I want to route requests in a way similar to how Python web.py or Python bottle does it.
With these frameworks you can simply add tags into the URL which can be used to pass parameters, eg:
#route('/api/part1/<tag1name>/part2/<tag2name>')
def handlerfunction(self, tag1name, tag2name):
CherryPy does have the popargs decorator, eg
#cherrypy.popargs('name')
However when there is more than one value encoded in the URI it becomes quite inconvenient to get them assigned to the parameters the right way.
In addition I want to be able to route based on the HTTP request method, as per the CherryPy MethodDispatcher.
The answer is to use a URL Route-mapping module such as "Routes". "Routes" is developed firstly for Pylons but does have support for CherryPy.
From the Documentation:
Routes is a Python re-implementation of the Rails routes system for mapping URLs to application actions, and conversely to generate URLs. Routes makes it easy to create pretty and concise URLs that are RESTful with little effort.
Routes allows conditional matching based on domain, cookies, HTTP method, or a custom function. Sub-domain support is built in. Routes comes with an extensive unit test suite.
After working through the documentation and getting it to work with CherryPy I will update this answer with some CherryPy specific implementation examples.
Related
I've written a REST server in Delphi XE (using the wizard) and I want to change the URLs a bit so that instead of having
http://192.168.1.84:8080/datasnap/rest/TServerMethods1/GetListings
I get something that looks more like http://192.168.1.84:8080/GetListings
Is there a nice easy of doing this?
The naming convention is (Delphi XE3):
http://my.site.com/datasnap/rest/URIClassName/URIMethodName[/inputParameter]
You can easily change the "datasnap" and "rest" part of the URL in the TDSHTTPWebDispatcher component properties. You can change the Class Name and Method Name of the URL by simply changing the name of your class and method. However, you still have to have 4 components to the URL, so for example it could be:
http://my.site.com/api/v1/People/Listing
See here:
http://docwiki.embarcadero.com/RADStudio/XE3/en/REST#Customizing_the_URL_for_REST_requests
You could put IIS or Apache in between to accomplish this, and indeed rewrite the URL to point to your service the way you like.
That provides some more advantages anyway (security and scalability mostly). For example, you can create a fail-safe setup with double servers, or you can create multiple machines with your service, and have your web server do the load balancing for example.
You'll get extra logging capabilities, and if you easily want to serve other web content it's easy to have a full fledged web server anyway.
URL rewriting is usually done in the web server configuration, in Apache using entries in the .htaccess file
When writing a RESTful API that needs to access different environments such as a lab/test database and a production database, what's the best practices around setting up the API?
Should there be a #PathParam?:
/employee/{emp_id}/{environment}
/{environment}/employee/{emp_id}/
Should there be a #QueryParam?:
/employee/{emp_id}/?environment="test"
/employee/{emp_id}/?environment="prod"
Should there be a field in the payload?:
{"emp_id":"123","environment":"test"}
{"emp_id":"123","environment":"production"}
In fact I see two ways to handle this. The reason to use one or the other corresponds to what is the most convenient to implement in your RESTful application.
Using a path parameter
With this approach, it should be a path parameter at the very beginning of the resource path. So URL would be like this: /{environment}/employee/{emp_id}. Such approach is convenient if you have several applications deployed under different root paths. For example:
/test: application packaged with the configuration for the test environment
/prod: application packaged with the configuration for the production
In this case, applications for each environment are isolated.
Using a custom header
You could also a custom header to specify on which environment to route. Github uses something like that to select the version of the API to use. See this link: https://developer.github.com/v3/#current-version. It's not exactly the same thing but you could have something like that:
GET /employee/{emp_id}
x-env: test
A reverse proxy could handle this header and route the request to the right environment.
I'm not convinced by the approach within the payload since an field environment isn't actually a part of the representation for element resource employee. Regarding the query parameter approach, it's similar since such parameters apply to the request on the resource.
Hope it helps you,
Can the REST support in CF10 be used to replace the use of URL Rewrite / ModRewrite for SEO-friendly URL? Write a thin layer that defines the GET and POST method, and <cfinclude> in the correct page?
Or would it tax the server too much and better leave it to the web server to deal with?
Once in CFML, it'd be much easier to be version controlled and maintained.
Thanks
If I understand what you are saying (and perhaps I do not) you would create a handler that would intercept a request, parse out the variables, then request the appropriate page via REST? If that's what you have in mind then I'm not sure I follow what you would gain by this. REST (in general) is more of a generic HTTP API for getting at methods - not so much a page / content paradigm (thought I suppose it could be).
If what you are looking for is to use CF as an rewrite SEO URL handler you can do this now. To use an IIS example, you can create a "custom 404" handler - a CFM page - that gets all the requests that are not tied to a specific document. The handler teases out the variables by parsing through the URL, then "includes" the correct cfm Code or page. That sounds a bit like what you want - but it's not really REST.
Perhaps you are thinking of doing some sort of CFHTTP call where you grab the content you need by constructing the query string from the URL. So if someone loads a url like:
blah.com/productid/550
You could write code like so -
<cfhttp
url="http://blah.com/index.cfm?#listfirst(cgi.script_name,'/')#=#listlast(cgi.script_name,'/')#"/>
<cfoutput>#cfhttp.filecontent#</cfoutput>
While this would do the trick you would be better off using cfinclude rather than this approach. An approach like the one above would actually generate an additional thread per request - one thread for the browser's request and another for the cfhttp request.
