Default value for collectionFormat field is csv. Should be multi.

[pedrombl]

Currently the default value in the field collectionFormat is csv. However the default way of passing a list of parameters is multi (foo=bar&foo=baz). Talking with ron, who_ and jeremyw in #swagger/freenode this was identified as a bug.

Here is the part of the code that does that ->

swagger-core/modules/swagger-jaxrs/src/main/java/io/swagger/jaxrs/ParameterProcessor.java

Line 97 in 9c67549

p.collectionFormat("csv");

[webron]

For the sake of documentation, the format is csv because of the intent in 1.3.X and we tried to keep it backwards compatible. However, since it really doesn't make sense and breaks the API documentation then it definitely needs to be multi. I believe this makes allowMultiple obsolete, but for now it should probably also give a multi value.

[webron]

Fixed in develop_2.0.

[Armanda888]

Can I set collectionFormat to be csv for query parameter? as my rest api is like foo=bar, baz

[fehguy]

yes you can

[Armanda888]

@fehguy how do I set it? in the annotation ApiParam?

[Armanda888]

by checking https://github.com/kongchen/swagger-maven-plugin/blob/master/src/main/java/com/github/kongchen/swagger/docgen/reader/AbstractReader.java, Line 417, it sets collectionFormat to multi for query param.
Here is my query parameter:
ApiParam(name = "include", allowableValues = "a, b", allowMultiple = true, required = false)
@QueryParam("include") String include,
in the swagger.json, it's like this:
{
"name" : "include",
"in" : "query",
"required" : false,
"type" : "array",
"items" : {
"type" : "string",
"default" : "csv",
"enum" : [ "a", "b" ]
},
"collectionFormat" : "multi"
}

[gkozyryatskyy]

@Armanda888 do you solve your question? have the same problem after update.
There is a support of collectionFormat now available in annotations #1180, but seems swagger plugin do not use it.

[gkozyryatskyy]

@fehguy can you please show how we can set collectionFormat to csv through annotations + swagger plugin?

[fehguy]

@gkozyryatskyy what swagger plugin are you referring to? If this is springfox, then it's a separate project that may not support the latest annotations.

[gkozyryatskyy]

@fehguy this one https://github.com/kongchen/swagger-maven-plugin
seems like the problem is somewhere here https://github.com/kongchen/swagger-maven-plugin/blob/master/src/main/java/com/github/kongchen/swagger/docgen/reader/AbstractReader.java#L441

[fehguy]

OK looks like we need to open a ticket in that project.

[gkozyryatskyy]

@fehguy
done kongchen/swagger-maven-plugin#425

[apiwoni]

@gkozyryatskyy @fehguy This issue has nothing to do with swagger-maven-plugin but more with ParameterProcessor in swagger-core 1.5.x. Currently setting collectionFormat to csv via annotation is ignored when producing swagger json spec because io.swagger.models.parameters.AbstractSerializableParameter#setType resets collectionFormat to null after it has been set to "csv" anytime type is not array.