How do I parse a POST to my Rails 3.1 server manually? - https

Scenario:
I have a Board model in my Rails server side, and an Android device is trying to post some content to a specific board via a POST. Finally, the server needs to send back a response to the Android device.
How do I parse the POST manually (or do I need to)? I am not sure how to handle this kind of external request. I looked into Metal, Middleware, HttpParty; but none of them seems to fit what I am trying to do. The reason I want to parse it manually is because some of the information I want will not be part of the parameters.
Does anyone know a way to approach this problem?
I am also thinking about using SSL later on, how might this affect the problem?
Thank you in advance!! :)


I was trying to make a cross-domain request from ie9 to my rails app, and I needed to parse the body of a POST manually because ie9's XDR object restricts the contentType that we can send to text/plain, rather than application/x-www-urlencoded (see this post). Originally I had just been using the params hash provided by the controller, but once I restricted the contentType and dataType in my ajax request, that hash no longer contained the right information.
Following the URL in the comment above (link), I learned the how to recover that information. The author mentions that in a rails controller we always have access to a request variable that gives us an instance of the ActionDispatch::Request object. I tried to use request.query_string to get at the request body, but that just returned an empty string. A bit of snooping in the API, though, uncovered the raw_post method. That method returned exactly what I needed!
To "parse it manually" you could iterate over the string returned by request.raw_post and do whatever you want, but I don't recommend it. I used Rack::Utils.parse_nested_query, as suggested in Arthur Gunn's answer to this question, to parse the raw_post into a hash. Once it is in hash form, you can shove whatever else you need in there, and then merge it with the params hash. Doing this meant I didn't have to change much else in my controller!
params.merge!(Rack::Utils.parse_nested_query(request.raw_post))
Hope that helps someone!


Not sure exactly what you mean by "manually", posts are normally handled by the "create" or "update" methods in the controller. Check out the controller for your Board model, and you can add code to the appropriate method. You can access the params with the params hash.
You should be more specific about what you are trying to do. :)

Related

Is it necessary to use the form to transfer data to the server?

I'm new to backend programming. I chose the laravel framework. Already learned the basics. During the study, the question arose: is it necessary to use the form to transfer data to the server ?. For example: the deletion route looks like this to me
Delete.
If I leave it, will it be a mistake? Maybe advise an article or something. Thanks in advance

Short answer is no, it's not necessary, but you should (if you're bound to HTML only).
The HTTP standard has different methods for different purposes. Using an anchor tag will always make a HTTP GET request to the link/server, which is not ideal, GET request should never change the remote (server) state, that's a job other methods (POST, PUT, DELETE, PATCH), you should try to use the method that better describe what you're trying to do: in your case I suppose you're trying to delete a complaint, so a DELETE or POST is what you're looking for.
The only way to use make a non GET request in plain HTML* is to use <form>. Also if you're planning to use a method different from POST you should take a look at Laravel's #method here
Mind that if you can and want to use JavaScript to perform your request you totally can, dropping the requirement to have use form (docs and docs).

Google Api Ruby Client to return the actual HTTP response, not the helper object

Is there an easy way to ask the google api ruby client to just give you back the stock HTTP response, rather than to perform the lovely, but slightly limiting translation into one of their ruby representable objects?
e.g.
response = Gmail.client.get_user_message("me", id)
=> #<Google::Apis::GmailV1::Message
response = Gmail.client.list_user_messages("me")
=> #<Google::Apis::GmailV1::ListMessagesResponse
but
response = Gmail.client.delete_user_message("me", id)
=>nil #successfully deleted
Now that's all fine and dandy, except that sometimes I just want to know what sort of response is going to come back. i.e. an HTTP response with maybe some JSON in the body. And then I'll worry about what I do with it...
I can take the response and use the
response.to_json
to get the body of the json that would have come back (though I still won't have the response code, and I need to KNOW that it's one of those objects first).
The client library is definitely getting that, it's just converting it into these objects before it lets me see it. And if I don't know that it's a google object (and not nil) I can't run that to_json consistently....
Any ideas other than second guess what google is going to send me back?
(I should note that this has come about when trying to move a library from dealing with their 0.8 api to their 0.9 api, so call me a cynic if you must but my faith that google won't make breaking changes to those objects returned is at a low ebb...

As far as I know, it is possible to ask the server to send only the fields you really need and get a partial response instead of the default full response as mentioned in Performance Tips.
However, I suggest that you please check the documentation for the specific API you are using to see if the field you're looking for is currently supported. For the Gmail API, you may go through Working with partial resources.
Here are the two types of partial requests that you can use:
Partial response: A request where you specify which fields to include in the response (use the fields request parameter).
Patch: An update request where you send only the fields you want to change (use the PATCH HTTP verb).
Hope that helps!