Finally I would suggest politely that URL Rewrite (in apache or IIS) is more efficient and more "conventional" and therefore probably a better choice in general.
#Henry
REST is not a replacement for the URL rewriting.
First of all the REST URLs have a format.
http://localhost:8500/rest/App_Name/Rest_Path
"rest" part is mandatory. If you want to change "rest" you can change it in the web.xml (Change the URL Mapping).
App_Name is not mandatory. A server can have a default rest application. For default applications you do not need to specify the AppName. For accessing other (non-default) rest applications, you should specify, the AppName. You can make an application default in the Rest Service registration page in the admin.
Rest_Path identifies the CFC and the function in the CFC that needs to be invoked on the HTTP call.
If these URL format is acceptable, then the URL of these formats can be mapped to a specific function in a CFC. When ever an HTTP call is made to the URL, the corresponding CFFunction will be invoked. By using REST, you are accessing a function in the CFC. It is not possible to access a CFC or a CFM directly in this way. But in the function you can implement whatever you want(Like invoking a CFC, Invoking another CFM etc.).
Does this reply answer your question?
Thanks,
Paul
Even if one could do this, I'd say it's co-opting the wrong tool to do the wrong job. URL rewriting is the web server's job, not the CF server's, and the web server will be a hell of a lot better at it than CF will be. CF's REST interface is for building APIs, not for doing URL rewriting.
If one was to want to handle URL rewriting with CF, then using the 404 handler or onMissingTemplate() handler would be a better fit here, would it not? At least you're using a tool intended for the job (if not the best one).
As for version control... an .htaccess file is just a text file, like a CFML file is. I've not looked too closely at IIS's rewrite module, but can it not use a text file to configure / maintain its rewrites? Obviously Apache can, and we use Helicon's ISAPI Rewrite module which uses an mod_rewrite-compatible .htaccess file.
It seems to me like you're trying to make the developer's job easier by using an approach that would penalise the production performance. "Making the developer's life easier" should never be grounds for compromising the production environment (IMO, obviously).
I am currently re-writing an old web-application and I want it to be RESTful. Now, one important philosophy behind a RESTful app, is that each request to the end-point has to be stateless.
With the application I am aiming for a common codebase for the API as for normal browsing. In other words, I want to avoid special URLs like http://api.domain.tld or http://domain.tld/api. I intend to interpret the HTTP Accept header for this.
One challenge I came up with, are request parameters, that a user browsing the page usually only chooses once. A good example for this is the language. Again, I can use the Accept-Language header to pick an initial language. But what if the user wishes to change this? It would be unusable if the user needed to switch the language after each request.
In my opinion, this is really a request parameter, and should be passed on as such. For example: http://domain.tld/resource?lang=en. So once the user switched the language, I would need to append this parameter to each URL on the page.
In a way, this makes the browsing-session stateful. Are there any "best practices" for this? How would you approach this. One idea I have, is to store these "global" parameters in the session, but add them to each URL nevertheless. If only to make the API easily discoverable.
On a sidenote: I am currently building the web-page using Flask which provides a method url_for to build URLs. I am considering overriding this, so each generated URL will have the parameter. But this is not a Flask specific problem. This is something most RESTful services should consider, so I will tag it neither with python, nor flask!
State Transfer
REST doesn't require each request to be stateless. The requirement is that the server does not have to manage state on behalf of the client. In effect, each request has to carry sufficient state to allow the server to process it.
Your approach, providing the user language is perfectly sensible. Others might prefer to retrieve it from a shared database but this can have some scalability concerns.
I want to ask some questions about the REST call. I am the green for the REST call and I would like to like what is REST call and how to use the URL to send a REST call to the server. Can anyone give me some basic tutorial or link for my to reference?
Besides, if I want to send a REST call to the server, what should I do? Do I need to set something in the URL? or set something in the server? Thank you.
REST is just a software architecture style for exposing resources.
Use HTTP methods explicitly.
Be stateless.
Expose directory structure-like URIs.
Transfer XML, JavaScript Object Notation (JSON), or both.
A typical REST call to return information about customer 34456 could look like:
http://example.com/customer/34456
Have a look at the IBM tutorial for REST web services
REST is somewhat of a revival of old-school HTTP, where the actual HTTP verbs (commands) have semantic meaning. Til recently, apps that wanted to update stuff on the server would supply a form containing an 'action' variable and a bunch of data. The HTTP command would almost always be GET or POST, and would be almost irrelevant. (Though there's almost always been a proscription against using GET for operations that have side effects, in reality a lot of apps don't care about the command used.)
With REST, you might instead PUT /profiles/cHao and send an XML or JSON representation of the profile info. (Or rather, I would -- you would have to update your own profile. :) That'd involve logging in, usually through HTTP's built-in authentication mechanisms.) In the latter case, what you want to do is specified by the URL, and the request body is just the guts of the resource involved.
http://en.wikipedia.org/wiki/Representational_State_Transfer has some details.