I am currently trying to retrieve some data from book search sites and populate a personal database with that data. My idea is to inject the necessary jQuery on the page, so that when I see a title I think I'd like to return to in future, I can then just click a cheeckbox, make necessary additional comments, which I then hope to submit by AJAX to a PHP script which then populates my MySQL database for me with the appropriate title.
Do look at this example for a library catalogue:
// for every book entry, append checkboxes
$('.document-frame').append('<p>Choose:?<input type="checkbox" class="Jcustom_c" /></p><p>Serendepity?:<input type="checkbox" class="Jserep" /></p><p>Include snippet?:<input type="checkbox" class="Jsnippet" /></p>');
// append a Submit button at the bottom of the page, and a blank div for feedback upon success in POST-ing the necessary data
$('#resultPage').append('<input id="Justin" class="Jcustom" type="submit"/><div id="Jfeedback"></div>');
// whenever my checkbox is checked, retrieve / "scrape" the necessary book data
$('.Jcustom_c').change(function() {
if ($(this).is(':checked'))
{
var title = $(this).parent().parent().find('.title a').text();
var author = $(this).parent().parent().find('.authors a').text();
var publishd = $(this).parent().parent().find('.publisher').text();
var status = $(this).parent().parent().find('.metadata .summary').text();
var img_link = $(this).parent().parent().find('img.artwork').attr("src")
// create an XML string from that data. Escape "<" and ">", otherwise when we append the string to the browser for feedback, the browser will not render them correctly.
var appended = '<div class="Jappended"><item><title>' + title + '</title><author>' + author + '</author><publisher_n_edn>' + publishd + '</publisher_n_edn><status>' + status + '</status><image>' + img_link + '</image><serep>N</serep></item></div>';
// show the string just below the book title. Hence if I "pick" the book from the catalogue, the XML string will show up to confirm my the fact that I "picked" it.
$(this).parent().parent().append(appended);
}
// if I uncheck the box, I remove the XML string
else {
$(this).parent().nextAll(".Jappended").remove(appended);
$(this).parent().prevAll(".Jappended").remove(appended);
}
});
And then I have the AJAX:
$('#Justin').click(function(e) {
e.preventDefault;
var string = "<itemset>";
$(".Jappended").each(function() {
var placeh = $(this).text();
string = string + placeh;
$('.results_container').append(string);
})
// these come from <textarea> boxes I append to the end of the page just before the Submit button. (Above, I did not include the jQuery to append these boxes.)
var odp = $("#odp").val()
var mre = $("#motivation_revisit").val()
var mra = $("#motivation_rationale").val()
var stu = $(".hdr_block h5 span").text()
var string = string + "<odpath>" + odp + "</odpath><stused>" + stu + "</stused><motivation><revisit>" + mre + "</revisit><rationale>" + mra + "</rationale></motivation></itemset>"
var post_var = { xml_string : string, source : "NUS" };
$.post('http://localhost:8888/db-ajax.php', post_var , function(data) {
$('#Jfeedback').html(data);
});
My problem is that I can't seem to get the AJAX to work: When I click on my Submit button, I do not see the output I would expect when I used the exact same jQuery on an HTML file I called from localhost. This, which I called using http://localhost:8888/some_html.html
worked:
<html>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js" ></script>
<script>
$(document).ready( function() {
...
$('#Justin').click(function(e) {
e.preventDefault;
var string = "<itemset>";
/*
$(".Jappended").each(function() {
var post_var = { xml_string : "hello", source : "NUS" };
$.post('http://localhost:8888/db-ajax.php', post_var , function(data) {
// if (data == "Success") {
$('#Jfeedback').html(data);
// }
});
});
});
</script>
<body>
...
</body>
</html>
db-ajax.php is simply:
echo "Success";
I have read this post: jQuery cannot retrieve data from localhost, which mentions something about "JavaScript cannot currently make direct requests cross-domain due to the Same-origin Policy". Is this the reason why my code didn't work on the external page? If yes, what can I do to make the code work, or what other approaches can I adopt to achieve the same goal? I have mutliple book search sites that I am working on, and many of these do not have an API where I can extract data directly from.
Thank you in advance.
P.S.: I've also tried the suggestion by CG_DEV on How to use type: "POST" in jsonp ajax call, which says that $.post can be done with jsonp, which is the data type to use for cross-domain AJAX. Result: On Firebug I do see the POST request being made. But my function callback is not fired, and firebug doesn't register a Response body when at least "Success" should be returned.