I need to convert any string without GET parameters

I need to convert any string without GET parameters:
www.mysite.com/?a=5&s=5 ---> www.mysite.com/
www.mysite.com/books/?bla=blabla&bla=4 ---> www.mysite.com/books/
I need to hide $_GET parameters.
I cant use POST parameters.
How can i do this ?

Then use POST.
POST-Data is not visible in the url and can be used like GET, but has to be pushed from a HTML-Form or something

Variables submitted by the method GET go in the URL, so it's impossible to hide them. However, you can make them prettier using the MVC architectural pattern. It's a more sofisticate solution that really pays off, in terms of organization.
For example, URLs like mysite.com/?a=5&s=5 would become mysite.com/5/5
You used $_GET[], so I assume you're using PHP. Take a look at Laravel or Phalcon.
In case you do not want to show any of the variables, you have to use POST. Data submitted by POST is inserted in the body of the HTTP request. Please, keep in mind that the body will not be encrypted, unless you use HTTPS.

GET vs POST in AJAX?

Why are there GET and POST requests in AJAX as it does not affect page URL anyway? What difference does it make by passing sensitive data over GET in AJAX as the data is not getting reflected to page URL?

You should use the proper HTTP verb according to what you require from your web service.
When dealing with a Collection URI like: http://example.com/resources/
GET: List the members of the collection, complete with their member URIs for further navigation. For example, list all the cars for sale.
PUT: Meaning defined as "replace the entire collection with another collection".
POST: Create a new entry in the collection where the ID is assigned automatically by the collection. The ID created is usually included as part of the data returned by this operation.
DELETE: Meaning defined as "delete the entire collection".
When dealing with a Member URI like: http://example.com/resources/7HOU57Y
GET: Retrieve a representation of the addressed member of the collection expressed in an appropriate MIME type.
PUT: Update the addressed member of the collection or create it with the specified ID.
POST: Treats the addressed member as a collection in its own right and creates a new subordinate of it.
DELETE: Delete the addressed member of the collection.
Source: Wikipedia

Well, as for GET, you still have the url length limitation. Other than that, it is quite conceivable that the server treats POST and GET requests differently; thus the need to be able to specify what request you're doing.

Another difference between GET and POST is the way caching is handled in browsers. POST response is never cached. GET may or may not be cached based on the caching rules specified in your response headers.

Two primary reasons for having them:
GET requests have some pretty restrictive limitations on size; POST are typically capable of containing much more information.
The backend may be expecting GET or POST, depending on how it's designed. We need the flexibility of doing a GET if the backend expects one, or a POST if that's what it's expecting.

It's simply down to respecting the rules of the http protocol.
Get - calls must be idempotent. This means that if you call it multiple times you will get the same result. It is not intended to change the underlying data. You might use this for a search box etc.
Post - calls are NOT idempotent. It is allowed to make a change to the underlying data, so might be used in a create method. If you call it multiple times you will create multiple entries.

You normally send parameters to the AJAX script, it returns data based on these parameters. It works just like a form that has method="get" or method="post". When using the GET method, the parameters are passed in the query string. When using POST method, the parameters are sent in the post body.
Generally, if your parameters have very few characters and do not contain sensitive information then you send them via GET method. Sensitive data (e.g. password) or long text (e.g. an 8000 character long bio of a person) are better sent via POST method.

Thanks..
I mainly use the GET method with Ajax and I haven't got any problems until now except the following:
Internet Explorer (unlike Firefox and Google Chrome) cache GET calling if using the same GET values.
So, using some interval with Ajax GET can show the same results unless you change URL with irrelevant random number usage for each Ajax GET.

Others have covered the main points (context/idempotency, and size), but i'll add another: encryption. If you are using SSL and want to encrypt your input args, you need to use POST.

When we use the GET method in Ajax, only the content of the value of the field is sent, not the format in which the content is. For example, content in the text area is just added in the URL in case of the GET method (without a new line character). That is not the case in the POST method.

GET vs POST in Ajax

What is the difference between GET and POST for Ajax requests?
I don't see any difference between those two, except that when I use GET, the parameters are send in URL, which for me don't really make any difference, since all requests are made on background and user doesn't find any difference.
edit:
What are PUT and DELETE methods used for?

