--- /dev/null
+/*
+ * Copyright (C) 2007-2012 Argeo GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.argeo.slc.execution;
+
+/**
+ * Possible attribute of an execution flow.
+ *
+ * There are mainly two implementations :<br>
+ * + Primitive attributes (no predefined choice, the end user must compute a
+ * String, a Float, an Integer...)<br>
+ * + RefSpecAttribute which enable two things<br>
+ * ++ a reference to another object of the application context<br>
+ * ++ the display of some choices among which the end user can choose.<br>
+ *
+ * @see org.argeo.slc.core.execution.PrimitiveSpecAttribute
+ * @see org.argeo.slc.core.execution.RefSpecAttribute
+ * @see org.argeo.slc.core.execution.PrimitiveUtils : this class offers some
+ * helper, among others to cast the various type of primitive attribute.
+ */
+public interface ExecutionSpecAttribute {
+ /**
+ * Whether this attribute has to be set at instantiation of the flow and
+ * cannot be modified afterwards. If the attribute is not immutable (that
+ * is, this method returns false), it can be set at execution time.
+ */
+ public Boolean getIsImmutable();
+
+ /**
+ * Whether this attribute must be explicitly set and cannot be modified.
+ * This attribute is then basically a constant within a given application
+ * context. {@link #getValue()} cannot return null if the attribute is a
+ * constant.
+ */
+ public Boolean getIsConstant();
+
+ /** Whether this attribute will be hidden to end users. */
+ public Boolean getIsHidden();
+
+ /**
+ * The default value for this attribute. Can be null, except if
+ * {@link #getIsFrozen()} is <code>true</code>, in which case it represents
+ * the constant value of this attribute.
+ */
+ public Object getValue();
+
+ /** Description of this attribute, can be null */
+ public String getDescription();
+
+ /** @deprecated use {@link #getIsImmutable()} instead */
+ public Boolean getIsParameter();
+
+ /** @deprecated use {@link #getIsConstant()} instead */
+ public Boolean getIsFrozen();
+
+}