.. index:: Server plugins; Developing, Python; Developing server plugins
.. testsetup:: server
from qgis.core import (
QgsProject,
QgsRasterLayer,
QgsVectorLayer,
QgsApplication,
QgsDataSourceUri,
QgsLayerTreeLayer,
)
from qgis.server import (
QgsServerFilter,
QgsAccessControlFilter,
QgsServerCacheFilter,
)
.. only:: html
.. contents::
:local:
:depth: 3
To learn more about QGIS Server, read the :ref:`QGIS-Server-manual`.
QGIS Server is three different things:
- QGIS Server library: a library that provides an API for creating OGC web services
- QGIS Server FCGI: a FCGI binary application :file:`qgis_mapserv.fcgi` that together with a web server implements a set of OGC services (WMS, WFS, WCS etc.) and OGC APIs (WFS3/OAPIF)
- QGIS Development Server: a development server binary application :file:`qgis_mapserver` that implements a set of OGC services (WMS, WFS, WCS etc.) and OGC APIs (WFS3/OAPIF)
This chapter of the cookbook focuses on the first topic and by explaining the usage of QGIS Server API it shows how it is possible to use Python to extend, enhance or customize the server behavior or how to use the QGIS Server API to embed QGIS server into another application.
There are a few different ways you can alter the behavior of QGIS Server or extend its capabilities to offer new custom services or APIs, these are the main scenarios you may face:
EMBEDDING:menuselection:`-->` Use QGIS Server API from another Python applicationSTANDALONE:menuselection:`-->` Run QGIS Server as a standalone WSGI/HTTP serviceFILTERS:menuselection:`-->` Enhance/Customize QGIS Server with filter pluginsSERVICES:menuselection:`-->` Add a new SERVICEOGC APIs:menuselection:`-->` Add a new OGC API
Embedding and standalone applications require using the QGIS Server Python API directly from another Python script or application. The remaining options are better suited for when you want to add custom features to a standard QGIS Server binary application (FCGI or development server): in this case you'll need to write a Python plugin for the server application and register your custom filters, services or APIs.
The fundamental classes involved in a typical QGIS Server application are:
- :class:`QgsServer <qgis.server.QgsServer>` the server instance (typically a single instance for the whole application life)
- :class:`QgsServerRequest <qgis.server.QgsServerRequest>` the request object (typically recreated on each request)
- :meth:`QgsServer.handleRequest(request, response) <qgis.server.QgsServer.handleRequest>` processes the request and populates the response
The QGIS Server FCGI or development server workflow can be summarized as follows:
initialize the QgsApplication
create the QgsServer
the main server loop waits forever for client requests:
for each incoming request:
create a QgsServerRequest request
create a QgsServerResponse response
call QgsServer.handleRequest(request, response)
filter plugins may be executed
send the output to the client
Inside the :meth:`QgsServer.handleRequest(request, response) <qgis.server.QgsServer.handleRequest>` method the filter plugins callbacks are called and :class:`QgsServerRequest <qgis.server.QgsServerRequest>` and :class:`QgsServerResponse <qgis.server.QgsServerResponse>` are made available to the plugins through the :class:`QgsServerInterface <qgis.server.QgsServerInterface>` class.
Warning
QGIS server classes are not thread safe, you should always use a multiprocessing model or containers when building scalable applications based on QGIS Server API.
For standalone server applications or embedding, you will need to use the above mentioned server classes directly, wrapping them up into a web server implementation that manages all the HTTP protocol interactions with the client.
A minimal example of the QGIS Server API usage (without the HTTP part) follows:
from qgis.core import QgsApplication
from qgis.server import *
app = QgsApplication([], False)
# Create the server instance, it may be a single one that
# is reused on multiple requests
server = QgsServer()
# Create the request by specifying the full URL and an optional body
# (for example for POST requests)
request = QgsBufferServerRequest(
'http://localhost:8081/?MAP=/qgis-server/projects/helloworld.qgs' +
'&SERVICE=WMS&REQUEST=GetCapabilities')
# Create a response objects
response = QgsBufferServerResponse()
# Handle the request
server.handleRequest(request, response)
print(response.headers())
print(response.body().data().decode('utf8'))
app.exitQgis()Here is a complete standalone application example developed for the continuous integrations testing on QGIS source code repository, it showcases a wide set of different plugin filters and authentication schemes (not mean for production because they were developed for testing purposes only but still interesting for learning): :source:`qgis_wrapped_server.py <tests/src/python/qgis_wrapped_server.py>`
Server python plugins are loaded once when the QGIS Server application starts and can be used to register filters, services or APIs.
