Set language when opening new editor

[d-akara]

The new feature is working great. Thanks!
After using this for a bit, I found a couple of things that improve my work.

1. I set the language automatically when opening a new editor. I wanted to do this also for reusing the same editor, but I couldn't find an API to do it.
2. Included request url and elapsed time in the response document
3. Made the response information into comments which makes it play nice with the language theme and coloring.

Hopefully you can consider these changes. Thanks!

[Huachao]

@dakaraphi the code LGTM. However, I still want to discuss with you that do we give user the flexibility that user can view the response in http language and not commented headers and request url?

[d-akara]

@Huachao so are you simply asking to provide a user preference setting?
Something like rest-client.previewResponseSetUntitledDocumentLanguageByContentType

• default false: Will work as it did without my changes
• true: will attempt to set language and make header info comments

I added 2 additional pieces of information. The request url and response time. Do you want that included when in http format or only when language can be set?

[Huachao]

@dakaraphi that's what I mean, what do you think about it? And thanks for your PR

[d-akara]

@Huachao I added 2 new preferences. Let me know what you think.
For now, I have them both set as default false.

I do think setting the language adds a lot of power and makes the experience richer.

1. I can now use my theme created for custom coloring in response
2. I can now use all language feature extensions like JSON query or XML Xpath directly on the response. This is pretty cool.

If vscode resolves microsoft/vscode#1800 it will make it even better :-)

[Huachao]

add a space before :

[Huachao]

also indicate that this only works when previewing response in untitled document

[Huachao]

@dakaraphi Merged, I will publish this change in next release. Thanks for your contribution 😄

[Download]

microsoft/vscode#1800 looks resolved.

[Huachao]

@Download @dakaraphi thanks, I've changed to use the latest setTextDocumentLanguage API.

[Huachao]

@Download @dakaraphi I have published the new version 0.20.3 with this new setTextDocumentLanguage API