Create a session for a notebook

createsession.ts

import {
  INotebookSession, IKernelSpecIds, ContentsManager, startNewSession,
  getKernelSpecs
} from 'jupyter-js-services';


/**
 * Fetch notebook contents by path.
 */
export
function fetchNotebook(path: string, baseUrl?: string, ajaxSettings?: string): Promise<any> {
  let contentsManager = new ContentsManager(baseUrl, ajaxSettings);
  return contentsManager.get(path, { type: 'notebook'} ).then(contents => {
    return contents.content;
  });
}

/**
 * Create an appropriate notebook session for a given path.
 */
export
function createSession(notebookPath: string, content: any, baseUrl?: string, ajaxSettings?: string): Promise<INotebookSession> {
  let metadata = content.metadata;
  let name = metadata.kernelspecs ? metadata.kernelspecs.name : 'unknown';
  let lang = metadata.language_info ? metadata.language_info.name : 'unknown';
  return getKernelSpecs({ baseUrl, ajaxSettings }).then(specs => {
    let kernelName = findKernel(name, lang, specs);
    return startNewSession({ kernelName, notebookPath, baseUrl, ajaxSettings });
  });
}


/**
 * Get the appropriate kernel name given a notebook model.
 */
function findKernel(kernelName: string, language: string, specs: IKernelSpecIds): string {
  if (kernelName === 'unknown') {
    return specs.default;
  }
  // Look for an exact match.
  for (let specName in specs.kernelspecs) {
    if (specName === kernelName) {
      return kernelName;
    }
  }
  // Next try to match the language name.
  if (language === 'unknown') {
    return specs.default;
  }
  for (let specName in specs.kernelspecs) {
    let kernelLanguage = specs.kernelspecs[name].spec.language;
    if (language === kernelLanguage) {
      console.log('No exact match found for ' + name +
                  ', using kernel ' + specName + ' that matches ' +
                  'language=' + language);
      return specName;
    }
  }
  // Finally, use the default kernel.
  console.log(`No matching kernel found for ${kernelName}, ` +
              `using default kernel ${specs.default}`);
  return specs.default;
}

Use as:

fetchNotebook('foo').then(content => {
  createSession('foo', content).then(session => {
    let code = content.cells[0].source;
    let request = {
      code,
      silent: false,
      store_history: true,
      stop_on_error: true,
      allow_stdin: true
    };
    session.kernel.execute(request);
  });
});

Use as: ...

Shouldn't fetchNotebook be called with at least path and baseUrl? So should be something like:

fetchNotebook('foo.ipynb', 'localhost:8888').then(content => {
  createSession('foo.ipynb', content,  'localhost:8888').then(session => {
    let code = content.cells[0].source;
    let request = {
      code,
      silent: false,
      store_history: true,
      stop_on_error: true,
      allow_stdin: true
    };
    session.kernel.execute(request);
  });
});

FYI, there's a typo in https://gist.github.com/blink1073/ac460d8cc9911d77d82b6d7862f06c55#file-createsession-ts-L24

content.metdata -> content.metadata

:)

If you don't provide a baseUrl, it will try and find it through the standard means.