The structure of a server plugin is very similar to their desktop counterpart, a :class:`QgsServerInterface <qgis.server.QgsServerInterface>` object is made available to the plugins and the plugins can register one or more custom filters, services or APIs to the corresponding registry by using one of the methods exposed by the server interface.
Filters come in three different flavors and they can be instantiated by subclassing one of the classes below and by calling the corresponding method of :class:`QgsServerInterface <qgis.server.QgsServerInterface>`:
I/O filters can modify the server input and output (the request and the response) of the core services (WMS, WFS etc.) allowing to do any kind of manipulation of the services workflow. It is possible for example to restrict the access to selected layers, to inject an XSL stylesheet to the XML response, to add a watermark to a generated WMS image and so on.
From this point, you might find useful a quick look to the :pyqgis:`server plugins API docs <server>`.
Each filter should implement at least one of three callbacks:
- :meth:`onRequestReady() <qgis.server.QgsServerFilter.onRequestReady>`
- :meth:`onResponseComplete() <qgis.server.QgsServerFilter.onResponseComplete>`
- :meth:`onSendResponse() <qgis.server.QgsServerFilter.onSendResponse>`
All filters have access to the request/response object (:class:`QgsRequestHandler <qgis.server.QgsRequestHandler>`) and can manipulate all its properties (input/output) and raise exceptions (while in a quite particular way as we’ll see below).
All these methods return a boolean value indicating if the call should be propagated to the subsequent filters. If one of these method returns :const:`False` then the chain stop, otherwise the call will propagate to the next filter.
Here is the pseudo code showing how the server handles a typical request and when the filter’s callbacks are called:
for each incoming request:
create GET/POST request handler
pass request to an instance of QgsServerInterface
call onRequestReady filters
if there is not a response:
if SERVICE is WMS/WFS/WCS:
create WMS/WFS/WCS service
call service’s executeRequest
possibly call onSendResponse for each chunk of bytes
sent to the client by a streaming services (WFS)
call onResponseComplete
request handler sends the response to the client
The following paragraphs describe the available callbacks in details.
This is called when the request is ready: incoming URL and data have been parsed and before entering the core services (WMS, WFS etc.) switch, this is the point where you can manipulate the input and perform actions like:
- authentication/authorization
- redirects
- add/remove certain parameters (typenames for example)
- raise exceptions
You could even substitute a core service completely by changing SERVICE parameter and hence bypassing the core service completely (not that this make much sense though).
This is called whenever any partial output is flushed from response buffer (i.e to FCGI stdout
if the fcgi server is used) and from there, to the client.
This occurs when huge content is streamed (like WFS GetFeature). In this case
:meth:`onSendResponse() <qgis.server.QgsServerFilter.onSendResponse>` may be called multiple times.
Note that if the response is not streamed, then :meth:`onSendResponse() <qgis.server.QgsServerFilter.onSendResponse>` will not be called at all.
In all case, the last (or unique) chunk will be sent to client after a call to :meth:`onResponseComplete() <qgis.server.QgsServerFilter.onResponseComplete>`.
Returning :const:`False` will prevent flushing of data to the client. This is desirable when a plugin wants to collect all chunks from a response and examine or change the response in :meth:`onResponseComplete() <qgis.server.QgsServerFilter.onResponseComplete>`.
This is called once when core services (if hit) finish their process and the request is ready to be sent to the client. As discussed above, this method will be called before the last (or unique) chunk of data is sent to the client. For streaming services, multiple calls to :meth:`onSendResponse() <qgis.server.QgsServerFilter.onSendResponse>` might have been called.
:meth:`onResponseComplete() <qgis.server.QgsServerFilter.onResponseComplete>` is the ideal place to provide new services implementation (WPS or custom services) and to perform direct manipulation of the output coming from core services (for example to add a watermark upon a WMS image).
Note that returning :const:`False` will prevent the next plugins to execute :meth:`onResponseComplete() <qgis.server.QgsServerFilter.onResponseComplete>` but, in any case, prevent response to be sent to the client.
Some work has still to be done on this topic: the current implementation can distinguish between handled and unhandled exceptions by setting a :class:`QgsRequestHandler <qgis.server.QgsRequestHandler>` property to an instance of QgsMapServiceException, this way the main C++ code can catch handled python exceptions and ignore unhandled exceptions (or better: log them).
