Merge pull request #430 from MerginMaps/iss_172-revert-to-old-version

revert to older version

src/manage/project-details.md

@@ -5,6 +5,7 @@ Each time someone synchronises the project from a mobile device or from QGIS thr
 
 On <AppDomainNameLink />, you can view what files have been added or removed. If you use GeoPackage for your survey, you can also see the list of the features which have been added, deleted or updated.
 
+
 :::tip
 Great tools to inspect the project history and compare changes between project versions can be found in the <QGISPluginNameShort />:
 - use [Create report](./plugin/#create-report-processing-toolbox) to get an overview of changes for a range of project versions.
@@ -25,6 +26,34 @@ To see the project history:
 
 ![Mergin Maps project history web](./web-history-2.jpg "Mergin Maps project history")
 
+:::tip
+Our blog [Downloading a previous version of your project](https://merginmaps.com/blog/support-tip-downloading-a-previous-version-of-your-project) contains detailed steps on how to download projects that are too large to be downloaded from the <DashboardShortLink />.
+:::
+
+
+### How to revert to an older version
+You may find yourself in a situation where you want to revert to an older version of the project.
+
+Local changes made in QGIS (changes that were not synchronised yet) can be reverted by using the **Reset changes** option in [Project status](./synchronisation/#synchronising-changes-in-qgis).
+
+To revert to an older version of a project (already synchronised to the cloud), you need to download it to your computer from the <DashboardShortLink />. Navigate to the [project history](#project-history) and find the version you want to use. [Advanced changelogs](#advanced-changelog) may be helpful. 
+
+**Download** the project version to your computer. Open the project in QGIS to make sure it is the version you want to restore.
+
+Now you have multiple options:
+- [Package the downloaded project version](./project/#packaging-qgis-project) as a new <MainPlatformName /> project. You can keep both projects if needed or [delete](./project-advanced/#delete-a-project) the one you don't need anymore.
+
+- Replace the specific files in your <MainPlatformName /> project folder:
+   1. Close QGIS
+   2. Copy the QGIS project (`.qgz`), the data (`.gpkg`) or both from the downloaded older version and paste them to your current [<MainPlatformName /> project folder](./project/#mergin-maps-project-folder). 
+
+      Be careful when doing this! If you changed the data schema between your versions, this might be a bit tricky. By replacing the QGIS project file, you will revert the project settings, such as symbology, forms settings, relations, etc. By replacing the data files, you will get the content that was saved in the downloaded version of the project.
+
+   3. Open the project in QGIS and check if you restored your project successfully. If needed, modify the project settings so that everything works as intended.
+
+   4. If you are happy with the result, synchronise the changes. The restored version is now the current version of your project.
+
+
 ## Advanced changelog
 To see more details of a specific version:
 1. Click on the version number you'd like to view the details