The user can define nodes, train runs, along with their routes and attributes to create a comprehensive Netzgrafik. The Netzgrafik undergoes multiple changes during editing. Each time it is modified, a new temporary version is created. Once the user publishes the latest version, all intermediate versions are removed, and the new version is permanently stored.
If the user wants different variants to study, he can duplicate any version to create a new independently editable variant within the project. When working on different projects, it is recommended that the user creates a separate project for each project. This allows for separate management of associated variants to each project.
To create a new project, simply click on the "+" symbol and enter a name, an abstract, and a short description. Now you have created a first project that can contain multiple variants.
29-01-2024-001-Create_new_project.webm
To create a new variant of a project, simply click on the "+" symbol and enter a name. As soon as you have created a new variant in the project, the editor will open automatically.
29-01-2024-002-create_new_variant.webm
The editor opens the newly created Netzgrafik. The new Netzgrafik contains some initially created nodes from which users can draw trainruns with their sections. In most projects these nodes are not required. If so press (ctrl+a) to select all elements of the current Netzgrafik and press 'delete' to remove them.
29-01-2024-003-clear_variant_data.webm
For mor details have a look into create and modifiy nodes.
For mor details have a look into create and modifiy trainrun.
The data model for the basic concept of Project/Variants includes the following entities:
-
Project: This entity represents a project. It contains information such as the project name, project description, and other project-related data, such as users identifiers with read or write access.
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Variant: This entity represents a variant within a project. It contains information such as the variant name and description.
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Version: This entity represents a version within a variant. Versions are used to store the change history and preserve intermediate changes during the creative process. They allow users to restore any previous version if needed.
The relationship between the entities is as follows:
erDiagram
Project o|--|{ Variant : has
Variant o|--|{ Version : has
A user has to publish a version of a variant when he is ready with editing/creating the variant. Only publish version becomes visible to all other users with access rights. Until the version is published, the full version history remains available.
When a user publishes a version, the intermediate versions between the last published version and the new published version are removed.
This information is specific to the internal context of SBB and may need to be adapted for other organizations.
Read and write access to projects and underlying variants is restricted to a certain group of people. For this purpose, the table "projects_users" maintains a list of users (identified by their user id) for each project. Only the listed users have access to the project. Users with the "is_editor" flag have write access to the project. Users without the flag have read access by default. Any user with the "User" role is allowed to create a new project. The creator of a project is automatically granted write access to the project.
Users with the "Admin" role have access to all projects regardless of the "projects_users" table.
Every Netzgrafik project requires one or more variant studies. The following graphic illustrates the conceptual structure of project and variant management in the Netzgrafik-Editor:
Conceptual structure of project and variant management - example
This implemented concept makes it possible to manage several planning projects. Several variants can be created for each planning project. Different versions can be created separately for each variant that corresponds to a Netzgrafik.
Based on a main version, several different users can create their own snapshot versions in parallel. However, only one user at a time can create a new main version.
All other user changes that are made later lead to an editing conflict. All editing conflicts must be resolved manually. An editing conflict can be resolved with the following three options:
- By overwriting the previously published version (active enforcement required)
- By creating a new variant (branch)
- By deleting the changes by accepting the published version.
Step-by-step example
| Version | Snapshot version | Author | Comments |
|---|---|---|---|
| - | 1 | u123 | Initial empty network diagram that is automatically created when creating the variant. |
| - | 2 | u123 | First modification by user u123. |
| - | 3 | u123 | Second modification by user u123. |
| - | 4 | u123 | ... |
| - | 5 | u123 | ... |
| 1 | 6 | u123 | Main version "1" has been published by user u123. Other users can now see the network diagram. |
| 1 | 1 | u123 | User u123 makes further changes based on main version "1". |
| 1 | 2 | u123 | ... |
| 1 | 1 | u456 | User u456 also opens main version "1" in parallel and makes changes. |
| 1 | 2 | u456 | ... |
| 1 | 3 | u456 | ... |
| 1 | 2 | u456 | User u456 is the first to publish the new main version "2" based on their modifications. |
| 2 | 3 | u123 | User u123 also wants to publish their modifications as main version "2" => editing conflicts ! |
| Alternatively, user u123 can save their modifications as a new variant. |
Deletion is primarily enabled through the following detour. The variants within a project can be archived and will only appear if explicitly requested to display them. The same applies to projects. Projects and variants can only be deleted from the archive. Therefore, no variant or project can be deleted directly. It must always be moved to the archive first. From the archive, the variant or project can be deleted or restored, i.e., the archiving can be undone. This logic is intended to prevent projects or variants from being accidentally deleted.
If a project is deleted, all of its variants will also be deleted.
It is important to understand that the projects and variants are available to all users with read or write access. The snapshot versions are only visible to the respective editing user and are no longer available to the user after publication (saving) since they are automatically deleted after successful publishing.