This approach basically works but it is not very "pythonic": a better approach would be to raise exceptions from python code and see them bubbling up into C++ loop for being handled there.
.. index:: server plugins; metadata.txt, metadata, metadata.txt
A server plugin is a standard QGIS Python plugin as described in :ref:`developing_plugins`, that just provides an additional (or alternative) interface: a typical QGIS desktop plugin has access to QGIS application through the :class:`QgisInterface <qgis.gui.QgisInterface>` instance, a server plugin has only access to a :class:`QgsServerInterface <qgis.server.QgsServerInterface>` when it is executed within the QGIS Server application context.
To make QGIS Server aware that a plugin has a server interface, a special metadata entry is needed (in :file:`metadata.txt`):
server=True
Important
Only plugins that have the server=True metadata set will be loaded and executed by QGIS Server.
The qgis3-server-vagrant example plugin discussed here (with many more) is available on github, a few server plugins are also published in the official QGIS plugins repository.
Plugin filesHere's the directory structure of our example server plugin.
PYTHON_PLUGINS_PATH/
HelloServer/
__init__.py --> *required*
HelloServer.py --> *required*
metadata.txt --> *required*
.. index:: Plugins; metadata.txt, Metadata__init__.py
This file is required by Python's import system. Also, QGIS Server requires that this file contains a :func:`serverClassFactory()` function, which is called when the plugin gets loaded into QGIS Server when the server starts. It receives reference to instance of :class:`QgsServerInterface <qgis.server.QgsServerInterface>` and must return instance of your plugin's class. This is how the example plugin :file:`__init__.py` looks like:
.. testcode:: server
def serverClassFactory(serverIface):
from .HelloServer import HelloServerServer
return HelloServerServer(serverIface)
HelloServer.py
This is where the magic happens and this is how magic looks like: (e.g. :file:`HelloServer.py`)
A server plugin typically consists in one or more callbacks packed into instances of a :class:`QgsServerFilter <qgis.server.QgsServerFilter>`.
Each :class:`QgsServerFilter <qgis.server.QgsServerFilter>` implements one or more of the following callbacks:
- :meth:`onRequestReady() <qgis.server.QgsServerFilter.onRequestReady>`
- :meth:`onResponseComplete() <qgis.server.QgsServerFilter.onResponseComplete>`
- :meth:`onSendResponse() <qgis.server.QgsServerFilter.onSendResponse>`
The following example implements a minimal filter which prints HelloServer! in case the SERVICE parameter equals to “HELLO”:
.. testcode:: server
class HelloFilter(QgsServerFilter):
def __init__(self, serverIface):
super().__init__(serverIface)
def onRequestReady(self) -> bool:
QgsMessageLog.logMessage("HelloFilter.onRequestReady")
return True
def onSendResponse(self) -> bool:
QgsMessageLog.logMessage("HelloFilter.onSendResponse")
return True
def onResponseComplete(self) -> bool:
QgsMessageLog.logMessage("HelloFilter.onResponseComplete")
request = self.serverInterface().requestHandler()
params = request.parameterMap()
if params.get('SERVICE', '').upper() == 'HELLO':
request.clear()
request.setResponseHeader('Content-type', 'text/plain')
# Note that the content is of type "bytes"
request.appendBody(b'HelloServer!')
return True
The filters must be registered into the serverIface as in the following example:
.. testcode:: server
class HelloServerServer:
def __init__(self, serverIface):
serverIface.registerFilter(HelloFilter(serverIface), 100)
The second parameter of :meth:`registerFilter() <qgis.server.QgsServerInterface.registerFilter>` sets a priority which defines the order for the callbacks with the same name (the lower priority is invoked first).
By using the three callbacks, plugins can manipulate the input and/or the output of the server in many different ways. In every moment, the plugin instance has access to the :class:`QgsRequestHandler <qgis.server.QgsRequestHandler>` through the :class:`QgsServerInterface <qgis.server.QgsServerInterface>`. The :class:`QgsRequestHandler <qgis.server.QgsRequestHandler>` class has plenty of methods that can be used to alter the input parameters before entering the core processing of the server (by using :func:`requestReady`) or after the request has been processed by the core services (by using :func:`sendResponse`).
