Editing

This section describes how to set up feature editing in c2cgeoportal applications.

Just like most administrative tasks setting up editing in a c2cgeoportal application involves intervening in the database, through the c2cgeoportal administration interface.

Requirements

To be editable a layer should satisfy the following requirements:

  1. It should be accessible with WMS, and correctly configured in the mapfile. See Mapfile configuration.

  2. Its data should be in a PostGIS table, which should be in the application database. The PostGIS table can be in a separate schema though, which is even recommended.

  3. The PostGIS table should include a primary key with a sequence associated. Example:

    db=# \d table;
                     Table "public.table"
    Column   |      Type   |                              Modifiers
-------------+-------------+----------------------------------------------------------
 id          | integer     | not null default nextval('public.table_id_seq'::regclass)

  4. The PostGIS table should include one geometry column only. You will get errors if the table has multiple geometry columns, even if one of them only is declared in PostGIS’ geometry_columns table.

  5. The PostGIS table’s geometry column should be declared in PostGIS’ geometry_columns table. c2cgeoportal indeed queries the geometry_columns table to get the information it needs.

    Note

    Creating a geometry column and populating geometry_columns is typically done using the AddGeometryColumn function. The Populate_Geometry_Columns function can also be useful for registering already created geometry columns in geometry_columns.

    Note

    The following geometry types are supported: POINT, LINESTRING, POLYGON The following geometry types are partially supported: MULTIPOINT, MULTILINESTRING, MULTIPOLYGON

  6. If the PostGIS table has a many-to-one relationship to another table (typically a dictionary table) there are additional requirements:

    • The name of the foreign key column should end with _id (e.g. type_id). This is not strictly required, but recommended.
    • The relationship’s target table should have two columns, a primary key column and a text column. The text column must be named name.

Adding or making layers editable

The application’s layers are defined in the layer table, which is managed by selecting the Layers item in the admin interface’s menu.

For a layer to be editable its geoTable field should be set. This field is the name of the PostGIS table containing the layer’s geographic data. It is string of the form [<schemaname>.]<tablename>. If schemaname is omitted the table is assumed to be in the public schema. The label corresponding to this field is Related Postgres table in the admin interface.

Warning

Only layers embedded in a layergroup are detected as editable.

Warning

It is recommended to limit the editing to 30 editable layers per user.

Configuring security

Editing the features of a layer implies to write changes in the database. To make sure that only authorized users may edit a feature, editable layers (including public layers) must be linked to a restriction area, used itself to specify the roles of authorized users.

The restriction area should have its readwrite field set to true in the administration interface.

Note

  • By default a restriction areas has its readwrite field set to false.
  • A restriction area whose readwrite field is true applies to both read and write operations.

Binding restriction areas and layers together can be done from either the Restriction Area objects or the Layer objects in the admin interface. Likewise for binding roles and restriction areas.

Enabling Copy to functionality (CGXP only)

In the edit interface, you can give the user the possibility to copy features from one layer (source layer) to another layer (destination layer).

In the admin interface, open the UI metadatas list and add a new record:

  • Name: Select copy_to.
  • Value: Enter the list of choices for destination layer, as mapserver layer names, separated by commas.
  • Item: Select the source layer.

Example:

  • Name: copy_to
  • Value: polygon2,polygon3,polygon4
  • Item: polygon

Note

  • Source and destination layers must have the same geometry type.
  • Only the geometry will be copied, the attributes will not be.

Edit views

To be able to edit PostgreSQL views a primary key must be manually configured. Add a layer metadata geotablePrimaryKey with value the name of the column to use as primary key. That column must be of type Integer.

Example:

  • geotablePrimaryKey: id

Enable snapping

To be able to snap while editing, the snappingConfig must be set on the layer metadata. The value is a json object containing the following optional properties:

  • edge (boolean): whether to allow snapping on edges or not;
  • vertex (boolean): whether to allow snapping on vertices or not;
  • tolerance (number): the pixel tolerance.