OptionalParameters returned with curly braces in the link response

[navkmurthy]

public TemplateVariables concat(Collection variables) {
...
}
Returns "{?view}" and as a result the link created contains {?view} appended in the end (with the extra curly braces).
I suspect that the value returned should not have curly braces.

Here "view" is an optional parameter in the restful controller
...
@RequestParam(value = "view", required = false) String viewString
..

Below mentioned is the snippet of the response with contains the optional parameters
.....
"_links": {
"self": {
"href": "http://localhost:8080/v1/school/00000000-0000-0000-0000-000000000000{?view}",
"templated": true
},
"members": {
"href": "http://localhost:8080/v1/school/00000000-0000-0000-0000-000000000000/members{?view}",
"templated": true
}
}
....

[odrotbohm]

Depending on what your actual point is, that's correct. The template variable created for the link to that controller method expresses exactly, what the method expresses, that it takes an optional parameter named view. The fact that the href is a URI template and not a URI is also expressed by the template flag set to true.

If you want to create a canonical link, call expand() without any parameters and you'll get a link without any placeholders.

[navkmurthy]

I have used linkTo and methodOn...Please let me know is the API's that I have used need to be modified

......

import static org.springframework.hateoas.core.DummyInvocationUtils.methodOn;
import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;

@RequestMapping
public ResponseEntity findAll(
@QuerydslPredicate(root = School.class) Predicate predicate,
@RequestParam(value = "view", required = false) String viewString,
Pageable pageable
) {
// Query resources
ResourcePage resources = getService().findAll(predicate, pageable);
// Add hateoas links
resources.forEach(resource -> {
resource.add(linkTo(methodOn(SchoolController.class).findOne(resource.getUuid(), viewString)).withSelfRel());
resource.add(linkTo(methodOn(SchoolMemberController.class).findAll(resource.getUuid(), null, null, null)).withRel("members"));
});
UriComponentsBuilder rootUri = linkTo(methodOn(SchoolController.class).findAll(predicate, viewString, pageable)).toUriComponentsBuilder();
resources.buildPageLinks(rootUri);
// Map view to response
MappedResource response = new MappedResource(resources, viewString, SchoolResource.View.class, SchoolResource.View.Default.class);
return ResponseEntity.ok(response);
}
....

[navkmurthy]

The same code with the spring versions mentioned below returns without optional parameter

springBootVersion = "1.4.3.RELEASE"
springCloudVersion = "Camden.SR3"
Spring HATEOAS to 0.20.0.RELEASE
apply plugin: "spring-boot"
.....
"_links": {
"self": {
"href": "http://localhost:8080/v1/school/00000000-0000-0000-0000-000000000000",
"templated": true
},
"members": {
"href": "http://localhost:8080/v1/school/00000000-0000-0000-0000-000000000000/members",
"templated": true
}
}
....

and the version that is currently used is

springBootVersion = "1.5.1.RELEASE"
springCloudVersion = "Camden.SR5"
Spring HATEOAS to 0.23.0.RELEASE
apply plugin: "org.springframework.boot"

Hope this helps.

[Bert-R]

I'm running into the same thing when upgrading from Spring Boot 1.4.7 to 1.5.7

[aayoustic]

Hi @odrotbohm ,
I'm trying to use the expand method, but doesn't work properly it does remove the extra optional parameters but malformed the other query param values.

The url goes like-

https://faloola.com//v1/hello-world?firstParam=abcd&secondParam=Hello%20world{&thirdParam}

After using expand-
https://faloola.com//v1/hello-world?firstParam=abcd&secondParam=Hello%252520world

Do focus on the value of the secondParam

I think it encoded it twice, by using build method and then new Link again.
Can you please look into this?

[odrotbohm]

@aayoustic – Which version are you using? We just recently fixed a couple of double encoding issues.

[aayoustic]

Hey @odrotbohm,
We're using 0.25.0.RELEASE.

[gregturn]

0.25.0.RELEASE was released in the middle of 2018. 0.25.2.RELEASE is the latest stable version of 0.25.x.

That being said, the odds of the double encoding solution @odrotbohm is referencing getting backported are close to zero.

My recommendation is to try migrating to the latest stable 1.1 version version (using our migration script) and seeing if that fixes your problem.

[aayoustic]

@gregturn -
Did you mean 1.0.1.RELEASE?

[gregturn]

Actually, it appears Ollie backported that to the 1.0 branch through #1131, so indeed you can pick the latest version 1.0.3.RELEASE) and give it a spin.

[aayoustic]

Sure thanks!