runtime/org.argeo.slc.specs/src/main/java/org/argeo/slc/execution/ExecutionSpecAttribute.java

   1 /*
   2  * Copyright (C) 2010 Mathieu Baudier <mbaudier@argeo.org>
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 package org.argeo.slc.execution;
  18
  19 /**
  20  * Possible attribute of an execution flow.
  21  *
  22  * There are mainly two implementations :<br>
  23  * + Primitive attributes (no predefined choice, the end user must compute a
  24  * String, a Float, an Integer...)<br>
  25  * + RefSpecAttribute which enable two things<br>
  26  * ++ a reference to another object of the application context<br>
  27  * ++ the display of some choices among which the end user can choose.<br>
  28  *
  29  * @see org.argeo.slc.core.execution.PrimitiveSpecAttribute
  30  * @see org.argeo.slc.core.execution.RefSpecAttribute
  31  * @see org.argeo.slc.core.execution.PrimitiveUtils : this class offers some
  32  *      helper, among others to cast the various type of primitive attribute.
  33  */
  34 public interface ExecutionSpecAttribute {
  35         /**
  36          * Whether this attribute has to be set at instantiation of the flow and
  37          * cannot be modified afterwards. If the attribute is not immutable (that
  38          * is, this method returns false), it can be set at execution time.
  39          */
  40         public Boolean getIsImmutable();
  41
  42         /**
  43          * Whether this attribute must be explicitly set and cannot be modified.
  44          * This attribute is then basically a constant within a given application
  45          * context. {@link #getValue()} cannot return null if the attribute is a
  46          * constant.
  47          */
  48         public Boolean getIsConstant();
  49
  50         /** Whether this attribute will be hidden to end users. */
  51         public Boolean getIsHidden();
  52
  53         /**
  54          * The default value for this attribute. Can be null, except if
  55          * {@link #getIsFrozen()} is <code>true</code>, in which case it represents
  56          * the constant value of this attribute.
  57          */
  58         public Object getValue();
  59
  60         /** @deprecated use {@link #getIsImmutable()} instead */
  61         public Boolean getIsParameter();
  62
  63         /** @deprecated use {@link #getIsConstant()} instead */
  64         public Boolean getIsFrozen();
  65
  66 }