GET is designed for getting data from the server. POST (and lesser-known friends PUT and DELETE) are designed for modifying data on the server.
A GET request should never cause data to be removed from an application. If you have a link you can click on with a GET to remove data, then Google spidering your site could click on all your "Delete" links.
The canonical answer can be found here, which quotes the HTML 2.0 spec:
If the processing of a form is idempotent (i.e. it has no lasting
observable effect on the state of the
world), then the form method should be
GET. Many database searches have no
visible side-effects and make ideal
applications of query forms.
If the service associated with the processing of a form has side effects
(for example, modification of a
database or subscription to a
service), the method should be POST.
In your AJAX call, you need to use whatever method your server supports. You should always design your server so that operations that modify data are called by POST/PUT/DELETE. Other comments have links to REST, which generally maps C/R/U/D to "POST or PUT"(Create)/GET(Read)/PUT(Update)/DELETE(Delete).

If you're sending large amounts of data, or sensitive data over HTTPS, you will want to use POST. If it's just a simple parameter, I would use GET.
GET requests have a limit to the amount of data that can be sent. I forget the exact number, but this can cause issues if you're sending anything substantial.
Basically the difference between GET and POST is that in a GET request, the parameters are passed in the URL where as in a POST, the parameters are included in the message body.

Whether its AJAX or not is irrelevant. Its about the action that you're taking. I'd recommend following the principles of REST. Which have further provisions for updating, deleting, etc...

GET requests are easier to exploit in CSRF (cross site request forgery) attacks. Namely fake POST requests require Javascript to be enabled on the user side, while fake GET requests are still possible just with img, script tags.

Many web servers limit the length of the data that can be passed as part of the URL, so the GET request may break in odd ways that are hard to debug.
Also, most server software logs URLs in the access logs, so if you pass sensitive information (such as passwords) in a GET request, this will in all likelihood be written to disk in plaintext.
From a REST perspective, GET requests should have no side-effects -- they shouldn't modify data. So, if you're just GETting a resource by ID, this makes sense, but if you're committing changes to a resource, you should be using PUT, POST, or UPDATE for the http verb.

Both are used to send some data and receive some response using that data.
GET: Get information store in server. Ie. Search, tweet, Person Information. If you want to send information then get request send request using process.php?name=subroto
So it basically send information through url. Url cannot handle more than 2083 char. So for blog post can you remember it is not possible?
POST: Post do same thing as get. User registration, User login, Big data send, Blog Post.
If you need to send secure information then use post or for big data as it not go through url.
AJAX: $.get() and $.post() contain features that are subsets of $.ajax(). It has much configuration.
$.get () method, which is a kind of shorthand for $.Ajax (). When using $.get (), instead of passing in an object, you pass in arguments. At minimum, you’ll need the first two arguments, which are the URL of the file you want to retrieve (i.e. ‘test.txt’) and a success callback.
Summary:
$.get( url [, data ] [, success ] [, dataType ] )
$.post( url [, data ] [, success ] [, dataType ] ) // for sending secure or Large information
$.ajax( url [, settings ] ) // More Configaration

First, general information. Use GET if you only read data, use POST if you change something on database, txt files etc.
But the problem is, some browsers cache GET results. I had problems with AJAX requests in IE7, but at last I found out that browser caches GET results. I rethought the flow and changes my request to POST.
So, don't use GET if you don't want caching.
(Of course you can disable caching in GET operations. But I didn't prefer it)

About me, i prefer POST. I reserve get to the events i know the sent value is limited to data i have the "control", for example, to retreive an item with an id. Example, "getitem?id=123", "deleteImtem?id=123", ... For the other cases, when i have a form fillable by a user, i prefer POST.
Like Ryan Smith have said, it's better to use POST to send a large amount of data, and less wories in cases of the use in others language/special chars (generally all majors javascript framework should'nt have any problems to deal with that but i think is less wories to use POST).
For the REST perspective, in my opinion, you can use this with a new project (to keep a consistency with the entire project).
Finally, maybee some programs used in a network (URL loguers (ie.: to see if the employees lost their time on non-autorised sites, ...) proxys, ... ) or any other kind of tool can intercept the query. Somes will show in the reports the params you have sent with GET, considering it like a different web page. But in this situation, is could be not your problem it's changes from a project to an other! ;)

The difference is the same between GET and POST whether you're using Ajax, HTML forms, or curl. Here are the relevant definitions:
GET
POST

If you are passing on any arguments with characters that can get messed up in the URL (such as spaces), you use POST. Otherwise you can use GET.
Generally, if you're just passing on a few tiny arguments you would use GET. But for passing on user submitted information such as blog entries, text, etc, its a good practice to use POST.
There are also certain frameworks that rely completely on segment based urls (such as site.com/products/133 rather than site.com/products.php?id=333 and these frameworks unset the GET variables for security. In such cases you would use POST allt the time.

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