com.google.javascript.jscomp.PolymerClassRewriter Maven / Gradle / Ivy
/*
* Copyright 2016 The Closure Compiler Authors.
*
* 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 com.google.javascript.jscomp;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Splitter;
import com.google.common.collect.ImmutableList;
import com.google.javascript.jscomp.PolymerBehaviorExtractor.BehaviorDefinition;
import com.google.javascript.jscomp.PolymerPass.MemberDefinition;
import com.google.javascript.jscomp.parsing.parser.FeatureSet;
import com.google.javascript.rhino.IR;
import com.google.javascript.rhino.JSDocInfo;
import com.google.javascript.rhino.JSDocInfo.Visibility;
import com.google.javascript.rhino.JSDocInfoBuilder;
import com.google.javascript.rhino.JSTypeExpression;
import com.google.javascript.rhino.Node;
import com.google.javascript.rhino.Token;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
/**
* Rewrites a given call to Polymer({}) to a set of declarations and assignments which can be
* understood by the compiler.
*/
final class PolymerClassRewriter {
private static final String VIRTUAL_FILE = "";
private final AbstractCompiler compiler;
private final int polymerVersion;
private final PolymerExportPolicy polymerExportPolicy;
private final boolean propertyRenamingEnabled;
@VisibleForTesting static final String POLYMER_ELEMENT_PROP_CONFIG = "PolymerElementProperties";
private final Node polymerElementExterns;
boolean propertySinkExternInjected = false;
PolymerClassRewriter(
AbstractCompiler compiler,
Node polymerElementExterns,
int polymerVersion,
PolymerExportPolicy polymerExportPolicy,
boolean propertyRenamingEnabled) {
this.compiler = compiler;
this.polymerElementExterns = polymerElementExterns;
this.polymerVersion = polymerVersion;
this.polymerExportPolicy = polymerExportPolicy;
this.propertyRenamingEnabled = propertyRenamingEnabled;
}
/**
* Rewrites a given call to Polymer({}) to a set of declarations and assignments which can be
* understood by the compiler.
*
* @param exprRoot The root expression of the call to Polymer({}).
* @param cls The extracted {@link PolymerClassDefinition} for the Polymer element created by this
* call.
*/
void rewritePolymerCall(
Node exprRoot, final PolymerClassDefinition cls, boolean isInGlobalScope) {
Node objLit = checkNotNull(cls.descriptor);
// Add {@code @lends} to the object literal.
JSDocInfoBuilder objLitDoc = new JSDocInfoBuilder(true);
JSTypeExpression jsTypeExpression =
new JSTypeExpression(
IR.string(cls.target.getQualifiedName() + ".prototype"), exprRoot.getSourceFileName());
objLitDoc.recordLends(jsTypeExpression);
objLit.setJSDocInfo(objLitDoc.build());
addTypesToFunctions(objLit, cls.target.getQualifiedName(), cls.defType);
PolymerPassStaticUtils.switchDollarSignPropsToBrackets(objLit, compiler);
PolymerPassStaticUtils.quoteListenerAndHostAttributeKeys(objLit, compiler);
for (MemberDefinition prop : cls.props) {
if (prop.value.isObjectLit()) {
PolymerPassStaticUtils.switchDollarSignPropsToBrackets(prop.value, compiler);
}
}
// For simplicity add everything into a block, before adding it to the AST.
Node block = IR.block();
JSDocInfoBuilder constructorDoc = this.getConstructorDoc(cls);
// Remove the original constructor JS docs from the objlit.
Node ctorKey = cls.constructor.value.getParent();
if (ctorKey != null) {
ctorKey.removeProp(Node.JSDOC_INFO_PROP);
}
if (cls.target.isGetProp()) {
// foo.bar = Polymer({...});
Node assign = IR.assign(cls.target.cloneTree(), cls.constructor.value.cloneTree());
NodeUtil.markNewScopesChanged(assign, compiler);
assign.setJSDocInfo(constructorDoc.build());
Node exprResult = IR.exprResult(assign);
exprResult.useSourceInfoIfMissingFromForTree(cls.target);
block.addChildToBack(exprResult);
} else {
// var foo = Polymer({...}); OR Polymer({...});
Node var = IR.var(cls.target.cloneTree(), cls.constructor.value.cloneTree());
NodeUtil.markNewScopesChanged(var, compiler);
var.useSourceInfoIfMissingFromForTree(exprRoot);
var.setJSDocInfo(constructorDoc.build());
block.addChildToBack(var);
}
appendPropertiesToBlock(cls.props, block, cls.target.getQualifiedName() + ".prototype.");
appendBehaviorMembersToBlock(cls, block);
ImmutableList readOnlyProps = parseReadOnlyProperties(cls, block);
ImmutableList attributeReflectedProps =
parseAttributeReflectedProperties(cls);
createExportsAndExterns(cls, readOnlyProps, attributeReflectedProps);
removePropertyDocs(objLit, PolymerClassDefinition.DefinitionType.ObjectLiteral);
Node statements = block.removeChildren();
Node parent = exprRoot.getParent();
// If the call to Polymer() is not in the global scope and the assignment target
// is not namespaced (which likely means it's exported to the global scope), put the type
// declaration into the global scope at the start of the current script.
