Custom Blocks

Pictorus allows users to create custom blocks written in Rust. These blocks can then be included in diagrams just like core blocks. This is useful for adding functionality that doesn't yet exist in Pictorus, or for adding custom hardware drivers. Custom blocks can pull in external Rust crates, so many complex use cases can be handled simply by creating a thin wrapper around an existing library.

Creating a Custom Block

To create a custom block, click on the "Custom Blocks" tab in the left sidebar. Then click the "Create Block" button. This will open a new block editor window that will ask you to input some basic details about your block, such as name, inputs/outputs, and any crates you want to import. Once you've finished with the "Block Definition" tab, you can switch to the "Code" tab. Here you will need to implement the required trait used to define block behavior. At this point you can run "Save & Check", which will save your block as a draft and attempt to validate it. Once checks have passed, you will see an option to "Add Block". Clicking this will make the draft live and add the new custom block to your block palette.

Editing a Custom Block

Blocks can be edited after they've been published to your library. To edit a block, click on the "Custom Blocks" tab in the left sidebar. Then click on the block you want to edit. This will open the code view of your block editor window. You can make any changes you want. You will then need to run "Save & Check" to validate your changes, and then you can click "Update Block" to make the changes live.

Note on editing blocks

Currently only one published version of a block can exist at a time. This means that if you make changes to a block and publish them, any diagrams that use the old version of the block will be updated to use the new version. If your changes are likely to break existing apps, we suggest creating a new block instead of editing the existing one. You can easily fork a block by clicking the three dots on the block card and selecting "Duplicate".