Task extension

[marcdumais-work]

Tasks

This extension provides the means to execute scripts or executables on the backend, from a frontend client. Events are sent from the backend to the frontend client(s), when a task execution is started (includes task id, underlying process id, other runtime info) and finished (includes exit code, signal received). It's also possible for a frontend client to ask the backend for the list of tasks that are currently running.

We support having multiple frontend task clients that are using the same backend task server. Each client uses its workspace root as context parameter, in all its communications with the backend. Whenever the backend sends notifications to its clients, the original client context is sent along. It's then up-to the clients to determine if they are interested in the event, given its context, and show it to the user or not.

This mechanism makes it possible for multiple clients, opened on the same workspace, to all get the notifications related to all tasks that execute from that workspace. At the same time, clients can ignore tasks that are run from another workspace.

Task Frontend:

task-service

Contains the means for the Task frontend to communicate with the Task backend (server).

UI Contributions

• a "Run Task" command was added. It's available from a top-level "Task" menu as well as in the command palette. When triggered, it presents the list of known tasks configurations to the user, using the "quick open" list. Upon a task being chosen from there, a request is sent to execute that task, in the backend. When the execution is finished, the task backend sends an event, containing the exit code and signal. ATM that information is shown to the user as a FE notification.

note: If a task is configured as a "terminal" task, a terminal is opened when the task is run, showing its output. Else if the task is "raw", no terminal is started.

• a "Attach to Task" command was added. With this command, it's possible, from a frontend client, to connect to a (terminal-process-based) task that is executing in the backend, and show its output in a terminal.

task-configurations

A frontend client can have a workspace open. A workspace can have tasks defined in a file: <workspace root>/.theia/tasks.json

The TaskConfigurations class provides the task service with an up-to-date list of task configurations, that are available to execute at that moment, in the currently opened workspace . Then it watches the task configuration file for changes and re-parses it when it changes (e.g. after the user has edited it).

Here's a sample task configuration entry:

     {
        "label": "Test task - list workspace files recursively",
        "processType": "terminal",
        "cwd": "$workspace",
        "processOptions": {
            "command": "ls",
            "args": [
                "-alR"
            ]
        },
        "windowsProcessOptions": {
            "command": "cmd.exe",
            "args": [
                "/c",
                "dir",
                "/s"
            ]
       }
    }

We support using a symbolic $workspace value as part of the "cwd" field. This value is replaced by the value of the frontend's current workspace root directory, in the Task client, before sending the task configuration for execution, to the Task Server.

For some tasks, it might be possible to have the same task configuration, for different platforms. But in other cases, there might be some tweaks that need to be done, specially for the Windows platform. This is supported by having the windowsProcessOptions entry, that overrides the processOptions, on Windows, if present. See example above.

See extension's README.md for more details about task configurations.

Task Backend:

task-server

The Task server is a singleton, that can run and kill tasks. It doesn't know or care directly about which workspace a client has opened. Rather, a task configuration to be executed is expected to contain all required information, either by having an absolute path to the command to execute, or having that command found in the system path or in the configured Task's current working directory ("cwd").

task-manager

The Task Manager is a singleton that keeps track of all tasks that are being executed, in a given task backend. Tasks can be optionally accessed by client context, for e.g. easy lookup of running tasks for a given context.

[hexa00]

Did you mean to create a pull request with this ?
I see one commit but I guess this is not a PR yet...?

[marcdumais-work]

@hexa00 PR #690 created!

[svenefftinge]

Just came across this. Might contain some good ideas / experiences microsoft/vscode#15179

[vilashProgrammr]

this doesn't work in my case .
I have creates the task.json file in work-space still runtask doesn't show any tasks to run.

[marcdumais-work]

Hi @vilashProgrammr ,

Look here for more recent documentation about Tasks.