Ok, this is my Nth question regarding this topic, and I'm getting really frustrated with Grails. Please have a quick look on one of my earlier questions for more details.
Among other things, my problem is that sending JSON formatted data to the controller when testing doesn't seem to work. The controller doesn't get null object, but the argument passed is practically empty--the JSON properties don't get set.
Aside from the controller code from the link above, I also tried,
def save() {
def model = new MyModel(request.JSON)
model.save()
}
but it still fails to set properties.
From my Web searches, I read that in older versions, parseRequest must be set to true in UrlMapping.groovy so that request data formatted in XML, JSON, etc. would automatically be parsed and passed as controller method argument. I'm working on Grails 2.3.9, and I'm not sure if it's still necessary to do that.
The time I thought I'd save if I use Grails on this project is being spent on looking for an answer to this seemingly simple task of testing a RESTful Web service.
No since 2.3.0 the parseRequest option doesn't do anything. The request is parsed lazily only when request.XML or request.JSON is accessed or when binding to a command object.
Related
I've been using arrow-kt and spring together a lot lately. I've actually constructed a bridge between the two with several key features, one of which is a spring controller that returns an Either will automatically unwrap it and either handle the exception (Left) or return the result (Right). My long term goal is to publish this as a library.
My latest obstacle is Swagger, or more accurately springdoc openapi. Obviously it is seeing the Either, but i want it to show only the Right value as the success response type. While I know there are annotations where I can set the response model on each controller method individually, I'm trying to avoid this.
My real goal is to setup some global converter so that wherever Swagger sees an Either it will automatically unpack this. I'm just not super familiar with the customization API in Spring doc, and everything I Google just points me to the ApiResponse annotation solution.
How can I define default handling for this type of response?
I have read a few posts here and on GitHub regarding .NET Core 3.1's change in tightening of the allowance of serializing data. My actual exception is:
System.Text.Json.JsonException: 'A possible object cycle was detected which is not supported. This can either be due to a cycle or if the object depth is larger than the maximum allowed depth of 0.'
When I search the web, there are very few results, but from what I gather, it's telling me that it doesn't like the related data that is being serialized. Well, in the past, this hasn't been a problem. After reading this post, it says to install the Newtonsoft Json serializer package. I did that, and added the verbiage in Startup, but got the same result. So, I read another post here where the member who answered the question returned a JsonResult in the method. I tried this as a test and it worked just fine. Problem is, I need to return the data (serialized) to a view.
My question is, why can the standard System.Text.Json.JsonSerializer not serialize my data, yet a JsonResult can? Either way, I just need to serialize my data and cannot get past this error and any help would be greatly appreciated. If I have to return the data via an API and continue to use the JsonResult, I'm fine with that, but am concerned as to why it works.
As #poke suggested, using Json.Serialize works. I was using System.Text.Json.JsonSerializer.Serialize(Model) and for some strange reason, this throws the same exception even though the Ignore option is set in Startup. More research is required, but at least this gives me something to look into.
It took me a while to understand this, being that it was a little obvious. I will answer myself, so other can benefit of the answer and ofcourse to see if there's a better way to do this. The problem was based on Axios/Yii2 but I guess this will apply equally to other frontend libraries/frameworks sending data to Yii2.
I needed to post data from a small form made on Vuejs, sending the request Axios to a Action/Controller on Yii2, so data is sent on a simple POST request and the post is getting to the controller, but I was not able to receive the data on the action, $_POST | $post arrives empty (checked using xdebug).
As much as I remember, this had something to do with security. But I already tried by disabling public $enableCsrfValidation, so that was not the problem.
public $enableCsrfValidation = false;
But no matter what, data was not being added to the request/post data inside Yii2.
The following Image, explains the problem you will find there:
The Axisos method that sends the post with test data.
The Yii2 Action stpoed at the place, I should be able to see data.
The capture of the xdebug variables and data for the request.
The capture of Chrome where you can check the payload is sent.
The answer is as I said "kind of obvious", but I could not see that, and I am sure some other devs will probably fall on this.
After searching like crazy and asking everyone, I tried sending the request by using Postman app, yup the best thing I know to test apis.
Dont forgue to add the xdebug cookie to be able to debug your PHP Endpoint.
There I found the first clue «the obvious part», I was not sending data as a form-data, Axios and other libraries, send the data as a raw (application/json) payload.
This means that Yii2 will no be able to find the data inside the post request, yes its there but Yii2 magic will not work, neither you will find this data inside $GLOBALS or in $_POST.
So reading the Yii2 documentation I found that inside request I can use a function that will help me recovering the Raw data, so to do this use the following line:
$raw_data = Yii::$app->request->getRawBody();
Now, that data gets to you as a simple, raw json string, so use the power of PHP to parse it to an object.
$object= json_decode($raw_data );
And finally use the data inside by calling the properties you look for, sent on the pay load:
Json Payload:
{
"msg":"This is my payload",
"id":"11"
}
To use it:
echo $object->{'msg'}; // prints: This is my payload
So that's the way to handle that, now I would like some other points of view to see if there's a better way or cleaner way to do this. Hope it helps.
