our docs is our long term goal. In the interim, we needed to offer "some" generated docs, but the JSON payloads are not meant to be used.
We have created a sample app that demonstrates different endpoints and displays the code used to make the call.
https://github.com/XeroAPI/xero-php-oauth2-app
Here is the code you'll need to create an invoices
$result = $apiInstance->getContacts($xeroTenantId);
$contactId = $result->getContacts()[0]->getContactId();
$contact = new XeroAPI\XeroPHP\Models\Accounting\Contact;
$contact->setContactId($contactId);
$arr_invoices = [];
$invoice_1 = new XeroAPI\XeroPHP\Models\Accounting\Invoice;
$invoice_1->setReference('Ref-456')
->setDueDate(new DateTime('2019-12-10'))
->setContact($contact)
->setLineItems($lineitems)
->setStatus(XeroAPI\XeroPHP\Models\Accounting\Invoice::STATUS_AUTHORISED)
->setType(XeroAPI\XeroPHP\Models\Accounting\Invoice::TYPE_ACCPAY)
->setLineAmountTypes(\XeroAPI\XeroPHP\Models\Accounting\LineAmountTypes::EXCLUSIVE);
array_push($arr_invoices, $invoice_1);
$invoice_2 = new XeroAPI\XeroPHP\Models\Accounting\Invoice;
$invoice_2->setReference('Ref-123')
->setDueDate(new DateTime('2019-12-02'))
->setContact($contact)
->setLineItems($lineitems)
->setStatus(XeroAPI\XeroPHP\Models\Accounting\Invoice::STATUS_AUTHORISED)
->setType(XeroAPI\XeroPHP\Models\Accounting\Invoice::TYPE_ACCPAY)
->setLineAmountTypes(\XeroAPI\XeroPHP\Models\Accounting\LineAmountTypes::EXCLUSIVE);
array_push($arr_invoices, $invoice_2);
$invoices = new XeroAPI\XeroPHP\Models\Accounting\Invoices;
$invoices->setInvoices($arr_invoices);
$result = $apiInstance->createInvoices($xeroTenantId,$invoices);