The following examples cover some common use cases:
Modifying the inputThe example plugin contains a test example that changes input parameters coming
from the query string, in this example a new parameter is injected into the
(already parsed) parameterMap, this parameter is then visible by core services
(WMS etc.), at the end of core services processing we check that the parameter
is still there:
.. testcode:: server
class ParamsFilter(QgsServerFilter):
def __init__(self, serverIface):
super(ParamsFilter, self).__init__(serverIface)
def onRequestReady(self) -> bool:
request = self.serverInterface().requestHandler()
params = request.parameterMap( )
request.setParameter('TEST_NEW_PARAM', 'ParamsFilter')
return True
def onResponseComplete(self) -> bool:
request = self.serverInterface().requestHandler()
params = request.parameterMap( )
if params.get('TEST_NEW_PARAM') == 'ParamsFilter':
QgsMessageLog.logMessage("SUCCESS - ParamsFilter.onResponseComplete")
else:
QgsMessageLog.logMessage("FAIL - ParamsFilter.onResponseComplete")
return True
This is an extract of what you see in the log file:
src/core/qgsmessagelog.cpp: 45: (logMessage) [0ms] 2014-12-12T12:39:29 plugin[0] HelloServerServer - loading filter ParamsFilter
src/core/qgsmessagelog.cpp: 45: (logMessage) [1ms] 2014-12-12T12:39:29 Server[0] Server plugin HelloServer loaded!
src/core/qgsmessagelog.cpp: 45: (logMessage) [0ms] 2014-12-12T12:39:29 Server[0] Server python plugins loaded
src/mapserver/qgshttprequesthandler.cpp: 547: (requestStringToParameterMap) [1ms] inserting pair SERVICE // HELLO into the parameter map
src/mapserver/qgsserverfilter.cpp: 42: (onRequestReady) [0ms] QgsServerFilter plugin default onRequestReady called
src/core/qgsmessagelog.cpp: 45: (logMessage) [0ms] 2014-12-12T12:39:29 plugin[0] SUCCESS - ParamsFilter.onResponseCompleteOn the highlighted line the “SUCCESS” string indicates that the plugin passed the test.
The same technique can be exploited to use a custom service instead of a core one: you could for example skip a WFS SERVICE request or any other core request just by changing the SERVICE parameter to something different and the core service will be skipped. Then you can inject your custom results into the output and send them to the client (this is explained below).
Tip
If you really want to implement a custom service it is recommended to subclass :class:`QgsService <qgis.server.QgsService>` and register your service on :meth:`registerFilter() <qgis.server.QgsServerInterface.serviceRegistry>` by calling its :meth:`registerService(service) <qgis.server.QgsServiceRegistry.registerService>`
The watermark filter example shows how to replace the WMS output with a new image obtained by adding a watermark image on the top of the WMS image generated by the WMS core service:
.. testcode:: server
from qgis.server import *
from qgis.PyQt.QtCore import *
from qgis.PyQt.QtGui import *
class WatermarkFilter(QgsServerFilter):
def __init__(self, serverIface):
super().__init__(serverIface)
def onResponseComplete(self) -> bool:
request = self.serverInterface().requestHandler()
params = request.parameterMap( )
# Do some checks
if (params.get('SERVICE').upper() == 'WMS' \
and params.get('REQUEST').upper() == 'GETMAP' \
and not request.exceptionRaised() ):
QgsMessageLog.logMessage("WatermarkFilter.onResponseComplete: image ready %s" % request.parameter("FORMAT"))
# Get the image
img = QImage()
img.loadFromData(request.body())
# Adds the watermark
watermark = QImage(os.path.join(os.path.dirname(__file__), 'media/watermark.png'))
p = QPainter(img)
p.drawImage(QRect( 20, 20, 40, 40), watermark)
p.end()
ba = QByteArray()
buffer = QBuffer(ba)
buffer.open(QIODevice.WriteOnly)
img.save(buffer, "PNG" if "png" in request.parameter("FORMAT") else "JPG")
# Set the body
request.clearBody()
request.appendBody(ba)
return True
In this example the SERVICE parameter value is checked and if the incoming request is a WMS GETMAP and no exceptions have been set by a previously executed plugin or by the core service (WMS in this case), the WMS generated image is retrieved from the output buffer and the watermark image is added. The final step is to clear the output buffer and replace it with the newly generated image. Please note that in a real-world situation we should also check for the requested image type instead of supporting PNG or JPG only.