//
// This avoids unknown type warnings which are a result of the compiler's poor understanding of
// types declared inside IIFEs or any non-global scope. We should revisit this decision as
// the typechecker's support for non-global types improves.
if (!isInGlobalScope && !cls.target.isGetProp()) {
Node scriptNode = NodeUtil.getEnclosingScript(parent);
scriptNode.addChildrenToFront(statements);
compiler.reportChangeToChangeScope(scriptNode);
} else {
Node beforeRoot = exprRoot.getPrevious();
if (beforeRoot == null) {
parent.addChildrenToFront(statements);
} else {
parent.addChildrenAfter(statements, beforeRoot);
}
compiler.reportChangeToEnclosingScope(parent);
}
compiler.reportChangeToEnclosingScope(statements);
// Since behavior files might contain language features that aren't present in the class file,
// we might need to update the FeatureSet.
if (cls.features != null) {
Node scriptNode = NodeUtil.getEnclosingScript(parent);
FeatureSet oldFeatures = (FeatureSet) scriptNode.getProp(Node.FEATURE_SET);
FeatureSet newFeatures = oldFeatures.union(cls.features);
if (!newFeatures.equals(oldFeatures)) {
scriptNode.putProp(Node.FEATURE_SET, newFeatures);
compiler.reportChangeToChangeScope(scriptNode);
}
}
if (NodeUtil.isNameDeclaration(exprRoot)) {
Node assignExpr = varToAssign(exprRoot);
parent.replaceChild(exprRoot, assignExpr);
compiler.reportChangeToEnclosingScope(assignExpr);
}
// If property renaming is enabled, wrap the properties object literal
// in a reflection call so that the properties are renamed consistently
// with the class members.
if (polymerVersion > 1 && propertyRenamingEnabled && cls.descriptor != null) {
Node props = NodeUtil.getFirstPropMatchingKey(cls.descriptor, "properties");
if (props != null && props.isObjectLit()) {
addPropertiesConfigObjectReflection(cls, props);
}
}
}
/**
* Rewrites a class which extends Polymer.Element to a set of declarations and assignments which
* can be understood by the compiler.
*
* @param clazz The class node
* @param cls The extracted {@link PolymerClassDefinition} for the Polymer element created by this
* call.
*/
void rewritePolymerClassDeclaration(
Node clazz, NodeTraversal traversal, final PolymerClassDefinition cls) {
if (cls.descriptor != null) {
addTypesToFunctions(cls.descriptor, cls.target.getQualifiedName(), cls.defType);
}
PolymerPassStaticUtils.switchDollarSignPropsToBrackets(
NodeUtil.getClassMembers(clazz), compiler);
for (MemberDefinition prop : cls.props) {
if (prop.value.isObjectLit()) {
PolymerPassStaticUtils.switchDollarSignPropsToBrackets(prop.value, compiler);
}
}
// For simplicity add everything into a block, before adding it to the AST.
Node block = IR.block();
// For each Polymer property we found in the "properties" configuration object, append a
// property declaration to the prototype (e.g. "/** @type {string} */ MyElement.prototype.foo").
