pip-services3-commons-node
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Portable abstractions and patterns for Pip.Services in Node.js
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JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
/** @module commands */
/** @hidden */
var _ = require('lodash');
var InvocationException_1 = require("../errors/InvocationException");
/**
* Concrete implementation of [[ICommand ICommand]] interface. Command allows to call a method
* or function using Command pattern.
*
* ### Example ###
*
* let command = new Command("add", null, (correlationId, args, callback) => {
* let param1 = args.getAsFloat("param1");
* let param2 = args.getAsFloat("param2");
* let result = param1 + param2;
* callback(null, result);
* });
*
* command.execute(
* "123",
* Parameters.fromTuples(
* "param1", 2,
* "param2", 2
* ),
* (err, result) => {
* if (err) console.error(err);
* else console.log("2 + 2 = " + result);
* }
* );
*
* // Console output: 2 + 2 = 4
*
* @see [[ICommand]]
* @see [[CommandSet]]
*/
var Command = /** @class */ (function () {
/**
* Creates a new command object and assigns it's parameters.
*
* @param name the command name.
* @param schema the schema to validate command arguments.
* @param func the function to be executed by this command.
*/
function Command(name, schema, func) {
if (!name)
throw new Error("Name cannot be null");
if (!func)
throw new Error("Function cannot be null");
this._name = name;
this._schema = schema;
if (!_.isFunction(func))
this._function = func.execute;
else
this._function = func;
if (!_.isFunction(this._function))
throw new Error("Function doesn't have function type");
}
/**
* Gets the command name.
* @returns the name of this command.
*/
Command.prototype.getName = function () {
return this._name;
};
/**
* Executes the command. Before execution it validates [[Parameters args]] using
* the defined schema. The command execution intercepts exceptions raised
* by the called function and returns them as an error in callback.
*
* @param correlationId (optional) transaction id to trace execution through call chain.
* @param args the parameters (arguments) to pass to this command for execution.
* @param callback function to be called when command is complete
*
* @see [[Parameters]]
*/
Command.prototype.execute = function (correlationId, args, callback) {
if (this._schema) {
try {
this._schema.validateAndThrowException(correlationId, args);
}
catch (ex) {
callback(ex, null);
return;
}
}
try {
this._function(correlationId, args, callback);
}
catch (ex) {
var err = new InvocationException_1.InvocationException(correlationId, "EXEC_FAILED", "Execution " + this.getName() + " failed: " + ex).withDetails("command", this.getName()).wrap(ex);
callback(err, null);
}
};
/**
* Validates the command [[Parameters args]] before execution using the defined schema.
*
* @param args the parameters (arguments) to validate using this command's schema.
* @returns an array of ValidationResults or an empty array (if no schema is set).
*
* @see [[Parameters]]
* @see [[ValidationResult]]
*/
Command.prototype.validate = function (args) {
if (this._schema)
return this._schema.validate(args);
return [];
};
return Command;
}());
exports.Command = Command;
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