New features in Assemble Silverstone M2

General Connection API Features

• Make it easier to set override parameters on Connection (6135)
  • setProtocolConfiguration(null, configMap)
    • Configuration will be supplied to whichever protocol is selected.
    • Previously had to name the protocol so the application had to pre-empt protocol selection in order to supply programmatic configuration.

• POSTJMSMessage activity in zero.connection.jms (6366)
  • Allows flows to send a message to a configured external JMS provider.
  • Based on existing POSTMessage from the Reliable Transport Extension.

• MQ Connectivity from Connection API (5962)
  • Documentation for zero.connection.jms now contains notes for WebSphere MQ (in addition to WebSphere Application Server).
  • Test and doc changes only – no functional change since 1.0.x

• Added new zero.connection.demo to samples (3381)

Connection “sftp” protocol (2694)

• sftp protocol for Connection API
  • zero.connection.sftp
  • Includes OSSC Jsch SSH implementation

• Similar to file and ftp protocols in zero.core

• Supported operations:
  • GET – read remote file contents
  • PUT – write/replace remote file contents
  • DELETE – delete remote file

• Automatically selected for resource using sftp: prefix
  • Connection.doGET(“sftp://localhost:22/hello_world.txt”).getResponseBodyAsString()

Connection “sftp” protocol (2694)

• SSH server can be verified in two ways:
  • Standard SSH known hosts file, e.g.:
    • /config/connection/defaults/sftp/knownHosts = "/home/mnuttall/.ssh/known_hosts"
  • Fingerprint in connection destination configuration, e.g.:

  /config/connection/destinations += {  
    "sftp://myhost.mydomain.com:22/*" : {    
      "connection": {      
        "protocol" : "sftp",      
          "config": {       
            "fingerprint" :         
               "ab:2e:0b:fc:75:91:aa:be:cc:dd:01:0f:ff:4d:1f:71“     
             }
        }
    }
  } 

POP3 mail kicker and receiver (5448)

• Allows request processing to be trigged by an e-mail message.
• Example uses:
  • “Subscribe”/”Unsubscribe” auto-responder.
  • Accept XML documents sent by e-mail from third-party applications.
• Features:
  • Monitors POP3 folder using kicker/receiver pattern.
  • Separates message body, attachments and inline content into separate streams.
  • Note this loses the internal structure of a multi-part message.
  • Includes activities to handle incoming e-mail in a flow.
• Limitations:
  • No official support for POP3 over SSL (being added in M3)
  • No official support for IMAP (possible future enhancement)
  • No Connection API protocol to examine contents of POP3 folder
• Components:
  • zero.mail.kicker

Polls POP3 folder for new e-mail messages “Kicks” receiver when one arrives

• • zero.mail.receiver
    • Reads new message into GlobalContext
    • Fires mailMessage event
    • Deletes e-mail from queue when request complete
    • Also includes activities for use with zero.assemble.flow
  • zero.mail (not explicit in documentation)
    • Parent dependency containing common code for kicker and receiver.
• GlobalContext for mailMessage event:
  • /request/mail/headers/ headerName
    • Values of the named header of the message, represented as a FirstElementList.
  • /request/mail/body/headers/ headerName
    • Values of the named header of the first message body, represented as a FirstElementList.
  • /request/mail/body/contentType
    • Content type value of the first message body.
  • /request/mail/body/inputStream
    • Input stream containing the first message body.
  • /request/mail/allBodies
    • List containing all message bodies.
  • /request/mail/attachments
    • List containing all attachments and inline content.

• Example flow to handle email and attachment:

  <process name="myMailMessageFlow&#8220; 
             expressionLanguage="Groovy">  
    <receiveMailMessage name="receiveMailMessage_0"/>  
    <findMailAttachment name="findMailAttachment_0&#8220;
                file-name=&#8220;account(.*)?&#8220;
                content-type=&#8220;text/xml&#8221;>
      <control   source="$receiveMailMessage_0"/>
    </findMailAttachment>
    <getMailAttachmentContent
                name="getMailAttachmentContent_0">
      <input value="${findMailAttachment_0}"/>
    </getMailAttachmentContent>
  </process> 

Flow and Tooling

Summary of New Features

• Support the AJAX API for JavaScript developer to simplify the feed processing in browser-side by leveraging Assemble flow’s capability
• Support the flow persistence
• New user experience of Flow Editor

AJAX Feed API – zero.feed

• Simplify the feed accessing and manipulation in browser-side for JavaScript developer by leveraging server-side Assemble flow capabilities.
• JavaScript API in the browser
  • Fluent API with method chaining
  • Support the synchronized or asynchronized calling.
  • Resulting feed in both XML and JSON format
• Assemble flow in the backend
  • Cross-domain access
  • High performance feed operations by stream processing
    • E.g. aggregate, filter, exclude, after, before, unique, top, etc.
  • Feed format support: RSS 0.9x/1.0/2.0, ATOM 0.3/1.0

Code Sample:

Demo: Feeds of WebSphere sMash

1 Aggregate feed from projectzero.org (blog and forum), and Google BlogSearch 2 Remove duplicate entry 3 Sort by published date 4 Get top 20 entries.

Flow Persistence

• In previous release, the Assemble flow engine leverage the APP zone of GlobalContext to management the visibility and lifecycle of flow context information.
  • The flow context could be survived after JVM recycle, but it could not be survived after zero application stopping.
• In this release, we provides a simple and extensible persistence mechanism to store the flow instances.
  • Configurable FlowContextManager. There are two implementations included with flow engine.
    • DefaultFlowContextManager: store the flow context into "app" zone of GlobalContext
    • JDBCFlowContextManager: store in Database based on zero.data
  • The “flowStateChange” event will trigger the event handler to store the flow instance.

Persistence Policy

• Different flows may have the different requirements of persistence. E.g. the flow execution for feed aggregation is transient, the flow status is not required for persistence.
• The developer can specify the persistence policy by setting the "persistPolicy" attribute in "process" element of flow definition. Currently, Assemble flow engine support the following persistence policies
  • “on” : Default value. All flow instances are saved normally.
  • “failed”: Only failed instances will be saved. The instances complete successfully will not be saved
  • “off”: No instances will be stored.

New User Experience of Flow Editor

New User Experience of Flow Editor (Cont.)