Play Framework - how to bind form to a session field - scala

Is there a way I can get some parameters from headers, say cookie (in my case logged in userId), and then apply it to a form so I know who is submitting the ticket?
SupportForm
supportForm:Form[SupportTicket] = Form(mapping(
"question" -> text,
"Priority" -> text
)(SupportTicket.Apply)(SupportTicket.Unapply)
What are the good practises here?
Is request present as an implicit when the call to Apply is made so that I can use it (and is this even a good practise?)
EDIT: One of the issues, ofcourse is someone spoofing if I were to create a hidden field with this value. I could encrypt, but the issue again is to somehow verify and return the form, not sure how this can be done....

Related

Play - Custom validations with custom error message

I am using the Play framework in Scala to develop a small blog website. I currently have a form (successfully) set up for an easy registration of users. This login page just accepts a username (ie. no password yet), verifies that is of the appropriate length and doesn't exist yet, and adds this user to the database (currently still in memory). Length can be verified using just the basic form functionality, however, the uniqueness of this username required me to use custom validations.
Now, this all works, except for the custom error message. When a normal form requirement is not fulfilled, an error message is returned and displayed in the view (eg. "The minimum length is: 5"). I want to display a similar message when the name is not unique. In the first link I provided there is an example of custom validations which seems to have an argument that represents such custom error message for validations you write of your own. However, this does not display in the view, while the others do.
Current validation code:
private val myForm: Form[Account] =
Form(mapping("name" -> text(3, 24))(Account.apply)(Account.unapply).verifying(
"Account is not in the DB.",
fields =>
fields match {
case data: Account => accountExists(data.name).isDefined
}
)
)
Anyone has any ideas?

REST - Updating partial data

I am currently programming a REST service and a website that mostly uses this REST service.
Model:
public class User {
private String realname;
private String username;
private String emailAddress;
private String password;
private Role role;
..
}
View:
One form to update
realname
email address
username
Another form to update the role
And a third form to change the password
.
Focussing on the first view, which pattern would be a good practice?
PUT /user/{userId}
imho not because the form contains only partial data (not role, not password). So it cannot send a whole user object.
PATCH /user/{userId}
may be ok. Is a good way to implement it like:
1) read current user entity
2)
if(source.getRealname() != null) // Check if field was set (partial update)
dest.setRealname(source.getRealname());
.. for all available fields
3) save dest
POST /user/{userId}/generalInformation
as summary for realname, email, username
.
Thank you!
One problem with this approach is that user cannot nullify optional fields since code is not applying the value if (input is empty and value) is null.
This might be ok for password or other required entity field but for example if you have an optional Note field then the user cannot "clean" the field.
Also, if you are using a plain FORM you cannot use PATCH method, only GET or POST.
If you are using Ajax you might be interested in JSON Merge Patch (easier) and/or JavaScript Object Notation (JSON) Patch (most complete); for an overview of the problems that one can find in partial updates and in using PATCH see also this page.
A point is that a form can only send empty or filled value, while a JSON object property can have three states: value (update), null (set null) and no-property (ignore).
An implementation I used with success is ZJSONPATCH
Focussing on the first view, which pattern would be a good practice?
My suggestion starts from a simple idea: how would you do this as web pages in HTML?
You probably start from a page that offers a view of the user, with hyperlinks like "Update profile", "Update role", "Change password". Clicking on update profile would load an html form, maybe with a bunch of default values already filled in. The operator would make changes, then submit the form, which would send a message to an endpoint that knows how to decode the message body and update the model.
The first two steps are "safe" -- the operator isn't proposing any changes. In the last step, the operator is proposing a change, so safe methods would not be appropriate.
HTML, as a hypermedia format, is limited to two methods (GET, POST), so we might see the browser do something like
GET /user/:id
GET /forms/updateGeneralInformation?:id
POST /updates/generalInformation/:id
There are lots of different spellings you can use, depending on how to prefer to organize your resources. The browser doesn't care, because it's just following links.
You have that same flexibility in your API. The first trick in the kit should always be "can I solve this with a new resource?".
Ian S Robinson observed: specialization and innovation depend on an open set. If you restrict yourself to a closed vocabulary of HTTP methods, then the open set you need to innovate needs to lie elsewhere: the RESTful approach is to use an open set of resources.
Update of a profile really does sound like an operation that should be idempotent, so you'd like to use PUT if you can. Is there anything wrong with:
GET /user/:id/generalInformation
PUT /user/:id/generalInformation
It's a write, it's idempotent, it's a complete replacement of the generalInformation resource, so the HTTP spec is happy.
Yes, changing the current representation of multiple resources with a single request is valid HTTP. In fact, this is one of the approaches described by RFC 7231
Partial content updates are possible by targeting a separately identified resource with state that overlaps a portion of the larger resource
If you don't like supporting multiple views of a resource and supporting PUT on each, you can apply the same heuristic ("add more resources") by introducing a command queue to handle changes to the underlying model.
GET /user/:id/generalInformation
PUT /changeRequests/:uuid
Up to you whether you want to represent all change requests as entries in the same collection, or having specialized collections of change requests for subsets of operations. Tomato, tomahto.

How to keep the value in a field from the inputPassword helper in the Play framework?

