1. The jQuery Divide
Rebecca Murphey • JSConf.eu • 25.09.2010
@rmurphey • rebeccamurphey.com
Wednesday, September 29, 2010

2. Wednesday, September 29, 2010

3. what this presentation covers
how jQuery’s popularity means newcomers
learn bad things
why I think this is worth talking about at
JSConf
what I think the larger JavaScript community
needs to do about it
Wednesday, September 29, 2010

4. We need you to
help us organize our
jQuery-based
application. It’s a
steaming pile of
unmaintainable
crap.
Wednesday, September 29, 2010

5. But we want to
keep using jQuery.
It’s just so easy!
And popular!
Wednesday, September 29, 2010

6. It’s almost guaranteed that the client will point
to jQuery’s popularity as a reason to keep using
it. It’s also a pretty fair bet what their code will
look like.
Wednesday, September 29, 2010

7. var toggleHistItems = function (selTabId) {
console.log('Selected Tab ID: ' + selTabId);
var curEl = $('#' + selTabId);
var bSLTabSelected = $('#slhis').is('[class=left selected]');
$('#divNoRecordMsg').hide();
switch (selTabId) {
case 'slhis':
$('tr[class^=fk]').show();
$('.cPriceRent').html('Foo/Bar');
rentalRateIsVisible(true);
$('#historySortButton').show();
//curEl.addClass('left');
if ($('#historySort1').is(':visible')) {
if ($('#fooLeaseHistory > tbody > tr[class^=fk]').length === 0) {
if (!$('#divAction1').is(':visible') && !$('#divRSAction1').is(':visible')) {
$('#divNoRecordMsg').html('There is no history at this time').show();
}
$('#historySortButton').hide();
$('#fooLeaseHistory').slideUp();
}
else {
$('#fooLeaseHistory').slideDown();
}
} else {
if ($('#listingDisplay > tbody > tr[class^=fk]').length === 0) {
if (!$('#divAction1').is(':visible') && !$('#divRSAction1').is(':visible')) {
$('#divNoRecordMsg').html('There is no history at this time').show();
}
$('#historySortButton').hide();
$('#listingDisplay').slideUp();
}
else {
$('#listingDisplay').slideDown();
}
}
break;
case 'shis':
rentalRateIsVisible(false);
$('#historySortButton').show();
Wednesday, September 29, 2010

8. Plus that way our
database guy can
still help us out
with the front end.
Wednesday, September 29, 2010

9. *headdesk*
Wednesday, September 29, 2010

10. “... it turns out that if you have absolutely
no idea what you’re doing in the language
you can still generally make things work.”
Douglas Crockford, Yahoo!
http://developer.yahoo.com/yui/theater/video.php?v=crockonjs-2
Wednesday, September 29, 2010

11. the morals of the story
perceived popularity & perceived ease of use
factor into library choice (duh)
people who don’t know JS write non-trivial JS
apps whether we like it or not
there’s a demand for answers to app org
questions
the people seeking these answers aren’t
necessarily dumb, just untrained in JS
Wednesday, September 29, 2010

12. jQuery meant we didn’t have to understand
this ...
Wednesday, September 29, 2010

13. var xmlhttp;
if (window.XMLHttpRequest) {
// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
} else {
// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.open("POST","ajax_test.asp",true);
xmlhttp.setRequestHeader("Content-type","application/x-www-
form-urlencoded");
xmlhttp.send("fname=Henry&lname=Ford");
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById("myDiv").innerHTML =
xmlhttp.responseText;
}
};
Wednesday, September 29, 2010

14. we could just write this ...
Wednesday, September 29, 2010

15. $.post(
'ajax_test.php',
{ fname : 'Henry', lname : 'Ford' },
function(resp) { $('#myDiv').html(resp); }
);
Wednesday, September 29, 2010

16. jQuery offers a really clear answer when we
need to build this ...
Wednesday, September 29, 2010

