Amazon MWS: Accessing Array of Matching Products - php

Question

I am Working with MWS for the first time and hoping to create a program that uses the ListMatchingProducts request to average out the prices of every product that matches a query.
It should be a very simple program, but I am having trouble retrieving data.
First I make the call and get amazon's xml sheet, Then I convert the xml to an array.
Print_R shows that the array looks something like this:
Array ( [ListMatchingProductsResult] => Array ( [Products] => Array ( [Product] => Array ( [0] => Array ( [Identifiers] => Array ( [MarketplaceASIN] => Array ( [MarketplaceId] => ATVPDKIKX0DER [ASIN] => 0786866020 ) ) [AttributeSets] => Array ( [ItemAttributes] => Array ( [Author] => Array ( [0] => Stephen C. Lundin [1] => Harry Paul [2] => John Christensen ) [Binding] => Hardcover [Brand] => Hyperion [Color] => White [Creator] => Ken Blanchard [Edition] => 1 [Feature] => Great product! [ItemDimensions] => Array ( [Height] => 8.25 [Length] => 5.50 [Width] => 0.00 [Weight] => 0.54 ) [IsAdultProduct] => false [Label] => Hyperion [Languages] => Array ( [Language] => Array ( [0] => Array ( [Name] => english [Type] => Published ) [1] => Array ( [Name] => english [Type] => Original Language ) [2] => Array ( [Name] => english [Type] => Unknown ) ) ) [ListPrice] => Array ( **[Amount] => 21.00** [CurrencyCode] => USD ) [Manufacturer] => Hyperion [ManufacturerMaximumAge] => 1188.0 [ManufacturerMinimumAge] => 156.0 [NumberOfItems] => 1 [NumberOfPages] => 110 [PackageDimensions] => Array ( [Height] => 0.65 [Length] => 8.60 [Width] => 5.65 [Weight] => 0.58 ) [PackageQuantity] => 1 [PartNumber] => 9780786866021 [ProductGroup] => Book [ProductTypeName] => ABIS_BOOK [PublicationDate] => 2000-03-08 [Publisher] => Hyperion [ReleaseDate] => 2000-03-08 [SmallImage] => Array ( [URL] => http://ecx.images-amazon.com/images/I/51cHo55tbOL._SL75_.jpg [Height] => 75 [Width] => 47 ) [Studio] => Hyperion [Title] => Fish: A Proven Way to Boost Morale and Improve Results ) ) [Relationships] => Array ( ) [SalesRankings] => Array ( [SalesRank] => Array ( [0] => Array ( [ProductCategoryId] => book_display_on_website [Rank] => 4629 ) [1] => Array ( [ProductCategoryId] => 1043856 [Rank] => 2 ) [2] => Array ( [ProductCategoryId] => 2635 [Rank] => 7 ) [3] => Array ( [ProductCategoryId] => 2637 [Rank] => 18 ) ) ) ) [1] ...
I am trying to access the amount part of the array, as this is the price of the object. Eventually, I will need to access the amount of each product and so a loop will likely come into play, but right now i cannot even access one products sales amount.
Here is the code I have been trying
$value = $array->ListMatchingProductsResult->Products->Product[0]->ListPrice->Amount;
print_r($value);
And it is not working. Even calling print_r on $array->ListMatchingProductsResult is not printing an array.
Any help is greatly appreciated!
Thanks,
Matt

Answer 1

You are almost there. Whatever method you are using to convert the XML to a PHP array however, does just that: It creates an associative array of things, not an object. That is why you cannot access it through the ->element operator, but need to use array indexes ['element']
$value = $array['ListMatchingProductsResult']['Products']['Product'][0]['ListPrice']['Amount'];
If you're ever wondering why you're not getting something back, you can successily shorten above expresion until you do. So if a print_r(...) on above expression returns nothing, just remove one square bracket at a time from that print_r until you do get something back. You then know that the last bracket you removed was the culprit.
Array (
[ListMatchingProductsResult] => Array (
[Products] => Array (
[Product] => Array (
[0] => Array (
[Identifiers] => Array (
[MarketplaceASIN] => Array (
[MarketplaceId] => ATVPDKIKX0DER
[ASIN] => 0786866020
)
)
[AttributeSets] => Array (
[ItemAttributes] => Array (
[Author] => Array (
[0] => Stephen C. Lundin
[1] => Harry Paul
[2] => John Christensen
)
[Binding] => Hardcover
[Brand] => Hyperion
[Color] => White
[Creator] => Ken Blanchard
[Edition] => 1
[Feature] => Great product!
[ItemDimensions] => Array (
[Height] => 8.25
[Length] => 5.50
[Width] => 0.00
[Weight] => 0.54
)
[IsAdultProduct] => false
[Label] => Hyperion
[Languages] => Array (
[Language] => Array (
[0] => Array (
[Name] => english
[Type] => Published
)
[1] => Array (
[Name] => english
[Type] => Original Language
)
[2] => Array (
[Name] => english
[Type] => Unknown
)
)
)
[ListPrice] => Array (
[Amount] => 21.00
[CurrencyCode] => USD
)
[Manufacturer] => Hyperion
...
BTW, using <pre>...</pre> is helpful when trying to make sense of print_r() or var_dump().
P.S. You owe me a new space key.

Answer 2

Here is an sdk library that uses the ListMatchingProducts of Amazon MWS. You will be able to get the info in accessing info required.
https://github.com/choomz/amazon-mws-sdk/blob/master/search/src/MarketplaceWebServiceProducts/Samples/ListMatchingProductsSample.php
To show php errors have this set in your php.in
display_errors = On
You can also give this on top of the php script
ini_set('error_reporting', E_ALL);
ini_set('display_errors', 'On');