#chairo
chairo ("happy" in ancient Greek) is a Seneca micro-services plugin for hapi. The plugin integrates the Seneca functionality into hapi and provide tools to map its actions to server methods and views for easy access.
Lead Maintainer - Eran Hammer
chairo is registered with a hapi server using the server.register() method. Once
registered it decorates the server object with a reference to the seneca object initialized
using the provided plugin options:
var Chairo = require('chairo');
var Hapi = require('hapi');
var server = new Hapi.Server();
server.connection();
// Pass options to the Seneca constructor
var senecaOptions = { log: 'silent' };
// Register plugin
server.register({ register: Chairo, options: senecaOptions }, function (err) {
// Add a Seneca action
var id = 0;
server.seneca.add({ generate: 'id' }, function (message, next) {
return next(null, { id: ++id });
});
// Invoke a Seneca action
server.seneca.act({ generate: 'id' }, function (err, result) {
// result: { id: 1 }
});
});In addition, the hapi request object is decorated with a reference to the seneca object for
easy access:
server.route({
method: 'POST',
path: '/id',
handler: function (request, reply) {
// Invoke a Seneca action using the request decoration
request.seneca.act({ generate: 'id' }, function (err, result) {
if (err) {
return reply(err);
}
return reply(result);
});
}
});Maps a Seneca action pattern to a hapi server method where:
name- the server method name (same as the name used inserver.method()).pattern- the Seneca action pattern (e.g.'generate:id'or{ generate: 'id' }) to map.options- optional settings options where:cache- method caching options (same as the name used inserver.method()).
var Chairo = require('chairo');
var Hapi = require('hapi');
var server = new Hapi.Server();
server.connection();
server.register(Chairo, function (err) {
// Set up a Seneca action
var id = 0;
server.seneca.add({ generate: 'id' }, function (message, next) {
return next(null, { id: ++id });
});
// Map action to a hapi server method
server.action('generate', 'generate:id', { cache: { expiresIn: 1000 } });
// Start hapi server (starts cache)
server.start(function () {
// Invoke server method
server.methods.generate(function (err, result1) {
// Invoke the same server method
server.methods.generate(function (err, result2) {
// result1 === result2 (cached)
});
});
});
});Sends back a handler response using the result of a Seneca action where:
pattern- the Seneca action called to generate the response.
var Chairo = require('chairo');
var Hapi = require('hapi');
var server = new Hapi.Server();
server.connection();
server.register(Chairo, function (err) {
// Set up a Seneca action
var id = 0;
server.seneca.add({ generate: 'id' }, function (message, next) {
return next(null, { id: ++id });
});
// Add route
server.route({
method: 'POST',
path: '/id',
handler: function (request, reply) {
// Reply using a Seneca action
return reply.act({ generate: 'id' });
}
});
});In addition, the act handler shortcut is also provided:
server.route({
method: 'POST',
path: '/id',
handler: { act: 'generate:id' }
});Renders a template view using the provided template and context where:
template- the view engine template (same as the name used inreply.view()).context- the context object used to render the template where each top level key with a$suffix is assigned the corresponding Seneca action matching the key's value pattern.options- optionals settings passed toreply.view().
var Chairo = require('chairo');
var Handlebars = require('handlebars');
var Hapi = require('hapi');
var server = new Hapi.Server();
server.connection();
server.register(Chairo, function (err) {
// set up a few Seneca actions
server.seneca.add({ lookup: 'date' }, function (message, next) {
return next(null, { date: (new Date()).toString() });
});
server.seneca.add({ load: 'user' }, function (message, next) {
return next(null, { name: message.name });
});
// Set up a hapi view engine
server.views({
engines: { html: Handlebars },
path: __dirname + '/templates'
});
// Add route
server.route({
method: 'GET',
path: '/',
handler: function (request, reply) {
// Setup context with both Seneca actions and simple keys
var context = {
today$: 'lookup:date', // Using string pattern
user$: { load: 'user', name: 'john' }, // Using object pattern
general: {
message: 'hello!'
}
};
// Reply with rendered view
return reply.compose('example', context);
}
});
});Using the template ./templates/example.html:
<div>
<h1>{{today$.date}}</h1>
<h2>{{user$.name}}</h2>
<h3>{{general.message}}</h3>
</div>In addition, the compose handler shortcut is also provided:
server.route({
method: 'POST',
path: '/id',
handler: {
compose: {
template: 'example',
context: {
today$: 'lookup:date',
user$: { load: 'user', name: 'john' },
general: {
message: 'hello!'
}
}
}
}
});