John Miedema

OpenBook Plugin: Grabbing the Book Data

29 May 2008 2 Comments

This entry is part 6 of 12 in the series Building OpenBook

Last time, I pulled the book data from OpenLibrary into PHP so that I could start programming it. The data is fairly extensive but I just want a few fields, as per the requirements: author, book title, and publisher. Ideally, I would like to get a book cover image too — more on that later.

I have pulled all the data into a single variable, $bookdata. It may look a little confusing, but the good folks at OpenLibrary have put it in a standard format, JSON (JavaScript Object Notation). This means I can safely parse the data. But life gets even easier. PHP version 5 comes with a JSON library that makes extracting data very easy. My web server (netfirms.ca) uses PHP 4 by default, but a small switch in my website’s control panel upgraded it to PHP 5.

The fields I want are in the “results” section of the $bookdata variable, so I use the JSON library to extract the results, like so:

$obj = json_decode($bookdata );
$result = $obj->{‘result’};

Next I grab the title (and subtitle), authors (under “contributions”), and publisher.

$title = $result ->{‘title’};
$subtitle = $result ->{’subtitle’};
$contributions= $result ->{‘contributions’};
$publishers= $result ->{‘publishers’};

Notice there is no URL for the cover image in the results. I was disappointed about that. Very much so, because I want a cover image to display on the posts. I have a plan to resolve this, but that deserves a post all to itself, and that will have to wait a little while because I have to do some research and proof-of-concept work. Once I have that sorted, I will format all the book data into its final HTML. For now I will just print them out, using the PHP echo:

echo “Title: “.$title;
echo “Subtitle: “.$subtitle;
echo “Author 1: “.$contributions[0];
echo “Author 2: “.$contributions[1];
echo “Publisher: “.$publishers[0];

When I wrap everything so far in PHP tags, the code is processed, and the results are displayed like:

Title: Revolting librarians redux
Subtitle: radical librarians speak out
Author 1: Roberto, Katia, 1975-
Author 2: West, Jessamyn, 1968-
Publisher: McFarland & Co.

I’ll be back after I get the book cover image matter sorted.

Index

Series Navigation«OpenBook Plugin: Coding in PHPOpenBook Plugin: Let There Be Cover Images!»

2 Comments »

Paul Rodriguez said:

Two small suggestions. If you write

echo “Title:” . ucwords($title);

It will return with proper capitalization:

Title: Revolting Librarians Redux

For the cover, OpenLibrary seems to use a fairly consistent system. I presume they will eventually integrate the cover URLs into their API, but until then, you could use:

$full_cover_url = “http://openlibrary.org/static/bookcovers/full/” . substr($result->{‘isbn_10′}, 0, 1} . “/” . substr($result->{‘isbn-10′}, 1, 1) . “/” . $result->{‘isbn_10′} . “.jpg”;
$thumb_cover_url = “http://openlibrary.org/static/bookcovers/thumb/” . substr($result->{‘isbn_10′}, 0, 1} . “/” . substr($result->{‘isbn-10′}, 1, 1) . “/” . $result->{‘isbn_10′} . “.jpg”;
echo “Full cover: “;
echo “Thumbnail cover: “;

# 29 May 2008 at 3:11 pm

John said:

Paul, I knew there was a good reason for blogging this process. I will definitely use your first suggestion, and I will have a good look at the second. OL is working on a cover image API, but till then your suggestion might work. Much appreciated.

# 29 May 2008 at 4:14 pm