17. Wednesday, September 29, 2010

18. $(document).ready(function() {
$('#searchForm').submit(function(e) {
e.preventDefault();
var myVal = $(this).find('input:first').val();
$.ajax({
url : 'search.php',
data : { term : myVal },
dataType : 'json',
success : function(resp) {
var tpl = '<li><h2>%title</h2><p>%desc</p></li>';
$('#results').html(
$.map(resp.results, function(r) {
return tpl.replace('%title', r.title).replace('%desc', r.desc);
}).join('');
);
}
});
});
});
Wednesday, September 29, 2010

19. ... which is why we see this ...
Wednesday, September 29, 2010

20. Wednesday, September 29, 2010

21. Wednesday, September 29, 2010

22. But when it comes time to create this ...
Wednesday, September 29, 2010

23. Wednesday, September 29, 2010

24. ... it can be hard for the average jQuery
developer to see how they might get from the
rst version to the second without creating a
whole lot of spaghetti code.
Wednesday, September 29, 2010

25. It turns out jQuery’s DOM-centric patterns
are a fairly terrible way to think about
applications.
Wednesday, September 29, 2010

26. Applications require thinking in terms
of loosely coupled, DRYed out units of
functionality, designed to work with each
other without depending on each other.
Wednesday, September 29, 2010

27. require.def('views/Results', [], function() {
return Class.extend({
itemTemplate : '<li><h2>%title</h2><p>%desc</p></li>',
init : function(el) {
this.el = el;
$.subscribe('/search/results', $.proxy(this, '_showResults'));
},
_showResults : function(results) {
var tpl = this.itemTemplate,
html = $.map(results, function(r) {
return tpl
.replace('%title', r.title)
.replace('%desc', r.desc);
}).join('');
this.el.append(html);
}
});
});
Wednesday, September 29, 2010

28. require.def('views/Results', [], function() {
return Class.extend({
itemTemplate : '<li><h2>%title</h2><p>%desc</p></li>',
init : function(el) {
this.el = el;
$.subscribe('/search/results', $.proxy(this, '_showResults'));
},
_showResults : function(results) {
var tpl = this.itemTemplate,
html = $.map(results, function(r) {
return tpl
.replace('%title', r.title)
.replace('%desc', r.desc);
omg wtf is this???
}).join('');
this.el.append(html);
}
});
});
Wednesday, September 29, 2010

29. We shouldn’t scold; cartoon client man — and
the developers lured to JavaScript by jQuery —
don’t know what they don’t know.
Wednesday, September 29, 2010

30. Some people i’ve talked to think we or the
market should discourage these people from
writing code, but that ship has already sailed.
Wednesday, September 29, 2010

31. ey’re writing code whether we like it or not,
and it’s not good code.
Wednesday, September 29, 2010

32. is has actual effects on the perception of
JavaScript, and on our ability to do interesting
things with it.
Wednesday, September 29, 2010

33. In a nutshell, this is what these developers
need to learn:
Wednesday, September 29, 2010

34. JavaScript
jQuery
Wednesday, September 29, 2010

35. Companies need developers, and if bad ones
are all that’s available, they’ll hire them
anyway.
Wednesday, September 29, 2010

36. Wednesday, September 29, 2010

37. Aaron Newton from Cloudera wrote a post a
while back about how hard it is to nd “badass”
JavaScript developers.
Wednesday, September 29, 2010

38. e productive reaction to a post like that isn’t
to feel superior because you’re a badass
JavaScript developer.
Wednesday, September 29, 2010

39. e productive reaction is to gure out how to
x it.
Wednesday, September 29, 2010

40. jQuery’s ease has brought us legions of
developers who think of an application like
this: disparate pieces with few organizing
principles; components that are fun but aren’t
made to work together.
Wednesday, September 29, 2010

41. We need to turn them into developers who think
of applications like this.
Wednesday, September 29, 2010

42. five things
to think about
Wednesday, September 29, 2010

43. #1
popularity contests are stupid
Wednesday, September 29, 2010

44. Making decisions based on this graph ...
Wednesday, September 29, 2010

45. Wednesday, September 29, 2010

46. ... makes as much sense as making decisions
based on this graph ...
Wednesday, September 29, 2010

