The workflow explainedThis workflow engine takes a little different approach like other frameworks. At least other frameworks tha we know about.
Every process item inside a workflow can set variables and these variables can be used by other items in order to communicate.
Most other framework lets you define a return value of your action and then you define a forward depending on the return value. This is not really sufficient for a good inter process communication where different items needs to share common informations.
First exampleThese variables can be set by views or commands and can be used by all items. Setting a variable can be done like this:
import org.jzonic.core.AbstractCommand;
import org.jzonic.core.CommandException;
import org.jzonic.core.WebContext;
public class ExampleCommand extends AbstractCommand {
public ExampleCommand() {
}
public String execute(WebContext context) throws CommandException {
String val = context.getRequestParameter("value");
context.setVariable("varname", val);
return null;
}
}
This will add the variable called "varname" with the value from the request parameter "value".
Using this variable inside an if/else block is here:
<page name="redirect">
<command>ExampleCommand</command>
<if expression="${varname}='hello'">
<view>WelcomeView</view>
</if>
<else>
<redirect>index.jz</redirect>
</else>
</page>
Second example - Using a variable inside a process item definitionYou can also use this to "skin" your applications by using a different jsp depending on such a variable:
import org.jzonic.core.AbstractCommand;
import org.jzonic.core.CommandException;
import org.jzonic.core.WebContext;
public class SkinExampleCommand extends AbstractCommand {
public SkinExampleCommand() {
}
public String execute(WebContext context) throws CommandException {
// just get the info from an imaginary configuration
String val = config.getProperty("skin");
context.setVariable("theme", val);
return null;
}
}
and now put it in a page:
<page name="main">
<command>SkinExampleCommand</command>
<jsp>${theme}/hello.jsp</jsp>
</page>
When you use a variable inside a process item you have to put it in ${varname}. This example will take the JSP from the corresponding subdirectory of your webapps directory.
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