Files
ionic-framework/packages/angular
Shane 344a43feca feat(infinite-scroll): adding preserveRerenderScrollPosition property (#30566)
Issue number: resolves internal

---------

<!-- Please do not submit updates to dependencies unless it fixes an
issue. -->

<!-- Please try to limit your pull request to one type (bugfix, feature,
etc). Submit multiple pull requests if needed. -->

## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

Currently, if you use infinite scroll and fully change out elements in
the DOM, you'll lose your scroll position. This can present as a race
condition in some frameworks, like React, but will present pretty
consistently in vanilla JavaScript. This happens because the browser is
removing the old elements from the DOM and adding the new ones, and
during that time the container holding the old elements will shrink and
the browser will adjust the top position to be the maximum of the new
container height.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

With this new property (`preserveRerenderScrollPosition`) set, we will
loop through siblings of the infinite scroll and set their min-heights
to be their current heights before triggering the `ionInfinite` event,
then we clean up after complete is called by restoring their previous
min-heights or setting them to auto if there were none. This prevents
the container from resizing and the browser from losing the scroll
position.

## Does this introduce a breaking change?

- [ ] Yes
- [X] No

<!--
  If this introduces a breaking change:
1. Describe the impact and migration path for existing applications
below.
  2. Update the BREAKING.md file with the breaking change.
3. Add "BREAKING CHANGE: [...]" to the commit description when merging.
See
https://github.com/ionic-team/ionic-framework/blob/main/docs/CONTRIBUTING.md#footer
for more information.
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## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

**Current dev build**: 
```
8.6.6-dev.11753719591.13a5c65f
```
2025-07-30 10:23:00 -07:00
..
2025-07-16 19:53:16 +00:00
2025-07-16 19:53:16 +00:00

@ionic/angular

Ionic Angular specific building blocks on top of @ionic/core components.

License

Testing Local Ionic Framework with ng add

This guide shows you how to test the local Ionic Framework build with a new Angular application using ng add. This is useful for development and testing changes before publishing.

Prerequisites

  • Node.js and npm installed
  • Angular CLI installed globally (npm install -g @angular/cli)

Build Local Ionic Framework

  1. Clone the repository (if not already done):

    git clone https://github.com/ionic-team/ionic-framework.git
    cd ionic-framework
    
  2. Pull the latest from main

    git pull origin main
    
  3. Install dependencies and build the core package:

    cd core
    npm install
    npm run build
    
  4. Install dependencies, sync the core build and build the Angular package:

    cd ../packages/angular
    npm install
    npm run sync
    npm run build
    
  5. Create a tarball:

    cd dist
    npm pack
    
  6. Copy the tarball to Downloads:

    cp ionic-angular-*.tgz ~/Downloads/ionic-angular.tgz
    

Test with New Angular App

  1. Create a new Angular app:

    # Change to whichever directory you want the app in
    cd ~/Documents/
    ng new my-app --style=css --ssr=false --zoneless=false
    cd my-app
    
  2. Install the local @ionic/angular package:

    npm install ~/Downloads/ionic-angular.tgz
    
  3. Run ng add:

    ng add @ionic/angular --skip-confirmation
    
  4. Serve the app:

    ng serve
    

The local Ionic Framework build is now active in the Angular app. Changes to the Ionic source code require rebuilding the packages and reinstalling the tarball to see updates.

Project Structure

common

This is where logic that is shared between lazy loaded and standalone components live. For example, the lazy loaded IonPopover and standalone IonPopover components extend from a base IonPopover implementation that exists in this directory.

Note: This directory exposes internal APIs and is only accessed in the standalone and src submodules. Ionic developers should never import directly from @ionic/angular/common. Instead, they should import from @ionic/angular or @ionic/angular/standalone.

standalone

This is where the standalone component implementations live. It was added as a separate entry point to avoid any lazy loaded logic from accidentally being pulled in to the final build. Having a separate directory allows the lazy loaded implementation to remain accessible from @ionic/angular for backwards compatibility.

Ionic developers can access this by importing from @ionic/angular/standalone.

src

This is where the lazy loaded component implementations live.

Ionic developers can access this by importing from @ionic/angular.