I have a Restlet application already working that accepts JSON and returns JSON entity as response.
I'm trying to understand how I can compress the JSON entity that is returned in the response.
I did not find any clear example on how to achieve it.
I think I have to put somewhere on the router chain the Encoder/EncoderService classes, but I really don't understand where and how to use them.
Could anybody help me?
After some testing, I got the answer.
Creating a new filter like this
Filter encoder = new Encoder(getContext(), false, true, new EncoderService(true));
inside the createInboundRoot() method of my own Application class did the trick, the client requests were already containing the gzip header needed.
I'm developing a RESTful interface which is used to provide JSON data for a JavaScript application.
On the server side I use Grails 1.3.7 and use GORM Domain Objects for persistence. I implemented a custom JSON Marshaller to support marshalling the nested domain objects
Here are sample domain objects:
class SampleDomain {
static mapping = { nest2 cascade: 'all' }
String someString
SampleDomainNested nest2
}
and
class SampleDomainNested {
String someField
}
The SampleDomain resource is published under the URL /rs/sample/ so /rs/sample/1 points to the SampleDomain object with ID 1
When I render the resource using my custom json marshaller (GET on /rs/sample/1), I get the following data:
{
"someString" : "somevalue1",
"nest2" : {
"someField" : "someothervalue"
}
}
which is exactly what I want.
Now comes the problem: I try to send the same data to the resource /rs/sample/1 via PUT.
To bind the json data to the Domain Object, the controller handling the request calls def domain = SampleDomain.get(id) and domain.properties = data where data is the unmarshalled object.
The binding for the "someString" field is working just fine, but the nested object is not populated using the nested data so I get an error that the property "nest2" is null, which is not allowed.
I already tried implementing a custom PropertyEditorSupport as well as a StructuredPropertyEditor and register the editor for the class.
Strangely, the editor only gets called when I supply non-nested values. So when I send the following to the server via PUT (which doesn't make any sense ;) )
{
"someString" : "somevalue1",
"nest2" : "test"
}
at least the property editor gets called.
I looked at the code of the GrailsDataBinder. I found out that setting properties of an association seems to work by specifying the path of the association instead of providing a map, so the following works as well:
{
"someString" : "somevalue1",
"nest2.somefield" : "someothervalue"
}
but this doesn't help me since I don't want to implement a custom JavaScript to JSON object serializer.
Is it possible to use Grails data binding using nested maps? Or do I really heave to implement that by hand for each domain class?
Thanks a lot,
Martin
Since this question got upvoted several times I would like to share what I did in the end:
Since I had some more requirements to be implemented like security etc. I implemented a service layer which hides the domain objects from the controllers. I introduced a "dynamic DTO layer" which translates Domain Objects to Groovy Maps which can be serialized easily using the standard serializers and which implements the updates manually. All the semi-automatic/meta-programming/command pattern/... based solutions I tried to implement failed at some point, mostly resulting in strange GORM errors or a lot of configuration code (and a lot of frustration). The update and serialization methods for the DTOs are fairly straightforward and could be implemented very quickly. It does not introduce a lot of duplicate code as well since you have to specify how your domain objects are serialized anyway if you don't want to publish your internal domain object structure. Maybe it's not the most elegant solution but it was the only solution which really worked for me. It also allows me to implement batch updates since the update logic is not connected to the http requests any more.
However I must say that I don't think that grails is the appropriate tech stack best suited for this kind of application, since it makes your application very heavy-weight and inflexbile. My experience is that once you start doing things which are not supported by the framework by default, it starts getting messy. Furthermore, I don't like the fact that the "repository" layer in grails essentially only exists as a part of the domain objects which introduced a lot of problems and resulted in several "proxy services" emulating a repository layer. If you start building an application using a json rest interface, I would suggest to either go for a very light-weight technology like node.js or, if you want to/have to stick to a java based stack, use standard spring framework + spring mvc + spring data with a nice and clean dto layer (this is what I've migrated to and it works like a charm). You don't have to write a lot of boilerplate code and you are completely in control of what's actually happening. Furthermore you get strong typing which increases developer productivity as well as maintainability and which legitimates the additional LOCs. And of course strong typing means strong tooling!
I started writing a blog entry describing the architecture I came up with (with a sample project of course), however I don't have a lot of time right now to finish it. When it's done I'm going to link to it here for reference.
Hope this can serve as inspiration for people experiencing similar problems.
Cheers!
It requires you to provide teh class name:
{ class:"SampleDomain", someString: "abc",
nest2: { class: "SampleDomainNested", someField:"def" }
}
I know, it requires different input that the output it produces.
As I mentioned in the comment earlier, you might be better off using the gson library.
Not sure why you wrote your own json marshaller, with xstream around.
See http://x-stream.github.io/json-tutorial.html
We have been very happy with xstream for our back end (grails based) services and this way you can render marshall in xml or json, or override the default marshalling for a specific object if you like.
Jettison seems to produce a more compact less human readable JSON and you can run into some library collision stuff, but the default internal json stream renderer is decent.
If you are going to publish the service to the public, you will want to take the time to return appropriate HTTP protocol responses for errors etc... ($.02)