Merge pull request #407 from opengisch/manage_conflicts

Added Conflicts Page

documentation/reference/qfieldcloud/conflicts.en.md

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+---
+title: Manage Conflicts
+tx_slug: documentation_reference_qfieldcloud_manage_conflicts
+---
+
+## Understanding Conflicts in Data Synchronization
+
+Conflicts occur when any of these conditions is met:
+
+1) distinct users set the same attribute on the same feature to different values;
+2) a primary key is employed twice.
+While highly unlikely have conflicts, preventing, mitigating and resolving conflicts is important to maintain data integrity in a healthy QGIS project. Here are some tips and tricks to do just that.
+
+### How to Avoid Conflicts?
+
+1. **Unique "fid" Serial Numbers:**
+   - When creating a feature, it is recommended to assign a unique "fid" serial number to each feature in the layers.
+   - Use the expression "epoch(now())" (without the double quote) in the "fid" to generate a unique identifier per millisecond, reducing the possibility of duplicate "fid" numbers.
+
+2. **Planning and Designation:**
+   - For updating existing features based on field conditions, plan and designate the features each user will update.
+   - Users should avoid changing the "fid" or identifier numbers.
+
+### How to Resolve Conflicts?
+
+- By default, QFieldCloud overwrites conflicts using a _last wins_ policy (the latest patch of changes to the attribute(s) involved in the conflict replaces all earlier patches of changes to these attributes). Alternatively, admins can set a project's conflict resolution policy to _manual_. Doing so will require the project manager to manually resolve conflicts, picking those to be applied to the project.
+
+- When dealing with conflicts:
+   - Navigate to the "Changes" section.
+   - Filter the changes with the "Not_applied" status.
+   - For each conflicted change, select it and set the status to "Re-apply" from the "Action" dropdown menu, alternatively if all the new changes are in conflict you can choose in the last conflicted change and select "Re-apply this and newer changes".
+   - Check the details of changes in the conflict and click "Save All" at the end of the page.
+   - Refer to our official documentation [Delta apply](https://docs.qfield.org/reference/qfieldcloud/jobs/#delta-apply-delta_apply-job) for additional information.
+
+!![](../../assets/images/resolving_conflicts.gif)