# Migration Guide: 9.7.4 → 9.8.0 Version **9.8.0** brings a new tool to add custom items to . This release is a breaking change for users who had configured `ext_css_list` or `ext_js_list`. --- ## Summary ### Added - New `setHeadElements`, `getHeadElements` and `addHeadElement` to `OConfig`. - Option to define global custom elements on application configuration via `head_elements`. ### Changed - Configuration options `ext_css_list` and `ext_js_list` will stop working. - These configuration options won't break the `Config.json` file, but they will be ignored. - New `head_elements` option added to `Config.json` file. ### Removed - Configuration options `ext_css_list` and `ext_js_list` will stop working. - These configuration options won't break the `Config.json` file, but they will be ignored. - `OConfig` methods `setExtCSSList`, `getExtCSSList`, `addExtCssList`, `setExtJSList`, `getExtJSList` and `addExtJsList` removed. --- ## Impact on Existing Projects Users who had `ext_css_list` or `ext_js_list` options defined on `Config.json` will have to change as they won't work anymore. For example: ```json { "ext_css_list": ["https://example.com/example.css"], "ext_js_list": ["https://example.com/example.js"] } ``` Will have to change to: ```json { "head_elements": [ { "item": "link", "attributes": { "rel": "stylesheet", "href": "https://example.com/example.css" } }, { "item": "script", "attributes": { "src": "https://example.com/example.js" } } ] } ``` --- ## Purpose of This Update This documentation update aims to: - Provide a global option to add custom elements to - Instead of having separate ways to add external CSS o JS files, now users will be capable of adding any kind of item: CSS, JS, meta tags, canonical links... --- ## Backward Compatibility Users with `ext_css_list` or `ext_js_list` will see those links stop working and are not loaded on their application. --- ## Developer Action Required If a user has `ext_css_list` or `ext_js_list`, they will have to update those to the new `head_elements` configuration option. --- ## Notes Future versions may reference this documentation baseline when introducing architectural or behavioral changes.