appendPropertiesToBlock(cls.props, block, cls.target.getQualifiedName() + ".prototype.");
ImmutableList readOnlyProps = parseReadOnlyProperties(cls, block);
ImmutableList attributeReflectedProps =
parseAttributeReflectedProperties(cls);
createExportsAndExterns(cls, readOnlyProps, attributeReflectedProps);
// If an external interface is required, mark the class as implementing it
if (polymerExportPolicy == PolymerExportPolicy.EXPORT_ALL
|| !readOnlyProps.isEmpty()
|| !attributeReflectedProps.isEmpty()) {
Node jsDocInfoNode = NodeUtil.getBestJSDocInfoNode(clazz);
JSDocInfoBuilder classInfo = JSDocInfoBuilder.maybeCopyFrom(jsDocInfoNode.getJSDocInfo());
String interfaceName = getInterfaceName(cls);
JSTypeExpression interfaceType =
new JSTypeExpression(new Node(Token.BANG, IR.string(interfaceName)), VIRTUAL_FILE);
classInfo.recordImplementedInterface(interfaceType);
jsDocInfoNode.setJSDocInfo(classInfo.build());
}
Node insertAfterReference = NodeUtil.getEnclosingStatement(clazz);
if (block.hasChildren()) {
removePropertyDocs(cls.descriptor, cls.defType);
Node newInsertAfterReference = block.getLastChild();
insertAfterReference
.getParent()
.addChildrenAfter(block.removeChildren(), insertAfterReference);
compiler.reportChangeToEnclosingScope(insertAfterReference);
insertAfterReference = newInsertAfterReference;
}
addReturnTypeIfMissing(cls, "is", new JSTypeExpression(IR.string("string"), VIRTUAL_FILE));
Node type = new Node(Token.BANG);
Node array = IR.string("Array");
type.addChildToBack(array);
Node arrayTemplateType = new Node(Token.BLOCK, IR.string("string"));
array.addChildToBack(arrayTemplateType);
addReturnTypeIfMissing(cls, "observers", new JSTypeExpression(type, VIRTUAL_FILE));
addReturnTypeIfMissing(
cls,
"properties",
new JSTypeExpression(IR.string(POLYMER_ELEMENT_PROP_CONFIG), VIRTUAL_FILE));
// If property renaming is enabled, wrap the properties object literal
// in a reflection call so that the properties are renamed consistently
// with the class members.
//
// Also add reflection and sinks for computed properties and complex observers
// and switch simple observers to direct function references.
if (propertyRenamingEnabled && cls.descriptor != null) {
convertSimpleObserverStringsToReferences(cls);
List propertySinks = new ArrayList<>();
if (polymerExportPolicy != PolymerExportPolicy.EXPORT_ALL) {
propertySinks.addAll(addComputedPropertiesReflectionCalls(cls));
propertySinks.addAll(addComplexObserverReflectionCalls(cls));
}
if (propertySinks.size() > 0) {
if (!propertySinkExternInjected
&& traversal.getScope().getVar(CheckSideEffects.PROTECTOR_FN) == null) {
CheckSideEffects.addExtern(compiler);
propertySinkExternInjected = true;
}
for (Node propertyRef : propertySinks) {
Node name = IR.name(CheckSideEffects.PROTECTOR_FN).srcref(propertyRef);
name.putBooleanProp(Node.IS_CONSTANT_NAME, true);
Node protectorCall = IR.call(name, propertyRef).srcref(propertyRef);
protectorCall.putBooleanProp(Node.FREE_CALL, true);
protectorCall = IR.exprResult(protectorCall).useSourceInfoFrom(propertyRef);
insertAfterReference.getParent().addChildAfter(protectorCall, insertAfterReference);
insertAfterReference = protectorCall;
}
compiler.reportChangeToEnclosingScope(insertAfterReference);
}
addPropertiesConfigObjectReflection(cls, cls.descriptor);
}
}
/** Adds return type information to class getters */
private void addReturnTypeIfMissing(
PolymerClassDefinition cls, String getterPropName, JSTypeExpression jsType) {
Node classMembers = NodeUtil.getClassMembers(cls.definition);
Node getter = NodeUtil.getFirstGetterMatchingKey(classMembers, getterPropName);
if (getter != null) {
JSDocInfo info = NodeUtil.getBestJSDocInfo(getter);
if (info == null || !info.hasReturnType()) {
JSDocInfoBuilder builder = JSDocInfoBuilder.maybeCopyFrom(info);
builder.recordReturnType(jsType);
getter.setJSDocInfo(builder.build());
}
}
}
/** Wrap the properties config object in an objectReflect call */
private void addPropertiesConfigObjectReflection(
PolymerClassDefinition cls, Node propertiesLiteral) {
checkNotNull(propertiesLiteral);
checkState(propertiesLiteral.isObjectLit());
Node parent = propertiesLiteral.getParent();
Node objReflectCall =
IR.call(
NodeUtil.newQName(compiler, "$jscomp.reflectObject"),
cls.target.cloneTree(),
propertiesLiteral.detach())
.useSourceInfoIfMissingFromForTree(propertiesLiteral);
parent.addChildToFront(objReflectCall);
compiler.reportChangeToEnclosingScope(parent);
}
/** Adds an @this annotation to all functions in the objLit. */
private void addTypesToFunctions(
Node objLit, String thisType, PolymerClassDefinition.DefinitionType defType) {
checkState(objLit.isObjectLit());
for (Node keyNode : objLit.children()) {
Node value = keyNode.getLastChild();
if (value != null && value.isFunction()) {
JSDocInfoBuilder fnDoc = JSDocInfoBuilder.maybeCopyFrom(keyNode.getJSDocInfo());
fnDoc.recordThisType(
new JSTypeExpression(new Node(Token.BANG, IR.string(thisType)), VIRTUAL_FILE));
keyNode.setJSDocInfo(fnDoc.build());
}
}
// Add @this and @return to default property values.
