Very clear explanation, thanks. A couple of questions follow (see below)...Right, that is on the dancer side. What is it going to be on the browser side? In my Javascript, I have
Flavio Poletti wrote:
I don't know much about REST, but the base should be that you have to
map the thing you want to do upon HTTP methods, which have a
well-defined semantics. In particular, if you want to...
... get some data, without having collateral effects on the data => use
HTTP GET
... modify some existing data => use HTTP POST
... add some data => use HTTP PUT
... delete some data => use HTTP DELETE
Dancer happens to support the four methods via the usual route
definition approach, with lowercase functions for each HTTP METHOD,
except that (HTTP) DELETE is called "del" (this is due to the fact that
"delete" is a built-in keyword in Perl and it's better to leave it alone).
So, if you want to delete something under the REST umbrella, you're
supposed to use Dancer's "del" instead of "get":
del '/:foo_id' => sub { ... }
$.ajax({
url : "http://server/foo/" + foo_id,
type : "GET",
data : "",
dataType: "json",
error : function() { alert("Error loading html document"); },
success : function(data) {
alert("Foo " + foo_id + " was successfully deleted");
}
});
So, from the browser's perspective, I am still sending an http get request, correct? Or, should that "type:" above really be a "DELETE" instead of a "GET"?
Of course, if that is the case, then, from the browser's perspective, there is no difference between a get request that deletes and a get request that really gets.
This is a bit worrisome as I have to get my ordering really correct. I guess I could first have all the routes that are identified by specific keywords ("all", "new", "save", etc.), and then end with the route that is just an id.Regarding the ordering, there is an example in the "ACTION SKIPPING"
section of Dancer::Introduction, even though the example is a bit wrong
because it does not include the due "return" before pass (see
documentation about "pass" for this). This is how it should be:
get'/say/:word' => sub {
return pass if (params->{word} =~ /^\d+$/);
"I say a word:".params->{word};
};
get'/say/:number' => sub {
"I say a number:".params->{number};
};
If I get the ordering wrong, I can end up with unexpected results.
I have another question regarding putting only similar routes in a single package, but I will save that for another email.
Dancer-users@perldancer.org <mailto:Dancer-users@perldancer.org><mailto:punk.kish@gmail.com>> wrote:
I have widgets called "foo," and I am building web app that will
also serve as a RESTful app for data access via the command line.
All "foo" related routes are packaged together, and are loaded via
`load_app "app::foo", prefix => "/foo"`
so that `get '/:foo_id'` really become `http://server/foo/:foo_id`
<http://server/foo/:foo_id>.
My routes are
1. get '/'
===========
Returns a welcome page via a full html request. A full html request
is where a full web page is loaded, as opposed to an ajax request
where only a part of the web page is refreshed.
2. get '/all'
==============
Returns minimal info for all valid "foo" from the data store via a
full html request. However, I would also like to return them as a
json string via the command line. Now, when requested via the web
browser, this method should really return only some minimal info for
each "foo." Clicking on any specific "foo" should fire #3 below to
get its details -- a typical drill-down application. However, when
requested via the commandline, there should be an option to return
*all* the details, with some checks, so that gigabytes of data are
not returned.
3. get '/:foo_id'
==================
Returns all the details for a specific "foo" as a json string via an
ajax request.
4. get '/new'
==============
Returns a page to begin constructing a new "foo" in the browser via
a full html request. There is no equivalent command line method for
this.
5. post '/save'
=======================
Saves a new "foo" created in #4 or above, or via a command line
method. In other words, a user should be able to supply in a json
string via the command line everything that a user would create
interactively in #4 above.
6. get '/delete/:foo_id'
=========================
This method removed a specific foo. Now, two things I don't
understand about this -- one, of course, in a RESTful app, this
would be a DELETE method. This is a bit confusing to me -- is the
HTTP get (I am using a lowercase 'get') not the same as a REST GET
(using an uppercase get)? In other words, can I use a `get` to
perform a `DELETE`? Two, how do I send authentication? I don't want
Sukrieh deleting Sawyer's widget.
In fact, this authentication theme runs through all the routes -- do
I just pass a session token for authentication with every route?
Finally, should #3 be the last route? Else, how do I differentiate
between `get '/delete/5'` and `get '/5'` and `get '/all'`?
Thanks in advance for a quick lesson, whosoever cares to give one.
--
Puneet Kishor
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--
Puneet Kishor http://punkish.org
Carbon Model http://carbonmodel.org
Charter Member, Open Source Geospatial Foundation http://www.osgeo.org
Science Fellow http://creativecommons.org/about/people/fellows#puneetkishor
Nelson Institute, UW-Madison http://www.nelson.wisc.edu
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