On Jul 28, 1:10*am, Karl Tikjøb Krukow <karl.kru...@gmail.com> wrote:
> On 28/07/10 00.01, David Mark wrote:
>
>
>
>
>
> > On Jul 27, 2:46 pm, Karl Tikjøb Krukow<karl.kru...@gmail.com> *wrote:
> >> Karl Tikjøb Krukow wrote:
> >>> Richard Cornford wrote:
> >> [snip]
> >>>> The "Potential cons" list:-
>
> >>>> - Does not mention that the libraries are rarely actually cross-
> >>>> browser (but merely support a limited set of brewers, so are actually
> >>>> little more than an elaboration of the "both browsers" scripts from
> >>>> the end of the last century).
>
> >>> Ok, I've added a bullet "Rarely supports more than a handfull of browsers"
>
> >> [snip]
>
> >> Trade-off: if and what library to use
> >> Potential pros:
> >> - Responsibility of handling most cross-browser concerns are pushed to
> >> the library developers
>
> > That's virtually never a pro. *Experienced developers know that
> > complicated, monolithic do-everything-for-everybody scripts are
> > inappropriate for a language that must be downloaded, runs in a single
> > thread and must face many disparate environments. *It's generally
> > folly to try and the inexperienced are typically the ones who do.
>
> > General-purpose JS libraries and frameworks are also the most
> > challenging of browser scripting projects, so combined with mostly B
> > Team contributors, the results are predictably disastrous.
>
> > Furthermore, none of the "majors" is capable of supporting progressive
> > enhancement in any meaningful way. *The calling applications have no
> > idea which methods will work and which will fall on their face. *This
> > precludes any possibility of graceful degradation in hostile or
> > limited environments.
>
> It was written as a "potential pro"
Fair enough.
>
> In an ideal scenario, pushing this responsibility to an experienced
> cross-browser developer would be a pro.
Absolutely, but as Richard mentioned, the "majors" are not cross-
browser in any sense of the term. I'd be careful with the term "pro"
as well. Just because somebody somewhere may have paid for the
services of a library author, doesn't make them proficient (only
professional).
> Obviously, when it is not
> handled appropriately, it becomes a con:
And, the sad story is that it has not been handled appropriately by
the "pros" on the other end as they haven't really done what they set
out to do.
"You may not be happy with all
> the solutions that library developers have chosen, nor consistency of
> all APIs".
True enough. Of course, they may not be experienced enough to make
wise judgements in such matters. In other words, they may be happy as
clams with something like jQuery and not realize that they are
standing on the shoulders of midgets.
>
>
>
> > AFAIK, there is but one (comprehensive) GP library that has come close
> > to delivering a truly cross-browser (and largely maintenance-free)
> > experience, while supporting progressive enhancement.
>
> >http://www.cinsoft.net/
>
> > That being said, I don't recommend telling your students to use it.
> > They need to learn how to write browser scripts before they start
> > trying to borrow code from others.
>
> Yes, I mention "My Library" as a notable exception (a long with Fork and
> APE, but they don't look as comprehensive nor maintained).
Yes, I think Fork "died" years ago (though may well still work as it
is a cross-browser script). APE has never amounted to much AFAIK.
>
> Hopefully, by the end of the course they will be able to comprehend why
> code such as "My Library" is written as it is.
That would be helpful.
> Hopefully they will
> understand the general principles and techniques, albeit they will not
> have extensive knowledge of various bugs and quirks of particular
> browsers.
Here's the most important point: it doesn't require vast knowledge of
browser quirks to be successful. After all, how could I have known
what IE8 or IE9 would look like back in 2007?
It's about understanding the underlying abstractions, proper feature
detection and testing patterns and solving problems. Memorization (or
prognostication) rarely enter into it.
Granted, when attempting to solve every problem related to browser
scripting for everybody, there will be times when observation of
quirks is required. But it is what you do with those observations is
what determines how far you will go in this business.
> I won't recommend any particular library: hopefully they will
> be able to make an informed decision on their own.
Be sure to mention the possibility of *not* using a GP library.
That's also an important concept (and is not tantamount to "writing
everything from scratch").
>
> At least that is the goal.
Hey, I salute you for your efforts. The world needs more competent JS
developers. It starts with the kids.
>
>
>
> >> - Common utility functions and reusable components
>
> >> - One place to go for documentation, and a single community
>
> > That's not necessarily a pro either. *There are lots of places to go
> > to find information about JS and browser scripting in general (granted
> > most of them are very bad). *There is but one jQuery documentation
> > site.
>
> > As for community. *As Richard noted, the "support" communities are
> > mostly the blind leading the blind.
>
> Again, a "potential" pro. At the course, I will discuss the warning that
> Richard and yourself are giving.
Good deal.
