New PHP Slim4 Server Generator

[ybelenko]

PR checklist

• Read the contribution guidelines.
• Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh, ./bin/openapi3/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\. If contributing template-only or documentation-only changes which will change sample output, be sure to build the project first.
• Filed the PR against the correct branch: master, 4.1.x, 5.0.x. Default: master.
• Copied the technical committee to review the pull request if your PR is targeting a particular programming language.

Description of the PR

There are breaking changes in Slim 4.0.0 version. In issue #2851 we agreed to add new generator.

I had to update my own Slim Token Authentication fork because original repo author didn't accept my PRs and seems missing.

Upgrade Guide - Slim Framework

Already contains changes from #3621
Closes #2851

cc @jebentier, @dkarlovi, @mandrean, @jfastnacht, @ackintosh, @renepardon

Questions to maintainers

# START SCRIPT: bin/php-slim4-server-petstore.sh
[main] INFO  o.o.codegen.DefaultGenerator - OpenAPI Generator: php-slim4 (server)
[main] INFO  o.o.codegen.DefaultGenerator - Generator 'php-slim4' is considered stable.

1. Generator 'php-slim4' is considered stable seems interesting, where can I change it? This option/flag is not documented as far as I know.
2. What happened with security samples? I remember that I had to run bin/security/php-slim-server-petstore.sh before.
3. Why Openapi 3.0 samples mapped to the same folder where 2.0 samples already exists. I mean ./bin/openapi3/php-slim-server-petstore.sh and ./bin/php-slim-server-petstore.sh scripts targets the same ./samples/server/petstore/php-slim directory.

[ybelenko]

I've just finished testing of all endpoints in petstore-with-fake-endpoints-models-for-testing.yaml file. There are few non-critical issues that I discovered.

1. Slim framework doesn't parse request body in GET and DELETE methods which seems fair. However you still can get raw body data(param1=foo&param2=bar when Content-Type: application/x-www-form-urlencoded).
2. Apache and Nginx webservers avoid underscores in HTTP headers, so api_key header received as api-key. Refs: Cannot retrieve all request headers using PHP slim framework and Why underscores are forbidden in HTTP header names. Maybe we should throw a warning in default generator when HTTP headers contains underscore?
3. Current template can't distinguish file parameter in file type with Content-Type: multipart/form-data and binary format with Content-Type: application/x-www-form-urlencoded. I'll try to fix it in future patches. Solved in [core] Set isMultipart=true for multipart operations, fix possible NPE #3750

Conclusion is that generator is ready to be reviewed and merged.

[wing328]

Maybe we should throw a warning in default generator when HTTP headers contains underscore?

I think there are configurable settings to make Apache/Nginx work properly with HTTP headers with underscore in the key name.

• https://stackoverflow.com/a/26938688/677735
• http://httpd.apache.org/docs/trunk/env.html#fixheader

I don't mind showing a warning/info message reminding users about this default limitations - maybe showing such message starting in the PHP Slim generator that you've been working on.

[wing328]

The php-slim4 generator has been included in the 4.2.0 release:

To generate PHP Slim4 server stub given an OpenAPI/Swagger specification file, please follow 3 simple steps below:

1. Download the Java JAR (http://central.maven.org/maven2/org/openapitools/openapi-generator-cli/4.2.0/openapi-generator-cli-4.2.0.jar)
2. Rename the JAR as "openapi-generator-cli.jar"
3. Run the following command to generate a PHP Slim4 server stub for the Petstore API (https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator/src/test/resources/2_0/petstore.yaml):

Mac/Linux:

• java -jar openapi-generator-cli.jar generate -g php-slim4 -i https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator/src/test/resources/2_0/petstore.yaml -o /var/tmp/php-slim4/

Windows:

• java -jar openapi-generator-cli.jar generate -g php-slim4 -i https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator/src/test/resources/2_0/petstore.yaml -o C:\tmp\php-slim4