Logic Libraries

When you write rules using JavaScript, you will often benefit from using pre-existing libraries. A pre-existing library can be a JavaScript or Java library. API Creator includes a standard set of libraries. Logic libraries are JavaScript files of re-usable solutions for patterns. There is no limit to the number of libraries an API can use.

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Add a JavaScript Library to an API

You can add only JavaScript libraries to your API using API Creator. After you have added a library to your API, you can use its facilities in your rules by invoking classes and methods directly from JavaScript.

Best Practice:
There is cost in CPU and memory associated with each library that you make available. Select only those libraries your API will use.

With your API open, go to the Create, API Properties, Libraries, Your libraries tab, and click Create New Library
.

The Logic library window opens.

Complete the following fields and then save your changes:

Name

Enter a name for your library.

Code

Find your JavaScript library by clicking Choose File
, find and select your JavaScript library, and then clicking Open
.

The Logic library window closes.

Enable/activate the library inside your API by selecting the Used
checkbox and then save your changes.

The library is added to your API.

Add a Java Library to CA Live API Creator

You can leverage JAR files in your APIs. Before you start API Server, copy your Java JAR files into the following directory:

(The self-contained, single user version of CA Live API Creator based on Jetty) The

caliveapicreator/

lib/ext

directory.

(Tomcat) The

omcat/apache-tomcat-<version>/

lib

directory.

For more information about Tomcat installations, including how to leverage JAR files in APIs, see Install on Apache Tomcat.

If you have installed CA Live API Creator as a Docker container, see the information about how to load libraries at container startup in Install as a Docker Container.

Define the Available Libraries

The JavaScript libraries for your API are displayed on the Create, API Properties, Libraries, System libraries tab. The first few libraries listed on this tab are selected and available by default. You cannot clear the Used
checkbox for those libraries. You can make the other libraries listed available to JavaScript event programming and use them in JavaScript logic by selecting the Used
checkbox for those libraries. For example, many APIs use date arithmetic. The

Moment.js

library is a JavaScript date library for parsing, validating, manipulating, and formatting dates. You can make this library available inside your API.

Best Practice:
There is cost in CPU and memory associated with each library you make available. Select only those libraries your API will use.

Reload an Updated Library

If you update your library code, you must reload it.

With your API open, go to the Create, API Properties, Libraries, Your libraries tab, and click Change
for the revised library.The Logic Library dialog opens.

Click Choose File
, select your altered code, and save your changes.

Load Libraries: B2B sendEmail Function Example

The following JavaScript code snippet in the B2B Derby NW API shows the

sendEmail

JavaScript wrapper function. This function can call out to Java or other services:

Screen Shot 2016-11-21 at 7.07.11 PM.png

Call Libraries from Event Rules

The following is a commit event in the Business to Business example. This commit event is on the Orders object for the Insert operation:

var salesRep = row.EmployeeID; // object model (row) provides accessors to related objectsif (salesRep !== null) {  var mail = B2B.sendEmail(); // this is a loadable library  var config = {    to: '[email protected]', // better, find this from DB    from: '[email protected]',    title: 'Congratulations on your new Order',    text: 'An order was placed for you, totaling ' + row.AmountTotal  };  mail.configure(config);  var msg = mail.send();  logicContext.logDebug('Sending Mail - msg: ' + msg);}

For more information about how to call reusable solutions from rules, see the Business to Business Example.

You can avoid the configure call using a simpler approach. This useful pattern for initializing libraries is illustrated in the Business to Business example.

Load Libraries: moment.js Library Example

In this example, you have a table called Orders, with two attributes:

order_date

and

shipping_date

. You would like to have a computed attribute called

processing_delay

showing the time elapsed between these two dates. You can use the

moment.js

library or use Java objects. The

moment.js

library is a JavaScript date library for parsing, validating, manipulating, and formatting dates.

The following example uses the

moment.js

library:

var orderDate = currentBean.order_date.getTime();var shippingDate = currentBean.shipping_date.getTime();currentBean.processing_delay = moment(orderData).from(shippingData, true);

For more information about the

moment.js

library, see the moment.js site.

Use Library Facilities in your Rules

Prerequisite:
You have added a library to your API.

You can use a library's facilities in your rules by invoking methods inside classes directly from JavaScript.

Example:

The following

myClass

Java class contains the

add()

method:

public class MyClass {  public static int add(int a, int b) {    return a+b;  }}

You can invoke the

add()

method by adding the following code snippet to your JavaScript with the

Java.type

keyword:

var MyClassObject = Java.type("MyClass");var myResult = MyClassObject.add(1,2);

If your Java class is part of a package, for example

foo.bar.MyClass

, then provide the full name of the class while accessing the

Class

object.

For more information about using Java inside JavaScript, see JavaScript.

Logic

CA Live API Creator 3.1

Logic Libraries