Post by Jacob Carlborg via Digitalmars-dI think one of the great things about Rails and Ruby is all the
libraries and plugins that are available. If I want to do
something, in RoR there's a big chance there's already a
library for that. In D, there's a big chance I need to
implement it myself.
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!
There's a few exceptions where something is hard to write, but
most things just aren't that hard.
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.
In D, you just recompile and those things are found almost
instantly without needing to actually run any code.
Post by Jacob Carlborg via Digitalmars-dHow do you mean? It just adds an object oriented layer on top
of it.
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."
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!
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.
When you actually use the database as it is intended, it takes
care of these things for you with very easy syntax that works
across business logic languages. Nothing new to learn there.
Post by Jacob Carlborg via Digitalmars-dBTW, what should I use in D. I need a library that is database
independent and I don't want to write SQL for the common use
cases?
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.
There's really nothing to fear with writing SQL, except the cases
where the language sucks. (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.)
Post by Jacob Carlborg via Digitalmars-dI 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!
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.
And the variable replacement can be piped: {$some_count|plural
user users} for example, which is kinda cool.
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).
Post by Jacob Carlborg via Digitalmars-dI don't know how you do you're routing but the first thing I do
when generating a new Rails application is to remove the
default routing. The default routing opens every public method
in a controller to be a routing end point. It's a complete mess.
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.
Post by Jacob Carlborg via Digitalmars-dThere's a plugin [1] for Rails for generating a form based on a
type. I don't understand how anyone can manage without that.
thx, I'll take a gander.
Post by Jacob Carlborg via Digitalmars-dIt can automatically respond in a couple of formats as well. By
default JSON, XML and Erb template. The most basic example will
Responding with json, xml, and html Just Work with web.d, it
figures it out from the static type of the function return value.
Post by Jacob Carlborg via Digitalmars-dYou don't think that's because you're used D for quite a while
and developed your own web framework. Compared to Rails where
you're completely new.
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.
I had to rename a thing last night. Took two hours to do the db
migrations and then rename the classes and update all the files.
I'm still not completely sure I did it right too! I've done
similar things in D in about 5 minutes, the compiler catches
everything so I have confidence.
Post by Jacob Carlborg via Digitalmars-dThe biggest problem I have with D is have to do everything
myself. I'm getting a bit tired of that.
i love that, different strokes i guess.