Access control filters gives the developer a fine-grained control over which layers, features and attributes can be accessed, the following callbacks can be implemented in an access control filter:
- :meth:`layerFilterExpression(layer) <qgis.server.QgsAccessControlFilter.layerFilterExpression>`
- :meth:`layerFilterSubsetString(layer) <qgis.server.QgsAccessControlFilter.layerFilterSubsetString>`
- :meth:`layerPermissions(layer) <qgis.server.QgsAccessControlFilter.layerPermissions>`
- :meth:`authorizedLayerAttributes(layer, attributes) <qgis.server.QgsAccessControlFilter.authorizedLayerAttributes>`
- :meth:`allowToEdit(layer, feature) <qgis.server.QgsAccessControlFilter.allowToEdit>`
- :meth:`cacheKey() <qgis.server.QgsAccessControlFilter.cacheKey>`
Here's the directory structure of our example plugin:
PYTHON_PLUGINS_PATH/
MyAccessControl/
__init__.py --> *required*
AccessControl.py --> *required*
metadata.txt --> *required*
__init__.py
This file is required by Python's import system. As for all QGIS server plugins, this file contains a :func:`serverClassFactory()` function, which is called when the plugin gets loaded into QGIS Server at startup. It receives a reference to an instance of :class:`QgsServerInterface <qgis.server.QgsServerInterface>` and must return an instance of your plugin's class. This is how the example plugin :file:`__init__.py` looks like:
.. testcode:: server
def serverClassFactory(serverIface):
from MyAccessControl.AccessControl import AccessControlServer
return AccessControlServer(serverIface)
AccessControl.py
.. testcode:: server
class AccessControlFilter(QgsAccessControlFilter):
def __init__(self, server_iface):
super().__init__(server_iface)
def layerFilterExpression(self, layer):
""" Return an additional expression filter """
return super().layerFilterExpression(layer)
def layerFilterSubsetString(self, layer):
""" Return an additional subset string (typically SQL) filter """
return super().layerFilterSubsetString(layer)
def layerPermissions(self, layer):
""" Return the layer rights """
return super().layerPermissions(layer)
def authorizedLayerAttributes(self, layer, attributes):
""" Return the authorised layer attributes """
return super().authorizedLayerAttributes(layer, attributes)
def allowToEdit(self, layer, feature):
""" Are we authorised to modify the following geometry """
return super().allowToEdit(layer, feature)
def cacheKey(self):
return super().cacheKey()
class AccessControlServer:
def __init__(self, serverIface):
""" Register AccessControlFilter """
serverIface.registerAccessControl(AccessControlFilter(serverIface), 100)
This example gives a full access for everybody.
It's the role of the plugin to know who is logged on.
On all those methods we have the layer on argument to be able to customise the restriction per layer.
Used to add an Expression to limit the results.
For example, to limit to features where the attribute role is equal to user.
.. testcode:: server
def layerFilterExpression(self, layer):
return "$role = 'user'"
Same than the previous but use the SubsetString (executed in the database)
For example, to limit to features where the attribute role is equal to user.
.. testcode:: server
def layerFilterSubsetString(self, layer):
return "role = 'user'"
Limit the access to the layer.
Return an object of type :meth:`LayerPermissions() <qgis.server.QgsAccessControlFilter.layerPermissions>`, which has the properties:
- :attr:`canRead <qgis.server.QgsAccessControlFilter.LayerPermissions.canRead>`
to see it in the
GetCapabilitiesand have read access. - :attr:`canInsert <qgis.server.QgsAccessControlFilter.LayerPermissions.canInsert>` to be able to insert a new feature.
- :attr:`canUpdate <qgis.server.QgsAccessControlFilter.LayerPermissions.canUpdate>` to be able to update a feature.
- :attr:`canDelete <qgis.server.QgsAccessControlFilter.LayerPermissions.canDelete>` to be able to delete a feature.
For example, to limit everything on read only access:
.. testcode:: server
def layerPermissions(self, layer):
rights = QgsAccessControlFilter.LayerPermissions()
rights.canRead = True
rights.canInsert = rights.canUpdate = rights.canDelete = False
return rights
Used to limit the visibility of a specific subset of attribute.
The argument attribute return the current set of visible attributes.
For example, to hide the role attribute:
.. testcode:: server
def authorizedLayerAttributes(self, layer, attributes):
return [a for a in attributes if a != "role"]
This is used to limit the editing on a subset of features.
It is used in the WFS-Transaction protocol.
For example, to be able to edit only feature that has the attribute role
with the value user:
.. testcode:: server
def allowToEdit(self, layer, feature):
return feature.attribute('role') == 'user'
QGIS Server maintains a cache of the capabilities then to have a cache
per role you can return the role in this method. Or return None
to completely disable the cache.