for (MemberDefinition property :
PolymerPassStaticUtils.extractProperties(
objLit,
defType,
compiler,
/** constructor= */
null)) {
if (!property.value.isObjectLit()) {
continue;
}
Node defaultValue = NodeUtil.getFirstPropMatchingKey(property.value, "value");
if (defaultValue == null || !defaultValue.isFunction()) {
continue;
}
Node defaultValueKey = defaultValue.getParent();
JSDocInfoBuilder fnDoc = JSDocInfoBuilder.maybeCopyFrom(defaultValueKey.getJSDocInfo());
fnDoc.recordThisType(
new JSTypeExpression(new Node(Token.BANG, IR.string(thisType)), VIRTUAL_FILE));
fnDoc.recordReturnType(PolymerPassStaticUtils.getTypeFromProperty(property, compiler));
defaultValueKey.setJSDocInfo(fnDoc.build());
}
}
/**
* Generates the _set* setters for readonly properties and appends them to the given block.
*
* @return A List of all readonly properties.
*/
private ImmutableList parseReadOnlyProperties(
final PolymerClassDefinition cls, Node block) {
String qualifiedPath = cls.target.getQualifiedName() + ".prototype.";
ImmutableList.Builder readOnlyProps = ImmutableList.builder();
for (MemberDefinition prop : cls.props) {
// Generate the setter for readOnly properties.
if (prop.value.isObjectLit()) {
Node readOnlyValue = NodeUtil.getFirstPropMatchingKey(prop.value, "readOnly");
if (readOnlyValue != null && readOnlyValue.isTrue()) {
Node setter = makeReadOnlySetter(prop.name.getString(), qualifiedPath);
setter.useSourceInfoIfMissingFromForTree(prop.name);
block.addChildToBack(setter);
readOnlyProps.add(prop);
}
}
}
return readOnlyProps.build();
}
/**
* Generates the _set* setters for readonly properties and appends them to the given block.
*
* @return A List of all readonly properties.
*/
private ImmutableList parseAttributeReflectedProperties(
final PolymerClassDefinition cls) {
ImmutableList.Builder attrReflectedProps = ImmutableList.builder();
for (MemberDefinition prop : cls.props) {
// Generate the setter for readOnly properties.
if (prop.value.isObjectLit()) {
Node reflectedValue = NodeUtil.getFirstPropMatchingKey(prop.value, "reflectToAttribute");
if (reflectedValue != null && reflectedValue.isTrue()) {
attrReflectedProps.add(prop);
}
}
}
return attrReflectedProps.build();
}
/** @return The proper constructor doc for the Polymer call. */
private JSDocInfoBuilder getConstructorDoc(final PolymerClassDefinition cls) {
JSDocInfoBuilder constructorDoc = JSDocInfoBuilder.maybeCopyFrom(cls.constructor.info);
constructorDoc.recordConstructor();
JSTypeExpression baseType =
new JSTypeExpression(
new Node(Token.BANG, IR.string(PolymerPassStaticUtils.getPolymerElementType(cls))),
VIRTUAL_FILE);
constructorDoc.recordBaseType(baseType);
String interfaceName = getInterfaceName(cls);
JSTypeExpression interfaceType =
new JSTypeExpression(new Node(Token.BANG, IR.string(interfaceName)), VIRTUAL_FILE);
constructorDoc.recordImplementedInterface(interfaceType);
return constructorDoc;
}
/** Appends all of the given properties to the given block. */
private void appendPropertiesToBlock(List props, Node block, String basePath) {
for (MemberDefinition prop : props) {
Node propertyNode =
IR.exprResult(NodeUtil.newQName(compiler, basePath + prop.name.getString()));
// If a property string is quoted, make sure the added prototype properties are also quoted
if (prop.name.isQuotedString()) {
continue;
}
propertyNode.useSourceInfoIfMissingFromForTree(prop.name);
JSDocInfoBuilder info = JSDocInfoBuilder.maybeCopyFrom(prop.info);
JSTypeExpression propType = PolymerPassStaticUtils.getTypeFromProperty(prop, compiler);
if (propType == null) {
return;
}
info.recordType(propType);
propertyNode.getFirstChild().setJSDocInfo(info.build());
block.addChildToBack(propertyNode);
}
}
/** Remove all JSDocs from properties of a class definition */
private void removePropertyDocs(
final Node objLit, PolymerClassDefinition.DefinitionType defType) {
for (MemberDefinition prop :
PolymerPassStaticUtils.extractProperties(
objLit,
defType,
compiler,
/** constructor= */
null)) {
prop.name.removeProp(Node.JSDOC_INFO_PROP);
}
}
/** Appends all required behavior functions and non-property members to the given block. */
private void appendBehaviorMembersToBlock(final PolymerClassDefinition cls, Node block) {
String qualifiedPath = cls.target.getQualifiedName() + ".prototype.";
Map nameToExprResult = new HashMap<>();
for (BehaviorDefinition behavior : cls.behaviors) {
for (MemberDefinition behaviorFunction : behavior.functionsToCopy) {
String fnName = behaviorFunction.name.getString();
// Don't copy functions already defined by the element itself.
