View source for STEM Create EMF Project

= How to create a JSON Logger for STEM: Tutorial demonstrating a new EMF Project =

 # Notes
 * I substitute "`org.eclipse.stem`" with "`o.e.s`" in places

== Create an EMF Project ==
1.  File -> New -> Eclipse Modeling Framework -> Empty EMF Project
2.  Project Name:  `org.eclipse.stem.loggers.json`

(note:  another way to do this it to create the EMF model from a regular (non-EMF) project, then use the code generator to generate the EMF project.  This can be useful if you're experimenting and will need to delete 

== Create Ecore Model ==

# File > New > Other > EMF -> Ecore Model.  Click **Next**.
# Enter name `json.ecore`.  **Finish**.
# The **EMF Ecore Model Editor** should now open
# Load Resource references: 
## Right click, **Load Resources** > **Browse Workspace**
## Select `o.e.s.loggers/model/SimulationLogger.ecore`
# Set EPackage details.  Select the (empty) EPackage in the editor
## Name:  `json2`
## Ns Prefix: `org.eclipse.stem.loggers.json`
## NS URI: `http:///org/eclipse/stem/loggers/json`
# Create EClass
## Right click on `json` EPackage > New Child -> EClass
## Name:  `JsonLogger`
## ESuper Type:  `SynchronousDecoratorPropertyLogger`
# Add new `logPath` EAttribute to `JsonLogger`
## Right click on `JsonLogger`  > New Child -> EAttribute
## Name: `logPath`
## EType:  `EString`
#  Add new `prettyPrint` EAttribute to EClass
## Name:  prettyPrint
## EType:  EBoolean
## Default value literal:  false
#  Save `json.ecore`

== Create Generator Model (GenModel) ==
# Right click on the `json.ecore` file
# File > New > Other > EMF > EMF Generator Model.  **Next**
# File name:  `json.genmodel` in the `o.e.s.loggers.json/model` folder.  **Next**
# Model importer;  **Ecore Model**.  **Next**
# Select `json.ecore` and click **Load**.  **Next**
# Select the appropriate packages:
## Root packages (top):  `json`
## Referenced generator models (bottom):  Select the require ones (until errors go away)
## Click **Finish**

== Customize the Generator Model (Tricky) ==

* In the `Properties` view, make the changes to these sections
** All
** Edit
*** Remove '.edit' from the Edit plug-in ID and Directory
*** Set Edit Plug-in Class to have the fully qualified package name (org.eclipse.stem.loggers.json)
** Editor
*** Remove '.editor' from Editor plug-in ID and Directory
*** Set Editor Plug-in to have fully qualified package name (org.eclipse.stem.loggers.json)
** Model
*** No changes, although discuss suppressions (incl suppress notifications)
** Model Class Defaults
*** Public constructors to true
*** Set `Root Extends Class` to `org.eclipse.emf.ecore.impl.EObjectImpl` (the current default refers to new EMF behavior that is not understood or tested
** Model Feature Defaults
*** No Changes
** Templates & Merge
*** This is an interesting section and is used by parts of STEM to extend EMF (the Model Builder)
*** No changes required right now
** Next, Select the `json` EPackage
*** Set Base Package to be `org.eclipse.stem.loggers`
*** Set Model / File Extension to `logger`
** Save Genmodel

== Run the EMF Code Generator ==
* Right click on the GenModel (Top icon) 
* Select Generate Model > Generate All

== Correct Errors from Code Generation ==

* Remove unneeded lines from '''JsonPackage.java'''
** Open '''src/o.e.s.loggers.json/JsonPackage.java'''
** Comment out lines with errors
*** Lines 167, 176, 185, 194, 203
** Save '''JsonPackage.java'''

==  Fix error in JsonEditor ==
	
* Open `src/org.eclipse.stem.loggers.json.presentation/JsonEditor.java`
* Go to line 984, 
 change:
 '''EditUIUtil.getURI(getEditorInput(), editingDomain.getResourceSet().getURIConverter());'''
 to 
 '''EditUIUtil.getURI(getEditorInput());'''

== Add Extension Point definition == 

* Open org.eclipse.stem.loggers.json/plugin.xml

 Inside the '''<plugin>''' tag 
 Add:

 <extension point="org.eclipse.stem.core.logger">
  <classdef class="org.eclipse.stem.loggers.json.impl.JSONLoggerImpl">
  </classdef>
  <dublin_core
    category_id="/"
    creator="%dc_creator"
    description="%dc_descr"
    identifier="%dc_identifier"
    license="%dc_license"
    publisher="%dc_publisher"
    source="%dc_source"
    title="%dc_title"/>
 </extension>

* Next, open org.eclipse.stem.loggers.json/plugin.properties and add or update the properties to

 pluginName = STEM JSON Logger
 providerName = Eclipse Foundation
	
 dc_identifier=org.eclipse.stem.loggers.json.dublin_core
 dc_publisher = The Eclipse Foundation
 dc_license = Eclipse Public License (EPL)
 dc_title = JSON File Logger
 dc_descr = STEM logger for writing the results of a simulation to a JSON formatted file
 dc_creator = STEM team
 dc_source = http://wiki.eclipse.org/STEM_Loggers

== Add the new plug-in to STEM's '''Run Configuration''' == 

* Go to Run menu > Run Configurations
* Select '''stem2.product''', then select **'''Plug-ins'''** tab
* Scroll through **Plug-ins** and check '''org.eclipse.stem.loggers.json''' 
* Click **Apply** then **Close**

== Test Creating Logger in STEM == 
* Launch STEM
* Click the new Logger wizard, JSON File Logger should be in the list.  Select it
	* Notice how the names in the wizard aren't really filled out yet.  This is because we haven't hooked in the UI adapters yet.  You can create the logger without these UI hooks, but the display (and NLS-supported) names don't show up
			
			
== Implement the Logger == 

* Open `o.e.s.loggers.json.impl/JSONLoggerImpl.java`
* Add the following lines to override the parent methods called when a loggable event occurs

 @Override
 public void simulationEvent(SimulationEvent event) {
 
 }

 @Override
 public void loggerEvent(ISimulation simulation, LOGGER_EVENTS event) {
 
 }

* The '''loggerEvents(...)''' method receives notifications of logger events, including the creation of a new simulation that has a logger, the enabling or disabling of loggers, etc.
* The '''simulationEvent(...)''' method receives notifications of simulation events.  
* To see a stream of events being received by the logger in the console, add the following to '''simulationEvent'''

 System.err.println("JSON Logger Event: ["+event+"]");