Examples of org.activiti.engine.impl.javax.el.ELContext

org.activiti.engine.impl.javax.el.ELContext

Context information for expression evaluation. To evaluate an {@link Expression}, an ELContext must be provided. The ELContext holds:

a reference to the base {@link ELResolver} that will be consulted to resolve model objectsand their properties
a reference to {@link FunctionMapper} that will be used to resolve EL Functions.
a reference to {@link VariableMapper} that will be used to resolve EL Variables.
a collection of all the relevant context objects for use by ELResolvers
state information during the evaluation of an expression, such as whether a property has been resolved yet

The collection of context objects is necessary because each ELResolver may need access to a different context object. For example, JSP and Faces resolvers need access to a javax.servlet.jsp.JspContext and a javax.faces.context.FacesContext, respectively. Creation of ELContext objects is controlled through the underlying technology. For example, in JSP the JspContext.getELContext() factory method is used. Some technologies provide the ability to add an {@link ELContextListener} so that applications and frameworks can ensure their own contextobjects are attached to any newly created ELContext. Because it stores state during expression evaluation, an ELContext object is not thread-safe. Care should be taken to never share an ELContext instance between two or more threads.

    SecurityManager securityManager = System.getSecurityManager();
    if (securityManager == null) {
      scriptCtx.setAttribute("lang:import", getImportMethod(), ScriptContext.ENGINE_SCOPE);
    }


    ELContext elContext = new ELContext() {


      ELResolver resolver = createElResolver();
      VariableMapper varMapper = new ScriptContextVariableMapper(scriptCtx);
      FunctionMapper funcMapper = new ScriptContextFunctionMapper(scriptCtx);

  public void setExpressionFactory(ExpressionFactory expressionFactory) {
    this.expressionFactory = expressionFactory;
  }


  public ELContext getElContext(VariableScope variableScope) {
    ELContext elContext = null;
    if (variableScope instanceof VariableScopeImpl) {
      VariableScopeImpl variableScopeImpl = (VariableScopeImpl) variableScope;
      elContext = variableScopeImpl.getCachedElContext();
    }

Examples of org.activiti.engine.impl.javax.el.ELContext

Related Classes of org.activiti.engine.impl.javax.el.ELContext