if (NodeUtil.getFirstPropMatchingKey(cls.descriptor, fnName) != null) {
continue;
}
// Avoid copying over the same function twice. The last definition always wins.
if (nameToExprResult.containsKey(fnName)) {
block.removeChild(nameToExprResult.get(fnName));
}
Node fnValue = behaviorFunction.value.cloneTree();
NodeUtil.markNewScopesChanged(fnValue, compiler);
Node exprResult =
IR.exprResult(IR.assign(NodeUtil.newQName(compiler, qualifiedPath + fnName), fnValue));
exprResult.useSourceInfoIfMissingFromForTree(behaviorFunction.name);
JSDocInfoBuilder info = JSDocInfoBuilder.maybeCopyFrom(behaviorFunction.info);
// Uses of private members that come from behaviors are not recognized correctly,
// so just suppress that warning.
info.addSuppression("unusedPrivateMembers");
// If the function in the behavior is @protected, switch it to @public so that
// we don't get a visibility warning. This is a bit of a hack but easier than
// making the type system understand that methods are "inherited" from behaviors.
if (behaviorFunction.info != null
&& behaviorFunction.info.getVisibility() == Visibility.PROTECTED) {
info.overwriteVisibility(Visibility.PUBLIC);
}
// Behaviors whose declarations are not in the global scope may contain references to
// symbols which do not exist in the element's scope. Only copy a function stub.
if (!behavior.isGlobalDeclaration) {
NodeUtil.getFunctionBody(fnValue).removeChildren();
}
exprResult.getFirstChild().setJSDocInfo(info.build());
block.addChildToBack(exprResult);
nameToExprResult.put(fnName, exprResult);
}
// Copy other members.
for (MemberDefinition behaviorProp : behavior.nonPropertyMembersToCopy) {
String propName = behaviorProp.name.getString();
if (nameToExprResult.containsKey(propName)) {
block.removeChild(nameToExprResult.get(propName));
}
Node exprResult = IR.exprResult(NodeUtil.newQName(compiler, qualifiedPath + propName));
exprResult.useSourceInfoFromForTree(behaviorProp.name);
JSDocInfoBuilder info = JSDocInfoBuilder.maybeCopyFrom(behaviorProp.info);
if (behaviorProp.name.isGetterDef()) {
info = new JSDocInfoBuilder(true);
if (behaviorProp.info != null && behaviorProp.info.getReturnType() != null) {
info.recordType(behaviorProp.info.getReturnType());
}
}
exprResult.getFirstChild().setJSDocInfo(info.build());
block.addChildToBack(exprResult);
nameToExprResult.put(propName, exprResult);
}
}
}
/**
* Adds the generated setter for a readonly property.
*
* @see https://www.polymer-project.org/0.8/docs/devguide/properties.html#read-only
*/
private Node makeReadOnlySetter(String propName, String qualifiedPath) {
String setterName = "_set" + propName.substring(0, 1).toUpperCase() + propName.substring(1);
Node fnNode = IR.function(IR.name(""), IR.paramList(IR.name(propName)), IR.block());
compiler.reportChangeToChangeScope(fnNode);
Node exprResNode =
IR.exprResult(IR.assign(NodeUtil.newQName(compiler, qualifiedPath + setterName), fnNode));
JSDocInfoBuilder info = new JSDocInfoBuilder(true);
// This is overriding a generated function which was added to the interface in
// {@code createExportsAndExterns}.
info.recordOverride();
exprResNode.getFirstChild().setJSDocInfo(info.build());
return exprResNode;
}
/**
* Create exports and externs to protect element properties and methods from renaming and dead
* code removal.