Excuse me if the answer is obvious but whilst I know Java I am very new to Scala, the Play framework and general web app development.
I have taken on a project that has a view where you can set up some database connection details that includes fields such as database name, username, password etc. At present the code uses the Play input helper 'inputText' and so the password field shows the password in plain text. I need to fix this and so have changed it to use the 'inputPassword' helper however whenever I visit this page in my app to edit one of the other fields the password field has not been populated with the password so the user needs to re-enter it in order to save, I do not want to have to do this.
The password populated when it was an inputText helper so I can only assume that there's something in the inputPassword helper that stops the value from populating in the form, maybe it expects the password field to only be used when inputting a new one? Is there a way to override this and have it fill in the on screen form with the password so the user does not have to re-enter in order to change another field on the page?
This is the old version in my view
#inputField(form("password"), '_label -> "Password", '_labelwidth -> "2", 'class -> "form-control", '_type -> "password", '_single -> false)</code>
This is the new version
#inputPassword(form("password"), '_label -> "Password", '_labelwidth -> "2", 'class -> "form-control", '_single -> false, '_type -> "password")
I then have an the templates inputField.scala.html which contains #helper.inputText(field, args:_*) and the inputPassword.scala.html which contains #helper.inputPassword(field, args:_*)
I tried adding 'value -> form("password").value to the parameters in the inputPassword version and whilst this displayed something in stars in the password field the credentials were incorrect so it cannot have been the correct information.
Any help or suggestions are appreciated, even if it is to just understand why inputText populates the field whereas inputPassword does not. The only other way I can think of to do this is possibly to have the password as a separate form on the same page and make it so the password entry is only mandatory when using the page for the initial set up of the database credentials and optional on the edit page.
I don't think it's really necessary to send password values back and forth for security reasons. As an internet user I've never seen form with filled password.
Regarding your case I see two options:
Either separate password change into another form (but this is usually an option if you have more sophisticated password reset process, like two-step verification)
Or apply the following password validation logic on the server: leave the password unchanged if it is empty

Routing based on query parameter in Play framework

My web application will be triggered from an external system. It will call one request path of my app, but uses different query parameters for different kinds of requests.
One of the parameters is the "action" that defines what is to be done. The rest of the params depend on the "action".
So I can get request params like these:
action=sayHello&user=Joe
action=newUser&name=Joe&address=xxx
action=resetPassword
...
I would like to be able to encode it similarly in the routes file for play so it does the query param based routing and as much of the validation of other parameters as possible.
What I have instead is one routing for all of these possibilities with plenty of optional parameters. The action processing it starts with a big pattern match to do dispatch and parameter validation.
Googling and checking SO just popped up plenty of samples where the params are encoded in the request path somehow, so multiple paths are routed to the same action, but I would like the opposite: one path routed to different actions.
One of my colleagues said we could have one "dispatcher" action that would just redirect based on the "action" parameter. It would be a bit more structured then the current solution, but it would not eliminate the long list of optional parameters which should be selectively passed to the next action, so I hope one knows an even better solution :-)
BTW the external system that calls my app is developed by another company and I have no influence on this design, so it's not an option to change the way how my app is triggered.
The single dispatcher action is probably the way to go, and you don't need to specify all of your optional parameters in the route. If action is always there then that's the only one you really need.
GET /someRoute controller.dispatcher(action: String)
Then in your action method you can access request.queryString to get any of the other optional parameters.
Note: I am NOT experienced Scala developer, so maybe presented snippets can be optimized... What's important for you they are valid and working.
So...
You don't need to declare every optional param in the routes file. It is great shortcut for type param's validation and best choice would be convince 'other company' to use API prepared by you... Anyway if you haven't such possibility you can also handle their requests as required.
In general: the dispatcher approach seems to be right in this place, fortunately you don't need to declare all optional params in the routes and pass it between actions/methods as they can be fetched directly from request. In PHP it can be compared to $_GET['action'] and in Java version of Play 2 controller - DynamicForm class - form().bindFromRequest.get("action").
Let's say that you have a route:
GET /dispatcher controllers.Application.dispatcher
In that case your dispatcher action (and additional methods) can look like:
def dispatcher = Action { implicit request =>
request.queryString.get("action").flatMap(_.headOption).getOrElse("invalid") match {
case "sayHello" => sayHelloMethod
case "newUser" => newUserMethod
case _ => BadRequest("Action not allowed!")
}
}
// http://localhost:9000/dispatcher?action=sayHello&name=John
def sayHelloMethod(implicit request: RequestHeader) = {
val name = request.queryString.get("name").flatMap(_.headOption).getOrElse("")
Ok("Hello " + name )
}
// http://localhost:9000/dispatcher?action=newUser&name=John+Doe&address=john#doe.com
def newUserMethod(implicit request: RequestHeader) = {
val name = request.queryString.get("name").flatMap(_.headOption).getOrElse("")
val address = request.queryString.get("address").flatMap(_.headOption).getOrElse("")
Ok("We are creating new user " + name + " with address " + address)
}
Of course you will need to validate incoming types and values 'manually', especially when actions will be operating on the DataBase, anyway biggest part of your problem you have resolved now.

Play 2.0 password field constructor: no value attrib?

Not sure if this is a security feature, an oversight, or me missing the ocean for the waves, but wondering why there is no value attribute for the password field constructor
This is not an issue for user signup and other form creation events, but becomes a headache when, for example, a user renewal form does not have the password field filled in (and thus fails validation, which is ironic given that they just logged in in order to be able to renew in the first place ;-))
My workaround has been to set the value attrib manually by supplying it as an extra argument:
#inputPassword(
_form("password"), '_label-> "Password*", 'class-> "required",
'value-> _form("password").value map{Some(_)} getOrElse Some("")
)
would prefer the value attribute included by default, however, as with other input elements. Yes, I can override it, but wondering what the dealy-O is regardless
To me, you shouldn't be able to retrieve the user password in any way, since the password should be encrypted before storing it somewhere.