I am trying to read data from this API, but it is not working, I have an input box where I enter the isbn number and then get the data, using jsonp. Could you possibly help me in identifying where my error("Cannot read property 'title' of undefined") is?
function add(){
var isbn = parseInt($("#isbn").val());
var list = $("#list");
console.log(parseInt(isbn));
$.ajax({
url: "https://openlibrary.org/api/books?bibkeys=" + isbn + "&jscmd=details&callback=mycallback",
dataType: "jsonp",
success: function(isbn){
var infoUrl = isbn.info_url;
var thumbnailUrl = isbn.thumbnail_url;
var title = isbn.details.title;
var publishers = isbn.details.publishers;
var isbn13 = isbn.details.isbn_13;
console.log(isbn.info_url);
}
});
}
Open Library's API expects bibkeys
to be prefixed with their type and a colon, rather than just the number alone:
function add(){
var isbn = 'ISBN:' + $("#isbn").val();
// ...
The colon also means the value should be URL-encoded, which jQuery can do for you:
$.ajax({
url: "https://openlibrary.org/api/books?jscmd=details&callback=?",
data: { bidkeys: isbn },
dataType: "jsonp",
Then, the data it returns reuses the bibkeys
you provided as properties:
{ "ISBN:0123456789": { "info_url": ..., "details": { ... }, ... } }
To access the book's information, you'll have to first access this property:
success: function(data){
var bookInfo = data[isbn];
console.log(bookInfo.details.title);
// etc.
}
Example: https://jsfiddle.net/3p6s7051/
You can also retrieve the bibkey
from the object itself using Object.keys()
:
success: function (data) {
var bibkey = Object.keys(data)[0];
var bookInfo = data[bibkey];
console.log(bookInfo.details.title);
// ...
}
Note: You can use this to validate, since the request can be technically successful and not include any book information (ie no matches found):
success: function (data) { var bibkeys = Object.keys(data); if (bibkeys.length === 0) return showError('No books were found with the ISBN provided.'); // ...
Example: https://jsfiddle.net/q0aqys87/
I asked a professor, and this is how she told me to solve it:
function add(){
var isbn = parseInt($("#isbn").val());
var list = $("#list");
console.log(parseInt(isbn));
$.ajax({
url: "https://openlibrary.org/api/books?bibkeys=" + isbn + "&jscmd=details&callback=mycallback",
dataType: "jsonp",
success: function(data){
var thumb=data["ISBN:"+isbn+""].thumbnail_url;
....
}
});
}
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