*
* Since Polymer templates, observers, and computed properties rely on string references to
* element properties and methods, and because we don't yet have a way to update those references
* reliably, we instead export or extern them.
*
*
For properties, we create a new interface called {@code PolymerInterface}, add
* all element properties to it, mark that the element class {@code @implements} this interface,
* and add the interface to the Closure externs. The specific set of properties we add to this
* interface is determined by the value of {@code polymerExportPolicy}.
*
* For methods, when {@code polymerExportPolicy = EXPORT_ALL}, we instead append to {@code
* Object.prototype} in the externs using {@code @export} annotations. This approach is a
* compromise, with the following alternatives considered:
*
*
Alternative 1: Add methods to our generated {@code PolymerInterface} in the
* externs. Pro: More optimal than {@code Object.prototype} when type-aware optimizations are
* enabled. Con 1: When a class {@code @implements} an interface, and when {@code
* report_missing_override} is enabled, any method on the class that is also in the interface must
* have an {@code @override} annotation, which means we generate a spurious warning for all
* methods. Con 2: An unresolved bug was encountered (b/115942961) relating to a mismatch between
* the signatures of the class and the generated interface.
*
* Alternative 2: Generate goog.exportProperty calls, which causes aliases on the prototype
* from original to optimized names to be set. Pro: Compiled code can still use the optimized
* name. Con: In practice, for Polymer applications, we see a net increase in bundle size due to
* the high number of new {@code Foo.prototype.originalName = Foo.prototype.z} expressions.
*
*
Alternative 3: Append directly to the {@code Object.prototype} externs, instead of using
* {@code @export} annotations for the {@link GenerateExports} pass. Pro: Doesn't depend on the
* {@code generate_exports} and {@code export_local_property_definitions} flags. Con: The
* PolymerPass runs in the type checking phase, so modifying {@code Object.prototype} here causes
* unwanted type checking effects, such as allowing the method to be called on any object, and
* generating incorrect warnings when {@code report_missing_override} is enabled.
*/
private void createExportsAndExterns(
final PolymerClassDefinition cls,
List readOnlyProps,
List attributeReflectedProps) {
Node block = IR.block();
String interfaceName = getInterfaceName(cls);
Node fnNode = NodeUtil.emptyFunction();
compiler.reportChangeToChangeScope(fnNode);
Node varNode = IR.var(NodeUtil.newQName(compiler, interfaceName), fnNode);
JSDocInfoBuilder info = new JSDocInfoBuilder(true);
info.recordInterface();
varNode.setJSDocInfo(info.build());
block.addChildToBack(varNode);
String interfaceBasePath = interfaceName + ".prototype.";
if (polymerExportPolicy == PolymerExportPolicy.EXPORT_ALL) {
// Properties from behaviors were added to our element definition earlier.
appendPropertiesToBlock(cls.props, block, interfaceBasePath);
// Methods from behaviors were not already added to our element definition, so we need to
// export those in addition to methods defined directly on the element. Note it's possible
// and valid for two behaviors, or a behavior and an element, to implement the same method,
// so we de-dupe by name. We're not checking that the signatures are compatible in the way
// that normal class inheritance would, but that's not easy to do since these aren't classes.
// Class mixins replace Polymer behaviors and are supported directly by Closure, so new code
// should use those instead.
LinkedHashMap uniqueMethods = new LinkedHashMap<>();
if (cls.behaviors != null) {
for (BehaviorDefinition behavior : cls.behaviors) {
for (MemberDefinition method : behavior.functionsToCopy) {
uniqueMethods.put(method.name.getString(), method);
}
}
}
for (MemberDefinition method : cls.methods) {
uniqueMethods.put(method.name.getString(), method);
}
for (MemberDefinition method : uniqueMethods.values()) {
addMethodToObjectExternsUsingExportAnnotation(cls, method);
}
} else if (polymerVersion == 1) {
// For Polymer 1, all declared properties are non-renameable
appendPropertiesToBlock(cls.props, block, interfaceBasePath);
} else {
// For Polymer 2, only read-only properties and reflectToAttribute properties are
// non-renameable. Other properties follow the ALL_UNQUOTED renaming rules.
List interfaceProperties = new ArrayList<>();
interfaceProperties.addAll(readOnlyProps);
if (attributeReflectedProps != null) {
interfaceProperties.addAll(attributeReflectedProps);
}
appendPropertiesToBlock(interfaceProperties, block, interfaceBasePath);
}
for (MemberDefinition prop : readOnlyProps) {
// Add all _set* functions to avoid renaming.
