[Question] Previewing is depend on texlab or not?

[ROCKTAKEY]

Hi! Thanks for your maintenance!

I have question on the page https://texlab.netlify.app/docs/installation/previewing, for solving this issue.

Does the previewing depend on texlab? Or, is it just a function of VSCode extension?

Thanks.

[pfoerster]

Thank you for maintaining the Emacs plugin.

The previewing after building itself is just a latexmk configuration and does not depend on texlab.
However, the forward search does depend on texlab.
I am not sure how it is done for lsp-mode but most
clients allow you to pass configuration to texlab (in VSCode, this corresponds to settings.json) using either the workspace/configuration request or the workspace/didChangeConfiguration notification. The forward search itself is implemented as a custom request currently (see https://texlab.netlify.app/docs/reference/custom-messages for the details)
but we are going to convert it into a command (workspace/executeCommand) soon with the 3.0 release in order to stay more in line with the LSP spec.

Maybe this thread can help: emacs-lsp/lsp-mode#167.

[ROCKTAKEY]

I got it.
I will make attachment of this feature on Emacs.
Thanks a lot!

[ROCKTAKEY]

@pfoerster Could you help me if you don't mind?

After initialization, I send to texlab:

[Trace - 05:02:13 PM] Sending notification 'workspace/didChangeConfiguration'.
Params: {
  "settings": {
    "latex.forwardSearch.executable": "qpdfview",
    "latex.forwardSearch.args": [
      "--unique",
      "%p#src:%f:%l:1"
    ]
  }
}

Then, send:

[Trace - 05:32:24 PM] Sending request 'textDocument/forwardSearch - (1333)'.
Params: {
  "textDocument": {
    "uri": "file:///home/rocktakey/aaa.tex"
  },
  "position": {
    "line": 19,
    "character": 0
  }
}

Then, received:

[Trace - 05:32:24 PM] Received response 'textDocument/forwardSearch - (1333)' in 49ms.
Result: {
  "status": 3
}

Status 3 means unconfigured. The first configuration is bad? Or, status 3 means other error?

[pfoerster]

@ROCKTAKEY I think you need to send the settings like this:

"settings": {
    "latex": {
        "forwardSearch": {
            "executable": "qpdfview",
            "args": ["--unique", "%p#src:%f:%l:1"]
        }
    }
}

Otherwise, serde_json may not be able to deserialize the settings.

[ROCKTAKEY]

@pfoerster Thanks!
I changed to:

[Trace - 06:50:16 PM] Sending notification 'workspace/didChangeConfiguration'.
Params: {
  "settings": {
    "latex": {
      "forwardSearch": {
        "executable": "qpdfview",
        "args": [
           "--unique",
           "%p#src:%f:%l:1" 
        ]
      }
    }
  }
}

However, almost completely same response was received.

send:

[Trace - 06:50:19 PM] Sending request 'textDocument/forwardSearch - (1454)'.
Params: {
  "textDocument": {
    "uri": "file:///home/rocktakey/aaa.tex"
  },
  "position": {
    "line": 19,
    "character": 0
  }
}

received:

[Trace - 06:50:19 PM] Received response 'textDocument/forwardSearch - (1454)' in 48ms.
Result: {
  "status": 3
}

Are there any requirements or mistakes, yet?

[pfoerster]

This seems like a bug of texlab to me. Can you try running texlab with

texlab -vvvv --log-file texlab.log

and post the log here?

[ROCKTAKEY]

I tried it now, but it was failed. texlab gives error:

thread 'main' panicked at 'failed to open log file: Os { code: 2, kind: NotFound, message: "No such file or directory" }', src/main.rs:86:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

It seem to be another bug. It is my fault. I put --log-file ~/texlab.log but texlab cannot accept ~ omisstion

[ROCKTAKEY]

Sorry for my mistakes. Here is log file.
texlab.log

[pfoerster]

Thank you for the log. It seems that the issue is that the Emacs LSP client advertises the workspace/configuration request capability. texlab prefers using the workspace/configuration request instead of the workspace/didChangeConfiguration notification (mainly because of VSCode compability and I read once that workspace/configuration should be preferred). However, a lot of clients only support workspace/didChangeConfiguration so texlab supports both approaches. The problem is that texlab chooses the pull-based approach but the client always returns [null] when querying a configuration section so the options are not picked up.

So we have two options to fix the issue:

1. Do not advertise the workspace/configuration request capability (the easy way)
2. Support the workspace/configuration request properly (at the moment it always returns null)

[ROCKTAKEY]

I see.
Delete advertising is difficult, because it is hard-coded on our upstream.
So I will do latter one. I should make setting along with this, shouldn't I?

[pfoerster]

I should make setting along with this, shouldn't I?

Yeah, that would be pretty nice. Then, the user can use additional features like building on save or configuring the BibTeX formatter.

[ROCKTAKEY]

It works with workspace/configuration! Thanks a lot!

Now we can use all configuration of latex and bibtex.