How to create OutPutContext via V2 client library for node js - dialogflow-es

Question

I am working on entity and intents creation in my agent using v2 client library for node.js . And for that i am going through this sample which is on git. And it says something related to session id and context id. Can anyone explain me what is sessionId and contextId. And also provide me link where i can read those thing in details.
I am unable to create context by following those example. How can i create context while creating intent at the same time.

Answer 1

The following is code to create a context. You cannot create a context and an intent in a single API call, you first need to create the context and then create the intent that uses the context. The response to the create context API call will return a context ID you can use in your intent.
const dialogflow = require('dialogflow');
// Instantiates clients
const entityTypesClient = new dialogflow.EntityTypesClient();
// The path to the agent the created entity type belongs to.
const agentPath = entityTypesClient.projectAgentPath(projectId);
const createEntityTypeRequest = {
parent: agentPath,
entityType: {
displayName: displayName,
kind: kind,
},
};
entityTypesClient
.createEntityType(createEntityTypeRequest)
.then(responses => {
console.log(`Created ${responses[0].name} entity type`);
})
.catch(err => {
console.error('Failed to create size entity type:', err);
});
Source: https://github.com/googleapis/nodejs-dialogflow/blob/master/samples/resource.js

Answer 2

Contexts are very closely associated with SessionID. Say for eg, you have a chatbot that gets spun up on two computers serving two different user's. Each user will have a respective session_id (If you're coding in NODE, when a new user fires the chatbot, you need to ensure he/she will get a unique session_id).
Now, every unique session id will have unique contexts. From above example, let's say user 1 will initialize an intent that has input context named 'abc' with lifespan of 2 and user 2 will initialize another intent that has input context named 'xyz' with lifespan of 5, these respective contexts gets recorded against each of these user's individual session id's. You can programatically control (edit) contexts and its lifecycle. This is the biggest advantage of code facilitated Dialogflow as opposed to using GUI. Using services like Firebase, you can also preserve session id's and its associated contexts so, next time same user sign's in again, they can start from where they had last left.
I can share a snippet from one of my previous projects where I was managing contexts programatically. Initialization script is as follows:
/**
* #author Pruthvi Kumar
* #email pruthvikumar.123#gmail.com
* #create date 2018-08-15 04:42:22
* #modify date 2018-08-15 04:42:22
* #desc Dialogflow config for chatbot.
*/
const dialogflow_config = {
projectId: 'xxx',
sessionId: 'chatbot-session-id', //This is default assignment. This will hve to be overridden by sessionId as obtained from client in order to main context per sessionId.
languageCode: 'en-US'
};
exports.configStoreSingleton = (function () {
let instanceStacks;
let instanceSessionId;
let contextStack = {};
let intentsStack = {};
let successfulIntentResponseStack = {};
function init() {
contextStack[dialogflow_config['sessionId']] = [];
intentsStack[dialogflow_config['sessionId']] = [];
successfulIntentResponseStack[dialogflow_config['sessionId']] = [];
return {
contextStack: contextStack,
intentsStack: intentsStack,
successfulIntentResponseStack: successfulIntentResponseStack
};
}
return {
init: function () {
if (!instanceStacks || (instanceSessionId !== dialogflow_config['sessionId'] && (!intentsStack[dialogflow_config['sessionId']]))) {
console.log('[dialogflow_config]: Singleton is not instantiated previously or New userSession is triggered! Fresh instance stack will be provisioned');
instanceStacks = init();
instanceSessionId = dialogflow_config['sessionId'];
}
return instanceStacks;
}
};
})();
exports.updateSessionIdOfDialogflowConfig = function (sessionId) {
if (typeof (sessionId) === 'string') {
dialogflow_config['sessionId'] = sessionId;
return true;
} else {
console.warn('[dialogflow_config]: SessionId must be of type STRING!');
return;
}
};
exports.getDialogflowConfig = function () {
return dialogflow_config;
};
And then, to programmatically manage contexts:
/**
* #author Pruthvi Kumar
* #email pruthvikumar.123#gmail.com
* #create date 2018-08-15 04:37:15
* #modify date 2018-08-15 04:37:15
* #desc Operate on Dialogflow Contexts
*/
const dialogflow = require('dialogflow');
const dialogflowConfig = require('../modules/dialogflow_config');
const structjson = require('./dialogflow_structjson');
const util = require('util');
const contextsClient = new dialogflow.ContextsClient();
exports.setContextHistory = function (sessionId, intent_name, context_payload, preservedContext=false) {
/* maintain context stack per session */
/* context_payload = {input_contexts: [], output_contexts = []}
*/
const contextStack = dialogflowConfig.configStoreSingleton.init().contextStack;
if (intent_name) {
contextStack[sessionId].push({
intent: intent_name,
contexts: context_payload,
preserveContext: preservedContext
});
} else {
console.warn('[dialogflow_contexts]: Intent name is not provided OR Nothing in context_payload to add to history!');
}
};
exports.getContextHistory = function () {
const contextStack = dialogflowConfig.configStoreSingleton.init().contextStack;
return contextStack;
}
exports.preserveContext = function () {
const contextStack = dialogflowConfig.configStoreSingleton.init().contextStack;
//Traverse contextStack, get the last contexts.
let context_to_be_preserved = contextStack[dialogflowConfig.getDialogflowConfig()['sessionId']][contextStack[dialogflowConfig.getDialogflowConfig()['sessionId']].length - 1];
//console.log(`context to be preserved is: ${util.inspect(context_to_be_preserved)}`);
return context_to_be_preserved['contexts'].map((context, index) => {
let context_id = exports.getContextId(context);
return exports.updateContext(context_id, true)
});
}
From here, you can reference this github resource to build your own contexts - https://github.com/googleapis/nodejs-dialogflow/blob/master/samples/resource.js
Happy creating digital souls!