String propName = prop.name.getString();
String setterName = "_set" + propName.substring(0, 1).toUpperCase() + propName.substring(1);
Node setterExprNode =
IR.exprResult(NodeUtil.newQName(compiler, interfaceBasePath + setterName));
JSDocInfoBuilder setterInfo = new JSDocInfoBuilder(true);
JSTypeExpression propType = PolymerPassStaticUtils.getTypeFromProperty(prop, compiler);
setterInfo.recordParameter(propName, propType);
setterExprNode.getFirstChild().setJSDocInfo(setterInfo.build());
block.addChildToBack(setterExprNode);
}
block.useSourceInfoIfMissingFromForTree(polymerElementExterns);
Node scopeRoot = polymerElementExterns;
if (!scopeRoot.isScript()) {
scopeRoot = scopeRoot.getParent();
}
Node stmts = block.removeChildren();
scopeRoot.addChildrenToBack(stmts);
compiler.reportChangeToEnclosingScope(stmts);
}
/**
* Add a method to {@code Object.prototype} in the externs by inserting a {@code GETPROP}
* expression with an {@code @export} annotation into the program.
*
* This relies on the {@code --generate_exports} and {@code export_local_property_definitions}
* flags to enable the {@link GenerateExports} pass, which will add properties exported in this
* way to {@code Object.prototype} in the externs, thus preventing renaming and dead code removal.
* Note that {@link GenerateExports} runs after type checking, so extending {@code
* Object.prototype} does not cause unwanted type checking effects.
*/
private void addMethodToObjectExternsUsingExportAnnotation(
PolymerClassDefinition cls, MemberDefinition method) {
Node getprop =
NodeUtil.newQName(
compiler, cls.target.getQualifiedName() + ".prototype." + method.name.getString());
JSDocInfoBuilder info =
new JSDocInfoBuilder(
/** parseDocumentation */
true);
if (method.info != null) {
// We need to preserve visibility, but other JSDoc doesn't matter (and can cause
// re-declaration errors).
info.recordVisibility(method.info.getVisibility());
}
info.recordExport();
getprop.setJSDocInfo(info.build());
Node expression = IR.exprResult(getprop).useSourceInfoIfMissingFromForTree(method.name);
// Walk up until we find a statement we can insert after.
Node insertAfter = cls.definition;
while (!NodeUtil.isStatementBlock(insertAfter.getParent())) {
insertAfter = insertAfter.getParent();
}
insertAfter.getParent().addChildAfter(expression, insertAfter);
compiler.reportChangeToEnclosingScope(expression);
}
/** Returns the name of the generated extern interface which the element implements. */
private static String getInterfaceName(final PolymerClassDefinition cls) {
return "Polymer" + cls.target.getQualifiedName().replace('.', '_') + "Interface";
}
/** Returns an assign replacing the equivalent var or let declaration. */
private static Node varToAssign(Node var) {
Node assign =
IR.assign(var.getFirstChild().cloneNode(), var.getFirstChild().removeFirstChild());
return IR.exprResult(assign).useSourceInfoIfMissingFromForTree(var);
}
/**
* Converts property observer strings to direct function references.
*
*
From: observer: '_observerName' To:
* observer: ClassName.prototype._observerName
*/
private void convertSimpleObserverStringsToReferences(final PolymerClassDefinition cls) {
for (MemberDefinition prop : cls.props) {
if (prop.value.isObjectLit()) {
Node observer = NodeUtil.getFirstPropMatchingKey(prop.value, "observer");
if (observer != null && observer.isString()) {
Node observerDirectReference =
IR.getprop(cls.target.cloneTree(), "prototype", observer.getString())
.useSourceInfoFrom(observer);
observer.replaceWith(observerDirectReference);
compiler.reportChangeToEnclosingScope(observerDirectReference);
}
}
}
}
/**
* For any property in the Polymer property configuration object with a `computed` key, parse the
* method call and path arguments and replace them with property reflection calls.
*
*
Returns a list of property sink statements to guard against dead code elimination since the
* compiler may not see these methods as being used.
*/
private List addComputedPropertiesReflectionCalls(final PolymerClassDefinition cls) {
List propertySinkStatements = new ArrayList<>();
for (MemberDefinition prop : cls.props) {
if (prop.value.isObjectLit()) {
Node computed = NodeUtil.getFirstPropMatchingKey(prop.value, "computed");
if (computed != null && computed.isString()) {
propertySinkStatements.addAll(
replaceMethodStringWithReflectedCalls(cls.target, computed));
}
}
}
return propertySinkStatements;
}
/**
* For any strings returned in the array from the Polymer static observers property, parse the
* method call and path arguments and replace them with property reflection calls.
