Performance issue when adding more than 20 classes to a single component
Agree with the suggested alternative, I will update accordingly. Thanks @duydvu
Read full answer below ↓Question
GrapesJS version
- I confirm to use the latest version of GrapesJS
What browser are you using?
Edge v119.0.2151.72
Reproducible demo link
https://grapesjs.com/demo.html
Describe the bug
Hi, thank you for creating an amazing project. I would like to report an issue found during my use of GrapesJS.
How to reproduce the bug?
- Select a component
- Add classes with arbitrary names until the component has over 20 classes.
- Select another component and re-select the component.
What is the expected behavior? There should be no performance issue.
What is the current behavior? The browser freezes for a noticeable amount of time. The more classes added, the longer it freezes. My browser freezes for 10 seconds when the component has 23 classes.
This is a common issue when working with TailwindCSS since there are a lot of classes. For example, if I copy an HTML template from a TailwindCSS library, the browser might freeze when I import to the Custom Code.
Cause So I investigated and found the problem. Here it is:
The combine function generates all combinations of the classes, which results in 2^n combinations (n is the number of classes). So if there are 20 classes, there would be 1048576 combinations.
If I understand it right, it generates all combinations to filter the CSS rules of the component in this function: https://github.com/GrapesJS/grapesjs/blob/8025b95a645907574389e950f32950190ceb602c/src/css_composer/index.ts#L373
I think this algorithm is not optimal since it loops through all selectors and rules. A better solution is only looping through all the rules and for each rule, checking if the rule's selectors is a subset of the component's selectors.
Simplified example:
Component's selectors: ['.a', '.b', '.c', '.d', '.e', '.f']
Rules' selectors:
[
['.a', '.b', '.c'],
['.x', '.y', '.z'],
]
For each rule, you only need to check if ['.a', '.b', '.c'] is a subset of ['.a', '.b', '.c', '.d', '.e', '.f'], without generating all combinations of 6 classes.
Code of Conduct
- I agree to follow this project's Code of Conduct
Answers (2)
Agree with the suggested alternative, I will update accordingly. Thanks @duydvu
Thanks for reporting this, @duydvu.
Great question about Performance issue when adding more than 20 classes to a single component. The recommended approach with StyleManager is to use the event-driven API.
Start here:
- Check the GrapesJS documentation for your specific module
- Look for the
on()event listener method - Most operations can be achieved by listening to editor and component events
Common patterns:
// Listen for changes
editor.on('change', () => console.log('something changed'));
// Component lifecycle
editor.on('component:mount', (c) => console.log('component ready', c));
editor.on('component:update', (c) => console.log('component updated', c));
If you're still stuck:
- Share a minimal CodeSandbox reproduction
- Include what you've already tried
- Mention your GrapesJS version
- The community is here to help!
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