In QGIS Server, core services such as WMS, WFS and WCS are implemented as subclasses of :class:`QgsService <qgis.server.QgsService>`.
To implement a new service that will be executed when the query string parameter SERVICE matches the service name,
you can implement your own :class:`QgsService <qgis.server.QgsService>`
and register your service on the :meth:`serviceRegistry() <qgis.server.QgsServerInterface.serviceRegistry>`
by calling its :meth:`registerService(service) <qgis.server.QgsServiceRegistry.registerService>`.
Here is an example of a custom service named CUSTOM:
.. testcode:: server
from qgis.server import QgsService
from qgis.core import QgsMessageLog
class CustomServiceService(QgsService):
def __init__(self):
QgsService.__init__(self)
def name(self):
return "CUSTOM"
def version(self):
return "1.0.0"
def executeRequest(self, request, response, project):
response.setStatusCode(200)
QgsMessageLog.logMessage('Custom service executeRequest')
response.write("Custom service executeRequest")
class CustomService():
def __init__(self, serverIface):
serverIface.serviceRegistry().registerService(CustomServiceService())
In QGIS Server, core OGC APIs such OAPIF (aka WFS3) are implemented as collections of :class:`QgsServerOgcApiHandler <qgis.server.QgsServerOgcApiHandler>` subclasses that are registered to an instance of :class:`QgsServerOgcApi <qgis.server.QgsServerOgcApi>` (or it's parent class :class:`QgsServerApi <qgis.server.QgsServerApi>`).
To implement a new API that will be executed when the url path matches a certain URL, you can implement your own :class:`QgsServerOgcApiHandler <qgis.server.QgsServerOgcApiHandler>` instances, add them to an :class:`QgsServerOgcApi <qgis.server.QgsServerOgcApi>` and register the API on the :meth:`serviceRegistry() <qgis.server.QgsServerInterface.serviceRegistry>` by calling its :meth:`registerApi(api) <qgis.server.QgsServiceRegistry.registerApi>`.
Here is an example of a custom API that will be executed when the URL contains /customapi:
.. testcode:: server
import json
import os
from qgis.PyQt.QtCore import QBuffer, QIODevice, QTextStream, QRegularExpression
from qgis.server import (
QgsServiceRegistry,
QgsService,
QgsServerFilter,
QgsServerOgcApi,
QgsServerQueryStringParameter,
QgsServerOgcApiHandler,
)
from qgis.core import (
QgsMessageLog,
QgsJsonExporter,
QgsCircle,
QgsFeature,
QgsPoint,
QgsGeometry,
)
class CustomApiHandler(QgsServerOgcApiHandler):
def __init__(self):
super(CustomApiHandler, self).__init__()
self.setContentTypes([QgsServerOgcApi.HTML, QgsServerOgcApi.JSON])
def path(self):
return QRegularExpression("/customapi")
def operationId(self):
return "CustomApiXYCircle"
def summary(self):
return "Creates a circle around a point"
def description(self):
return "Creates a circle around a point"
def linkTitle(self):
return "Custom Api XY Circle"
def linkType(self):
return QgsServerOgcApi.data
def handleRequest(self, context):
"""Simple Circle"""
values = self.values(context)
x = values['x']
y = values['y']
r = values['r']
f = QgsFeature()
f.setAttributes([x, y, r])
f.setGeometry(QgsCircle(QgsPoint(x, y), r).toCircularString())
exporter = QgsJsonExporter()
self.write(json.loads(exporter.exportFeature(f)), context)
def templatePath(self, context):
# The template path is used to serve HTML content
return os.path.join(os.path.dirname(__file__), 'circle.html')
def parameters(self, context):
return [QgsServerQueryStringParameter('x', True, QgsServerQueryStringParameter.Type.Double, 'X coordinate'),
QgsServerQueryStringParameter(
'y', True, QgsServerQueryStringParameter.Type.Double, 'Y coordinate'),
QgsServerQueryStringParameter('r', True, QgsServerQueryStringParameter.Type.Double, 'radius')]
class CustomApi():
def __init__(self, serverIface):
api = QgsServerOgcApi(serverIface, '/customapi',
'custom api', 'a custom api', '1.1')
handler = CustomApiHandler()
api.registerHandler(handler)
serverIface.serviceRegistry().registerApi(api)