snap-fileio / extension

This is the Snap! File I/O Extension, a loadable JavaScript extension for the Snap! visual programming environment that enables Snap! programs to read and write files on the local filesystem via a Node.js middleware server.

The extension registers 13 primitives (8 plain-text, 4 structured data, 1 error reporter) and injects a "File I/O" block category into the Snap! palette. It communicates with the middleware over HTTP REST, targeting any server that implements the API contract.

The extension is consumed by snap-out, which provides the Electron shell, Express server, and workspace configuration.

Blocks

Commands

| Block | Description | |---|---| | write %path content %content | Create or overwrite a text file | | append %content to %path | Append text to a file | | delete file %path | Delete a file | | create directory %path | Create a directory | | write CSV %path data %data delimiter %delim | Write list-of-lists as CSV | | write JSON %path data %data | Write Snap! data as JSON |

Reporters

| Block | Returns | |---|---| | read file %path | String | | read lines of %path | List of strings | | list files in %path | List of entry names | | file %path exists | Boolean | | read CSV %path delimiter %delim | List of lists | | read JSON %path | Snap! data (objects as list-of-pairs) | | last error | Error message string, or empty |

Building

The extension is bundled into a single IIFE file for browser loading:

npm run build

Output: dist/snap-fileio-extension.js

Testing

npm test

License

The Snap! File I/O extension is free software. You may redistribute and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License along with this program. If not, see https://www.gnu.org/licenses/.