QSA REST API : /api/projects

Project

A QSA project is defined by:

• a QGIS project
• a list of themes
• an internal SQLite database
• a MapProxy configuration file (if enabled)

Examples:

# create a project and store the QGIS project in PostgreSQL within `my_schema`
$ curl "http://localhost/api/projects/" \
     -X POST \
     -H 'Content-Type: application/json' \
     -d '{
        "name":"my_project",
        "author":"pblottiere",
        "schema":"my_schema"
     }'

# get metadata about the project stored in PostgreSQL
$ curl "http://localhost/api/projects/my_project?schema=my_schema"

Layer

When a layer is added/removed to a QSA project, the corresponding QGIS project is updated. When MapProxy cache management is enabled, the configuration file is updated as well and the cache may be cleaned if necessary (for example when the current style is updated).

Several themes can be associated with a layer like in QGIS Desktop, but only the current one is used when the STYLE parameter in OGC web services is empty.

Layer definition

A layer can be added to a project thanks to the next parameters:

• type : raster or vector
• name : the layer’s name
• datasource : the link to the datasource according to the storage backend
  • filesystem : /tmp/raster.tif
  • AWS S3 : /vsis3/bucket/raster.tif
  • PostGIS : service=qsa table=\"public\".\"lines\" (geom)
• overview (optional) : automatically build overviews for raster layers stored in S3 buckets
• crs (optional) : CRS (automatically detected by default)

Example:

# Add a FlatGeobuf vector layer stored on S3 bucket in project `my_project`
$ curl "http://localhost/api/projects/my_project/layers" \
  -X POST \
  -H 'Content-Type: application/json' \
  -d '{
    "name":"my_layer",
    "type":"vector",
    "datasource":"/vsis3/my-storage/vector/my_layer.fgb"
  }'

Style

A QSA style may be used through the STYLE OGC web services parameter to specify the rendering for a specific layer. Default styles may be defined and automatically used when a vector layer is added to a QSA project.

Vector style

For vector layers, a style can be defined with the parameters listed below:

• type : vector
• name : the name of the style
• rendering : rendering parameters (only opacity is supported for now)
• symbology : dictionary with type (only single_symbol is supported for now), symbol and properties

Example:

# Add a style for point geometry vector layers
$ curl "http://localhost:5000/api/projects/my_project/styles" \
  -X POST \
  -H 'Content-Type: application/json' \
  -d '{
    "type": "vector",
    "name": "my_marker_style",
    "rendering": {
      "opacity": 100.
    },
    "symbology": {
      "type": "single_symbol",
      "symbol": "marker",
      "properties": {
        "color": "#112233"
      }
    }
  }'

To set a default style for a specific geometry, the parameters listed below are available:

• name : the name of the style to use by default
• geometry : the geometry for which the style needs to be applied

Raster style

For raster layers, a style can be defined with the parameters listed below:

• type : raster
• name : the name of the style
• rendering : rendering parameters
• symbology : dictionary with type (only singlebandgray and multibandcolor are supported for now) and properties

Example:

# Add a style for multiband raster
$ curl "http://localhost:5000/api/projects/my_project/styles" \
  -X POST \
  -H 'Content-Type: application/json' \
  -d '{
    "type": "raster",
    "name": "my_multiband_style",
    "rendering": {
      "saturation": 3,
      "brightness": -148,
      "contrast": 42,
      "gamma": 4.
    },
    "symbology": {
      "type": "multibandcolor",
      "properties": {
        "red": {
          "band": 1
        },
        "green": {
          "band": 2
        },
        "blue": {
          "band": 3
        }
      }
    }
  }'

Cache

Example:

$ curl "http://localhost:5000/api/projects/my_project/cache"
{
  "valid":true,
  "storage":"filesystem"
}