Support both ISBN-10 and ISBN-13?

[seekshiva]

The 13-digit ISBN checksum has been in use since 1st Jan 2007. Online retailers display both the 10 and 13 digit checksum about a book in the book info page.

Eg: http://www.flipkart.com/data-computer-communications-8/p/itmczymgxfv6unr2?pid=9788131715369&cmpid=content_book_8965229628_gmc_pla&tgi=sem,1,G,9226359,g,search,,30163692860,1o2,,,c,,,,,,,&gclid=CM-N_eWs_rsCFYJU4godYAgA9g

Search in the page for "ISBN"

Should we create separate attribute in the book model for isbn-10 and isbn-13 ?

[nobelium]

ISBN 13 is just an extension of ISBN 10. We need not store ISBN 13 for a book. ISBN 13 can be calculated from ISBN 10

function isbn10ToIsbn13(isbn10) {
    isbn13 = "978" + isbn10;
    return isbn13.substr(0, isbn13.length-1) + getIsbn13CheckSum(isbn13);
}

We can also check if the ISBN is valid. Refer wiki for more info http://en.wikipedia.org/wiki/International_Standard_Book_Number

[seekshiva]

You can't find ISBN 10 checksum from ISBN 13. It s not backward compatible.

All new books are only given an ISBN 13 checksum. Apart from amazon and flipkart, other booksellers probably only display ISBN 10 checksums. The outdated software used in book shops also probably only support the 10-digit checksum. Students will not be able to look up books from these places if we only show the 13-digit checksum.

We have to support both checksums:

• 10-digit because students will need it to look up books in most places other than flipkart/amazon
• 13-digit because new books don't have a 10-digit counterpart

[nobelium]

We will only store ISBN 10. ISBN 13 can be found from ISBN 10 while rendering the page. Both can be displayed. Calculation checksum for both is not an issue.

[nobelium]

Pull request #104 closes this.