47. Wednesday, September 29, 2010

48. We have to be intellectually honest when we
discuss library pros & cons — and vigorous
in correcting those who are not.
http://xpandapopx.deviantart.com/art/The-Prideful-Hypocrite-68848153
Wednesday, September 29, 2010

49. #2
choose tools, not APIs
Wednesday, September 29, 2010

50. // YUI3
var parent = Y.Node.create('<div/>'),
child = Y.Node.create('<p>foo</p>');
child.on('click', fn);
parent.appendChild(child);
// Dojo
var parent = dojo.create('div'),
child = dojo.create('p', { innerHTML : 'foo' });
dojo.connect(child, 'click', fn);
dojo.place(child, parent);
// jQuery
var parent = $('<div/>');
$('<p>foo</p>')
.click(fn)
.appendTo(parent);
Wednesday, September 29, 2010

51. $(document).ready(function() {
$('#searchForm').submit(function(e) {
e.preventDefault();
var myVal = $(this).find('input:first').val();
$.ajax({
url : 'search.php',
data : { term : myVal },
dataType : 'json',
success : function(resp) {
var tpl = '<li><h2>%title</h2><p>%desc</p></li>';
$('#results').html(
$.map(resp.results, function(r) {
return tpl.replace('%title', r.title).replace('%desc', r.desc);
}).join('');
);
}
});
});
});
Wednesday, September 29, 2010

52. (function(d, $) {
d.ready(function() {
d.connect('searchForm', 'submit', function(e) {
e.preventDefault();
var myVal = $('input', this)[0].value;
d.xhrGet({
url : 'search.php',
content : { term : myVal },
handleAs : 'json',
load : function(resp) {
var tpl = '<li><h2>%title</h2><p>%desc</p></li>';
d.byId('results').innerHTML = d.map(resp.results, function(r) {
return tpl.replace('%title', r.title).replace('%desc', r.desc);
}).join('');
}
})
});
});
})(dojo, dojo.query);
Wednesday, September 29, 2010

53. #3
understanding the problem
is key to determining the solution
Wednesday, September 29, 2010

54. Decision-makers need help to make actual
decisions ... and understand their consequences.
Wednesday, September 29, 2010

55. understand the project
application vs. website?
team skills: dedicated F2E?
team size & turnover?
project lifecycle: long-term, evolving product?
service-oriented back-end?
Wednesday, September 29, 2010

56. assess the application’s needs
code & le organization?
dependency management & build tools?
templating & templated widgets?
data abstractions & binding?
a11y, i18n & l10n?
Wednesday, September 29, 2010

57. then and only then, choose your tools
features that address the application’s needs?
active development?
active community?
documentation & resources?
institutional backing?
Wednesday, September 29, 2010

58. #4
RTFM can’t be our go-to answer
Wednesday, September 29, 2010

59. “[It’s] a difficult time to learn to be a JavaScript
ninja, or even a JavaScript street beggar. Good
resources for getting beyond the very
basics are hard to nd, documentation is
sparse or wrong, and a snippet of code that
may have been viable last year is now an anti-
pattern.”
http://www.clientcide.com/deep-thoughts/why-its-a-good-idea-to-be-a-javascript-developer-and-what-it-takes-to-be-one/#comment-32703
Wednesday, September 29, 2010

60. #5
sharing what we know
is as important as
making new things
Wednesday, September 29, 2010

61. Wednesday, September 29, 2010

62. rebeccamurphey.com • blog.rebeccamurphey.com • @rmurphey
anks, in guilt-free alphabetical order, to: Tim Caswell, John Hann, Peter Higgins, Tom Hughes-
Croucher, Paul Irish, Brian LeRoux, Roger Raymond, Alex Sexton, Colin Snover, Adam Sontag, Chris
Williams, and to everyone who listened to me formulate my thoughts.
Wednesday, September 29, 2010