Document Management System plugin for QGIS
What
A document management plugin to help managing relations between a document table and one or more feature tables.
Two example project demonstrating the usage of the plugin with different configurations are provided: Demo project
Configuration
Relations
Several relation scenarios are possible in a project involving a document table and in this documentation are referred this way:
- Normal Many to One: There is one document table and one feature table. The link is done with a foreign key field in the document table. Many documents can be linked with one feature. A document can be linked only with one feature. See the menu Project->Properties->Relations in the simple bees project bee_farming_normal_many_to_one_relation.qgs.
- Normal Many to Many: There is one document table, one feature table and one join table. The link is done with an entry in the join table which have two foreign keys columns: one for the document and one for the feature. In this setup many documents can be linked to many features and the opposite.
- Polymorphic Many to One: There is one document table and multiple feature tables (i.e. with points, lines, polygons, ...). The link is done with a set of many to one relations called Polymorphic relation and they consists of two columns in the document table: the Id of the feature and a QGIS expression pointing to the referenced feature table (layer). A document can be linked only with one feature.
- Polymorphic Many to Many: There is one document table, multiple feature tables and a join table. The link is done with an entry in the join table which have two columns for the Id of the document and of the feature and a third column with a QGIS expression pointing to the referenced feature table. In this setup many documents can be linked to many features from one or multiple layers. See the menu Project->Properties->Relations in the polymorphic bees project bee_farming_polymorphic_many_to_many_relation.qgs.
The relation/s between the Document table and the Feature/s table/s must be configured by hand in the usual way in Project -> Properties -> Relations. Please refer to the QGIS documentation for how to setup relations or polymorphic relations.
Document side
Widget type
Set to Document relation editor (Document side)
Relation to features
- Normal Many to Many
- Set cardinality to the final table
- Uncheck Polymorphic relation
- Polymorphic Many to Many
- Set cardinality to Many to one relation
- Check Polymorphic relation
- Select the right polymorphic relation with the selection box
Note: For the Many to One configurations the relation editor widgets are not available. The usual relation reference widget can be used in this context.
Feature side
Widget type
Set to Document relation editor (Feature side)
Relation to documents
- One to many: Set cardinality to Many to one relation
- Many to many: Set cardinality to the document table
Note: There is no distinction for polymorphic relation as from the feature point of view this are normal foreign key relations
Widget configuration
- Documents default path: An expression to the default path for documents. This is in most cases the same expression as for the attachment widget's default path in the documents table attribute form. For example
@project_folder || '/Documents' - Documents path field name: The name of the field containing the filename in the documents table.
Usage
Document side
Feature side
Installation notes:
The following QML modueles are required. On windows they are provided by the QGIS installation but on linux they may have to be installed manually:
| QML Module | Ubuntu package name |
|---|---|
| Qt quick controls | qml-module-qtquick-controls |
| Qt quick dialogs | qml-module-qtquick-dialogs |
| Qt quick layouts | qml-module-qtquick-layouts |