>
> > Furthermore, it's not always true that there is a single point of
> > contact. *Many of these efforts get fragmented over the years (see
> > Dojo and Ext JS), even so much as to break their Google search results
> > by changing domain names (Ext JS and Dojo each did that *twice* at
> > least).
>
> While I agree that it is not always true, usually it is a single (or a
> few) points of contact. I think I will keep this bullet.
Yes, but more importantly, who are they contacting? Programmers or
pattern arrangers?
>
>
>
> >> Potential cons:
> >> - You may not be happy with all the solutions that library developers
> >> have chosen, nor consistency of all APIs
>
> > That's an understatement of a disclaimer.
>
> Yes, I am deliberately not using too strong statements in this
> presentation.
Fair enough.
>
> [snip]
>
> >> - Browser detection requires continous maintainance/upgrades
>
> > And it may well fail *today* (in environments unknown to or unobserved
> > by) the developers. *Furthermore, the "upgrades" invariably break
> > yesterday's browsers, leading them to be lopped off the "supported"
> > list. *Of course, end-users don't read such lists and cannot be
> > expected to upgrade their browsers in perfect step with the library
> > developers.
>
> I will include this point explicitly.
Glad to hear it.
>
>
>
> >> - Monolithic/non-modular libraries will inevitably contain many features
> >> that you won't use
>
> > And must be "upgraded" in one go, requiring a reboot of regression
> > testing. *It's a nightmare in practice (again Dojo, Ext JS and the
> > like are the most extreme examples).
>
> Do you mean as opposed to a modular library where you would be able to
> upgrade a particular module, keeping other modules in an older version?
>
> That is a good point.
Yes. And it is important to realize that they all claim to be
modular, but (particularly in the case of Dojo and Ext JS) it's
usually all smoke due to interdependencies. For example, Dojo's XHR
module requires its (highly dubious) query module. What does XHR have
to do with CSS selector queries?
>
>
>
>
>
> >> - Libraries will inevitably not contain all you need.
>
> > No question there. *JQuery has never featured anything that I need
> > (and likely never will). *In fact, it could be argued that a 70K CSS
> > selector query engine that disagrees with its own QSA shim is a pig in
> > a poke for anybody these days. *There really are no valid arguments
> > for it. *All I ever hear are generalizations like "I use it as a
> > tool".
>
> >> Extensibility is
> >> useful.
>
> > Extensibility for JS libraries typically involves augmenting
> > "namespace" objects. *You can add properties to objects in any script,
> > so any script can be considered extensible in this way. *Granted, some
> > take it a step further with additional syntactic sugar, but rarely to
> > any real positive effect. *If anything, it encourages "plug-in"
> > authors who really shouldn't be writing JS in the first place (let
> > alone extensions for widely used libraries).
>
> I guess extensibility and customization is only relevant for "widget"
> libraries.
Yes, it's more relevant for those. And note that the "widget"
frameworks are often castles built on top of swamps. In other words,
they are the results of developers getting way ahead of themselves. I
can't name one such framework that is not completely execrable. Dojo,
YUI, Ext JS, Cappuccino, SproutCore, qooxdoo, etc. are all ill-advised
and unsuccessful attempts to make every control look the same in every
browser and chop off the browser's built-in layout mechanisms to be
replaced slowly and painfully with single-threaded scripts that fail
miserably (when compared with what they sought to replace) even in
their "supported" browsers. See Richard's comments about qooxdoo's
layout and widget scripts in a recent thread.
>
> The notion of extensibility that you consider is a property of the
> language itself. It is often not sufficient to be practical: I think the
> widgets should be designed with the mindset that the user should be able
> to easily change certain properties, provided that they still satisfy
> the same contract of the widget API.
Certainly. Unfortunately, the majors all go way too far with this,
often requiring a half-dozen levels of inheritance and tons of nested
DIV's to create the simplest of controls. As a result, they are slow,
bloated and inaccessible in numerous ways (when compared with what
they sought to replace) And whenever HTML5 finally gets here (and is
widely implemented), all of that crap will end up on history's scrap
heap anyway.
>
> But I guess it is really just a question of how well-designed it is: if
> well designed, extensibility and customization will probably follow.
Well, even a poor design can allow for massive customization.
>
>
>
>
>
> >> Advice on libraries
>
> >> * Consider your context
> >> * * *- General web vs. intranet.
> >> * * *- Accessibility requirements?
> >> * * *- Constrained devices? Unknown devices?
> >> * * *- App-in-a-page or hyper-text document? In between?
>
> >> * Be aware of the costs and benefits of using a particular library or not
> >> * * *- Make an informed decision
> >> * * *- Don't include a library “by default”
> >> * * *- If you choose to use one, consider which one to use basedon
> >> context: Don't decide by “what is hot” or “what I know”
>
> > Those are good points, but you need more.
>
> Would you mind helping me with what additional points I need?
I wouldn't mind at all. Perhaps tomorrow.
(unless you mean the points discussed in the present post).
I mean those, but certainly there are more.