Getting only selected/marked text/code from a cell possible?

vdw · June 10, 2025, 1:11am

I have a simple extension that get the complete content of a selected markdown cell.

Is it possible to get/extract only the parts in a markdown or code cell that are selected/marked?

krassowski · June 10, 2025, 9:35am

Yes. I recall jupyter-ai does this here:

packages/jupyter-ai/src/selection-watcher.ts

4387ed2bb


      
          /**
           * Gets a Selection object from a document widget. Returns `null` if unable.
           */
          function getTextSelection(widget: Widget | null): Selection | null {
            const editor = getEditor(widget);
            // widget type check is redundant but hints the type to TypeScript
            if (!editor || !(widget instanceof DocumentWidget)) {
              return null;
            }
          
            let cellId: string | undefined = undefined;
            if (widget.content instanceof Notebook) {
              cellId = widget.content.activeCell?.model.id;
            }
          
            const selectionObj = editor.getSelection();
            let { start, end } = selectionObj;
            const startOffset = editor.getOffsetAt(start);
            const endOffset = editor.getOffsetAt(end);
            const text = editor.model.sharedModel

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Also, core JupyterLab search extracts selection when populating search box on Ctrl + F, the diff of this PR will show you two ways to do that: Uses the browser window's selection as the default search query by JasonWeill · Pull Request #15834 · jupyterlab/jupyterlab · GitHub

vdw · June 12, 2025, 1:41pm

Cool, thanks so much! I simply couldn’t find my way through the docs to solve this.

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Getting only selected/marked text/code from a cell possible?

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