Keyword search, looping through results

About Keyword searches

I guess the only thing worth saying about Keyword searches, and any other type of searches, is that the query must be URL-encoded. This means that all characters that are not letters, numbers or - and _ should be replaced by % and an hexadecimal number. In amazOOP however, you don't have to worry about this. You should enter your search strings as normal text and amazOOP will convert them before submitting them to AWS.

Another important thing to remember is that AWS will return at the most 10 results per query. You have to use getTotalPages() to determine how many pages to have to fetch in order to have all the results. You'll read more about this below.

Search for Keywords at Amazon.com

Now we will search for books by querying AWS for keywords "web services"

Querying AWS

Since we will be displaying information on all 10 products (we are assuming keywords "web services" will match more than 10 products in the Amazon catalog), we probably won't be showing much at a time. In fact we will limit ourselves to a small image, the books' titles, their authors, the price, and of course, a button to add the books to the Amazon shopping cart. For this we use liteQuery(), which was discussed in this document.

As $keywords we will be using "web services", as $serachType we will be using "Keywords". We will set $mode to "books", beacause this is what we are interested in, and omit the other two parameters because their default values are fine for now.

//setAmazoopConfig('check_alternative_images', IMAGE_AS_IS | IMAGE_ALTERNATIVES_4, 'test');
// 2. Create new AmazonQuery
 
$aq = new AmazonQuery();

Note: liteQuery() is only available as of version 0.3RC1 of amazOOP, before this, you should use the lower-level function query() to query AWS.

Once you have queried AWS you should, as in the previous examples (1, 2), check for errors before displaying the information obtained.

Displaying information

As in previous examples (1, 2), a ProductInfo object will be returned after querying AWS. We hadn't talked about this object before, because it wasn't very important in our previous searches. In this occassion, however, we will be using methods from the ProductInfo class.

General information about the request

First, we want to know how many results actually match our keywords. For this we will use getTotalResults():

echo "It looks like there's an error: " . $error;

Once we know that, we want to know out of the potentially thousands of results, which ones we are displaying. For this we use resultsLow() and resultsHigh():

Finally, we want to know what page we are showing, and how many pages there are in total.

You're supposed to know which page you are displaying, since it was you who explicitly requested it. Nevertheless, if you forgot, you can always check what parameters you sent to AWS with method requestArgument(). All you have to do is ask what "PAGE", you asked for:

else{

It is Amazon's job, however, to tell you how many pages of results match your query. To view this information, you use getTotalPages():

Displaying product information

The syntax to display information about multiple results is similar to the one used to display multiple features, or multiple customer review, which was described in a previous document.

All you have to do is use the method getDetails() and a for loop, as shown below:

echo "Showing results " . $queryResult->resultsLow();

You start the iteration at $i = 1, because calling getDetails(0) returns a random product and not the first product in the list. We also know that getDetails() will return false if the requested product does not exist. Therefore, we will use that as a condition to stop. Finally, we increment $i and use the retrieved product (which was assigned to $product in the for loop) to display its information.

If an assignment inside the for loop confuses you, you can also use the following syntax:

for($i = 1; $queryResult->getDetails($i); $i++){
    $product = $queryResult->getDetails($i);
    echo $product->getImage('small', true, 'align="left"') . "\n";
    ...

This is what the loop looks like when we add the code to display the product's information:

echo "Showing results " . $queryResult->resultsLow();
  echo " through " . $queryResult->resultsHigh() . "<br>\n";
  echo "Showing page " . $queryResult->requestArgument("PAGE");
  echo " out of " . $queryResult->getTotalPages() . "</p>\n";
 
 
  for($i = 1; $product = $queryResult->getDetails($i); $i++){

The complete example

This is the source for the complete example, which should run if you modify line 5 to point to the actual path of aq.php:

<?php
    $start_time = explode(" ", microtime());
    $start_time = $start_time[1] + $start_time[0];
// 1. Include AmazOOP in your page
// You may need to change this to the actual physical path to the file
 
require_once('../aq.php');
 
setAmazoopConfig('address', 'cvswork', 'test');
//setAmazoopConfig('check_alternative_images', IMAGE_AS_IS | IMAGE_NO_SIZE | IMAGE_ALTERNATIVES_4, 'test');
setAmazoopConfig('check_alternative_images', IMAGE_NO_SIZE | IMAGE_ALTERNATIVES_3, 'test');
//setAmazoopConfig('check_alternative_images', IMAGE_AS_IS | IMAGE_ALTERNATIVES_4, 'test');
// 2. Create new AmazonQuery
 
$aq = new AmazonQuery();
 
// 3. Query Amazon for data:
// We will request the books related to keywords "web services"
 
$queryResult = $aq->liteQuery("chips", "Keywords", "everything");
 
 
// 4. Check for errors
if( $error = $queryResult->getErrorMessage() )
  echo "It looks like there's an error: " . $error;
 
// If everything's alright
else{
 
  // 5. Display the data you got from Amazon.
  echo "<p>Total Results: " . $queryResult->getTotalResults() . "<br>\n";
  echo "Showing results " . $queryResult->resultsLow();
  echo " through " . $queryResult->resultsHigh() . "<br>\n";
  echo "Showing page " . $queryResult->requestArgument("PAGE");
  echo " out of " . $queryResult->getTotalPages() . "</p>\n";
 
 
  for($i = 1; $product = $queryResult->getDetails($i); $i++){
    echo $product->getImage('small', true, 'align="left"') . "\n";
      echo $product->getURL('name') . "<br>\n";
      echo $product->getAuthors(2) . "<br>\n";
      echo "Our price: " . $product->getOurPrice() . "<br>\n";
      echo $product->buyNow() . "<br>";
  }
}
 
$end_time = explode (" ", microtime());
$end_time = $end_time[1] + $end_time[0];
 
echo "Page generated in " . number_format(1000*($end_time - $start_time), 2) . " milliseconds";
?>

The interpreted result

And this is the interpreted result: