Custom Controls

Lesson 6: Sending and Receiving Data

Things to keep in mind:

The server and client communicate with each other using a uniform data structure
- Complex data is serialized to a WebValueTree
- A WebValueTree is a recursive array of keys and values
- Upon being received, the data can be deserialized back to a struct
- Any simple parameters sent along with the data can be sent as strings
On the server side – (de)serializing
- First, define the structs
- Then use the value tree struct tWebValueTree
  - ValueTreeSerializeParameter: serialize any struct
  - ValueTreeDeserializeParameter: deserializes any WebValueTree back to a struct
- To send data, add an extra optional parameter to the DataFlex code
- To receive the data from the client on the server, use the ptActionData property to get the data in DataFlex
- Server - code example of sending data…
- Server – code example for receiving data…
On the client side – (de)serializing
Use the df.sys.vt library
Define the structure using JavaScript objects
To deserialize a value tree use
df.sys.vt.deserialize(tVT, tDef);
To serialize an object to a value tree use
df.sys.vt.serialize(tDataObj);
Alternatively, generate a reusable (de)serializer
serializeMyDataVT:
df.sys.vt.generateSerializer(tDataObj),

deSerializeMyDataVT:
df.sys.vt.generateDeserializer(tDataObj),
This method is more efficient whenever calls need to be repeated
Client side – sending data
To send data from the client to the server an extra optional parameter needs to be added to the JavaScript call
To receive the data back in JavaScript use
this._tActionData
Client – code example of sending data
Client – code example of receiving data

Custom Controls

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Custom Controls

Lesson 6: Sending and Receiving Data

Things to keep in mind: