[FIXED JENKINS-35698] Make params offer default parameter values from…

… the current definition as a fallback.
jenkinsci · Oct 10, 2016 · 0161aec · 0161aec
1 parent f752ab1
commit 0161aec
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Showing 2 changed files with 53 additions and 24 deletions.
diff --git a/src/main/java/org/jenkinsci/plugins/workflow/cps/ParamsVariable.java b/src/main/java/org/jenkinsci/plugins/workflow/cps/ParamsVariable.java
@@ -25,8 +25,10 @@
 package org.jenkinsci.plugins.workflow.cps;
 
 import hudson.Extension;
+import hudson.model.ParameterDefinition;
 import hudson.model.ParameterValue;
 import hudson.model.ParametersAction;
+import hudson.model.ParametersDefinitionProperty;
 import hudson.model.Run;
 import java.io.Serializable;
 import java.util.Collections;
@@ -50,37 +52,51 @@
         if (b == null) {
             throw new IllegalStateException("cannot find owning build");
         }
-        ParametersAction action = b.getAction(ParametersAction.class);
-        if (action == null) {
-            return Collections.emptyMap();
-        }
-        List<ParameterValue> parameterValues;
-        try { // TODO 1.651.2+ remove reflection
-            parameterValues = (List<ParameterValue>) ParametersAction.class.getMethod("getAllParameters").invoke(action);
-        } catch (NoSuchMethodException x) {
-            parameterValues = action.getParameters();
-        }
         // Could extend AbstractMap and make a Serializable lazy wrapper, but getValue impls seem cheap anyway.
         Map<String,Object> values = new HashMap<>();
-        for (ParameterValue parameterValue : parameterValues) {
-            Object value = parameterValue.getValue();
-            if (!(value instanceof Serializable)) {
-                boolean canPickle = false;
-                for (PickleFactory pf : PickleFactory.all()) {
-                    if (pf.writeReplace(value) != null) {
-                        // For example SecretPickle can handle Secret from PasswordParameterValue.
-                        canPickle = true;
-                        break;
+        ParametersAction action = b.getAction(ParametersAction.class);
+        if (action != null) {
+            List<ParameterValue> parameterValues;
+            try { // TODO 1.651.2+ remove reflection
+                parameterValues = (List<ParameterValue>) ParametersAction.class.getMethod("getAllParameters").invoke(action);
+            } catch (NoSuchMethodException x) {
+                parameterValues = action.getParameters();
+            }
+            for (ParameterValue parameterValue : parameterValues) {
+                addValue(values, parameterValue);
+            }
+        }
+        ParametersDefinitionProperty prop = b.getParent().getProperty(ParametersDefinitionProperty.class);
+        if (prop != null) { // JENKINS-35698: look for default values as well
+            for (ParameterDefinition param : prop.getParameterDefinitions()) {
+                if (!values.containsKey(param.getName())) {
+                    ParameterValue defaultParameterValue = param.getDefaultParameterValue();
+                    if (defaultParameterValue != null) {
+                        addValue(values, defaultParameterValue);
                     }
                 }
-                if (!canPickle) {
-                    // Just skip anything not serializable, such as a Run from a RunParameterValue.
-                    continue;
-                }
             }
-            values.put(parameterValue.getName(), value);
         }
         return Collections.unmodifiableMap(values);
     }
 
+    private static void addValue(Map<String, Object> values, ParameterValue parameterValue) {
+        Object value = parameterValue.getValue();
+        if (!(value instanceof Serializable)) {
+            boolean canPickle = false;
+            for (PickleFactory pf : PickleFactory.all()) {
+                if (pf.writeReplace(value) != null) {
+                    // For example SecretPickle can handle Secret from PasswordParameterValue.
+                    canPickle = true;
+                    break;
+                }
+            }
+            if (!canPickle) {
+                // Just skip anything not serializable, such as a Run from a RunParameterValue.
+                return;
+            }
+        }
+        values.put(parameterValue.getName(), value);
+    }
+
 }
diff --git a/src/main/resources/org/jenkinsci/plugins/workflow/cps/ParamsVariable/help.jelly b/src/main/resources/org/jenkinsci/plugins/workflow/cps/ParamsVariable/help.jelly
@@ -29,4 +29,17 @@ THE SOFTWARE.
         Exposes all parameters defined in the build as a read-only map with variously typed values. Example:
     </p>
     <pre><code>if (params.BOOLEAN_PARAM_NAME) {doSomething()}</code></pre>
+    <p>
+        Note for multibranch (<code>Jenkinsfile</code>) usage: the <code>properties</code> step allows you to define job properties,
+        but these take effect when the step is run, whereas build parameter definitions are generally consulted before the build begins.
+        As a convenience, any parameters <em>currently</em> defined in the job which have default values will also be listed in this map.
+        That allows you to write, for example:
+    </p>
+    <pre><code>properties([parameters([string(name: 'BRANCH', defaultValue: 'master')])])
+git url: '…', branch: params.BRANCH
+</code></pre>
+    <p>
+        and be assured that the <code>master</code> branch will be checked out even in the initial build of a branch project,
+        or if the previous build did not specify parameters or used a different parameter name.
+    </p>
 </j:jelly>