On 2014-04-30 17:04, Adam D. Ruppe wrote:
I like implementing things myself :P
That's the question I dread most at meetings now: "is there a gem for
this?" idk, in the time it takes to search for and evaluate third party
code, I could have just written it myself. Especially since libraries
almost always need some kind of customization for our specific case anyway!
I don't agree with this.
A big difference though is the compiler helps you a lot in D. In Ruby,
for example, the main reason we use the unit tests (so far) is to help
ensure consistency after refactoring something. It catchings things like
a renaming we missed, or a removed method still in use.
Then you're not using unit tests correctly ;)
In D, you just recompile and those things are found almost instantly
without needing to actually run any code.
Yeah, sometimes it would be nice with static typing.
They deliberately avoid the most important parts of a relational database:
http://guides.rubyonrails.org/migrations.html
"The Active Record way claims that intelligence belongs in your models,
not in the database. As such, features such as triggers or foreign key
constraints, which push some of that intelligence back into the
database, are not heavily used."
I don't really agree with that. Although I'm not a fan of store
procedures/functions in the database. But I don't mind foreign key
constraints. We used that at my previous work. Via a gem :)
ORM is something I only like in very small quantities, but ActiveRecord
uses it for *everything*, well, except for the things it doesn't even
support.
The problem here is one of encapsulation and of correctness. If
something bypasses the model - which is required for tasks the library
doesn't even support and also likely to happen if there's a second app
using the data - all kinds of stuff can get in there that is bad.
You also have problems like race conditions:
account = BankAccount.find(1)
account.balance -= 10
account.save!
I think most Rails application are run single threaded. But with
multiple processes instead.
What if two of those run concurrently? I searched the web quickly for
this and haven't found a good answer yet...
Then, with referential integrity, the docs suggest DIY or getting some
third party gem, because their godawful library doesn't really support
it. The best it does is offer you a square wheel with the dependent
thing. Stupid stupid stupid.
All libraries have positive and negative sides.
idk, I use my database.d which has a little bit of overlap with what
active record does, but since I generally see ORM as being a nasty
anti-pattern and horribly leaky abstraction, I didn't go far with it.
Using a random D module for this doesn't feel very comfortable, no
offense. No documentation, no way to find examples and so on.
There's really nothing to fear with writing SQL, except the cases where
the language sucks.
ActiveRecord will hide all the ugliness of SQL. Properly escape values,
to type conversions, time zone conversions and so on. It's also database
independent.
(UPDATE and INSERT being so different, and the
solutions being different for the various vendors, ugh. That's why I
made my DataObject, it gathers the changes together then issues one of
those commands. It can also be gotten from a query, making it a kind of
simple active record:
auto obj = mysql.queryDataObject("select * from foo limit 1").front;
obj.whatever = "something";
obj.commitChanges(); // calls UPDATE foo SET whatever='something' WHERE
id = ?
which also works on joined queries on MySQL btw and offers easy support
for multiple primary keys or ones not named "id" (as an argument to
commitChanges), something active record as far as i can tell doesn't
even try to do, but it doesn't try to fetch child objects or anything
like that.
I have considered adding child object fetching, but I don't really see
the need, it is easy to write a method that does that if you want to.)
I prefer HAML (similar to Jade in vibe.d) but I don't think it's that
bad. What do you use?
The ruby thing looks like this <span class="foo"><%= @some_value %></span>.
For my D stuff, I have two options:
1) create the HTML right in D using dom.d. I like to use this for
objects that know how to format themselves and output strictly semantic
XML/HTML. The visual styling is then done with CSS. This works better
than you might expect!
Are you using some kind of proxy for this or are you pushing back the
view layer to the model?
2) web.d also has a fairly simple replacement system too:
<span class="foo">{$some_value}</span>
it also supports inserting partials
<div html-from="{$dynamic_html}"></div> or <include partial="foo" />,
though the include thing takes a wee bit of helper code from the app
because it needs to find the html somewhere.
Well, that's the same as in Rails. The HAML version would be:
<div html-from="#{@dynamic_html}"></div> or = render "foo". In Rails the
partial is just a template prefixed with an underscore. It fill find it
relative to the controller's view directory.
And the variable replacement can be piped: {$some_count|plural user
users} for example, which is kinda cool.
I'm not sure I understand this piping.
It does NOT support intertwined code. Other things are done with
attributes, such as class="if-logged-in" or <ul from="data_thing" />
(infinitely extensible with the server-side DOM).
What do you mean with "intertwined code"?
It looks like this
root "home#index"
get "/users/login", to: "users#login"
namespace :admin do
resources :users do
resources :children
end
end
and so on. It isn't awful (especially now that I get what they mean by
"resources"), but my web.d rarely uses explicit routing at all, it
figures it out automatically by the names, protection level, and types
of child members.
In Rails that would be:
match ":controller(/:action(/:id))"
So "/foo/bar/1" would route to "bar" action in the FooController with
"1" assigned as the "id" parameter in "params". Only works with public
methods. I really hate this. It quickly becomes a big mess.
You can also do a catch all route:
match "*path" => "home#page_not_found"
Responding with json, xml, and html Just Work with web.d, it figures it
out from the static type of the function return value.
In my experience it's rarely so easy. Most of the time I need to do some
customization of the format anyway so the built-in formatting isn't
suitable.
Yes, obviously that's some of it, but there's other things that I don't
expect to change, especially things like runtime errors for what the D
compiler would catch.
Yes, sure.
i love that, different strokes i guess.
I don't mind it but sometimes I just want to get some work done. I mean,
I've started out (or planed to) with some project in D but then I needed
to create all the support libraries and tools so I've almost forgot what
I was going to do in the first place.
I want to use Sass, CoffeeScript and HAML. But I don't want to write
three compilers just to do some web development.
--
/Jacob Carlborg
