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v0.2.0 adding Promise & async/await support
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@erossignon erossignon released this 23 Jan 22:22
· 2476 commits to master since this release
v0.2.0
ab79cc0

Version 0.2.0 introduces a new way to call asynchronous methods on OPCUAClient and ClientSession objects

  • node style async method with callback
  • async method returning a Promise
    see article

Promised version can be chained more easily. They can also be used with async/await on nodeJS > 8 or Typescript (with ES2015 support enabled)

💔 Breaking changes:

some breaking changes have been necessary to normalize all async function and make sure they only provide a single output value. As such, old code using ClientSession#read, #read #browse #readVariableValue #readHistoryValue #readAllAttributes will have to be fixed.

Each OPCUAClient ClientSession async methods comes in two forms:

  • the first form allow multiple read/write/browse operation to be performed in a single operation.

example form1: reading many dataValue at once

var nodesToRead = [ 
 { nodeId:      "ns=2;s=Furnace_1.Temperature",attributeId: AttributeIds.Value},
 { nodeId:      "ns=2;s=Furnace_2.Temperature",attributeId: AttributeIds.Value}
];
session.read(nodesToRead,function(err,dataValues,diagnosticInfos) {
  if (!err) {
   dataValues.forEach(dataValue=>console.log(dataValue.toString()));
  }
});

or with the Promise version:

session.read(nodesToRead).then(function(dataValues) {
//...
});

or with the async/await version (node >8)

const dataValues = async session.read(nodesToRead); // an Array
  • the second form is used to read/write/browse a single element
    example form2: reading a single node
var nodeToRead = {
    nodeId:      "ns=2;s=Furnace_1.Temperature",
    attributeId: AttributeIds.BrowseName
};
session.read(nodeToRead,function(err,dataValue,diagnosticInfos) {
    if (!err) {
        console.log(dataValue.toString());
    }
});

or with the Promise version:

session.read(nodeToRead).then(function(dataValue) {
//...
});

or with the async/await version (node >8)

const dataValue = async session.read(nodeToRead);

🆕 new features:

  • updated typescript declaration file
  • add new async method extension for node 8 & above (896b323)
  • use thenify to provide Promise version of async methods (c18cdd4)
  • [Breaking Change] fix ClientSession#read callback parameters allow ClientSession#read #browse #readVariableValue #readHistoryValue #readAllAttributes to handle a single element or an array of element.
    #readAllAttributes now return json object with node attributes (649d0a8)

🐛 bug fixing

  • #413 fix wrong assert (c1afc23)
  • #416 fix certificate generation issue on MacOS and LibreSLL - use node-opcua-pki@0.0.29 (357823e)
  • add sample images for server simulation (98a29cd)
  • fix makeBrowsePath access (4f45ff3)

👬 contributors

  • @bompi88 for adding support for LibreSSL node-opcua-pki
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