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This demo shows how to use FME Server to perform real time edits on a spatial database.Using WebSockets we ensure that any edits made to the dataset are instantaneously made available to everyone else looking at the data.The aim of the demo is to show how easy it is to build real time simple GIS editing application with FME Server without having to write any server-side code.
There are two components to the 亚搏在线workflow.The entire contents of the database are streamed to the map on page load.Then whenever the user make edits to the features,the contents of the edits are sent back to FME Server which makes the updates to the database and then streams the changes back to anyone who has the application open.
The page sends an empty message through a web socket (real_time_drawing_on_page_load_in) to the server.The socket is then closed.When the server receives the message,a workspace that is subscribed to the topic is run once.The workspace reads the database features and sends them through another socket (real_time_drawing_on_page_load_out).Page creates polygons and closes the socket.
So whenever a message is sent to the real_time_drawing_on_page_load_in topic via web sockets,the workspace will be run which sends the features back to the browser via the real_time_drawing_on_page_load_out stream.
This is done by a workspace that uses a WebsocketReceiver (runs indefinitely,tying down one engine).When an edit (Insert,update,delete) is received,it is parsed and the geometry part is converted from GeoJson to WKT,then a SQLExecutor runs the SQL query and gets the affected row's id (needed after an insert,as we want the clients to have a unique id for the new item).The workspace then broadcasts the message back through another socket and the web applications update the items they are showing.
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Receiving email,Part 1: Setting up a topic and an email address (2015)
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Weather Updates and FME Server (Tutorial)
Receiving email,Part 3: Using email attachments (2015)
Workspace Notifications,Part 1: From within the workspace (2015)
FME Server as a WebHook for littleBits
Take a photo,email it to FME Server and put it on the map
Sending email,Part 3: Sending an email when a workspace completes (2015)
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