*
* Returns a list of property sink statements to guard against dead code elimination since the
* compiler may not see these methods as being used.
*/
private List addComplexObserverReflectionCalls(final PolymerClassDefinition cls) {
List propertySinkStatements = new ArrayList<>();
Node classMembers = NodeUtil.getClassMembers(cls.definition);
Node getter = NodeUtil.getFirstGetterMatchingKey(classMembers, "observers");
if (getter != null) {
Node complexObservers = null;
for (Node child : NodeUtil.getFunctionBody(getter.getFirstChild()).children()) {
if (child.isReturn()) {
if (child.hasChildren() && child.getFirstChild().isArrayLit()) {
complexObservers = child.getFirstChild();
break;
}
}
}
if (complexObservers != null) {
for (Node complexObserver : complexObservers.children()) {
if (complexObserver.isString()) {
propertySinkStatements.addAll(
replaceMethodStringWithReflectedCalls(cls.target, complexObserver));
}
}
}
}
return propertySinkStatements;
}
/**
* Given a Polymer method call string such as: "methodName(path.item, other.property.path)"
* parses the string into a method name and arguments and builds up a new string of
* property reflection calls so that the properties can be renamed consistently.
*
* Returns a list of property sink statements to guard against dead code elimination.
*/
private List replaceMethodStringWithReflectedCalls(Node className, Node methodSignature) {
checkArgument(methodSignature.isString());
List propertySinkStatements = new ArrayList<>();
String methodSignatureString = methodSignature.getString().trim();
int openParenIndex = methodSignatureString.indexOf('(');
if (methodSignatureString.charAt(methodSignatureString.length() - 1) != ')'
|| openParenIndex < 1) {
compiler.report(JSError.make(methodSignature, PolymerPassErrors.POLYMER_UNPARSABLE_STRING));
return propertySinkStatements;
}
// Reflect property calls require an instance of a type. Since we don't have one,
// just cast an object literal to be that type. While not generally safe, it is
// safe for property reflection.
JSDocInfoBuilder classTypeDoc = new JSDocInfoBuilder(false);
JSTypeExpression classType =
new JSTypeExpression(
new Node(Token.BANG, IR.string(className.getQualifiedName())),
className.getSourceFileName());
classTypeDoc.recordType(classType);
Node classTypeExpression = IR.cast(IR.objectlit(), classTypeDoc.build());
// Add reflect and property sinks for the method name which will be a property on the class
String methodName = methodSignatureString.substring(0, openParenIndex).trim();
propertySinkStatements.add(
IR.getprop(className.cloneTree(), "prototype", methodName)
.useSourceInfoFromForTree(methodSignature));
Node reflectedMethodName =
IR.call(
IR.getprop(IR.name("$jscomp"), IR.string("reflectProperty")),
IR.string(methodName),
classTypeExpression.cloneTree());
Node reflectedSignature = reflectedMethodName;
// Process any parameters in the method call
String nextParamDelimeter = "(";
if (openParenIndex < methodSignatureString.length() - 2) {
String methodParamsString =
methodSignatureString
.substring(openParenIndex + 1, methodSignatureString.length() - 1)
.trim();
List methodParams = parseMethodParams(methodParamsString, methodSignature);
// Add property reflection for each parameter
for (String methodParam : methodParams) {
Node reflectedTypeReference = classTypeExpression;
if (methodParam.length() == 0) {
continue;
}
if (isParamLiteral(methodParam)) {
Node term = IR.string(methodParam);
reflectedSignature =
IR.add(IR.add(reflectedSignature, IR.string(nextParamDelimeter)), term);
} else {
// Arguments in conmplex observer or computed property strings are property paths.
// We need to rename each path segment.
List paramParts = Splitter.on('.').splitToList(methodParam);
String nextPropertyTermDelimiter = nextParamDelimeter;
for (int i = 0; i < paramParts.size(); i++) {
// Polymer property paths have two special terms recognized when they are the last
// path reference:
// - * - any sub-property change
// - splices - Adds or removes of array items
// These terms are not renamable and are left as is
if (i > 0
&& i == paramParts.size() - 1
&& (paramParts.get(i).equals("*") || paramParts.get(i).equals("splices"))) {
reflectedSignature =
IR.add(
reflectedSignature, IR.string(nextPropertyTermDelimiter + paramParts.get(i)));
} else {
if (i == 0) {
// The root of the parameter will be a property reference on the class
// Create both a property sink and a reflection call
propertySinkStatements.add(
IR.getprop(
className.cloneTree(),
IR.string("prototype"),
IR.string(paramParts.get(i)))
.useSourceInfoFromForTree(methodSignature));
}
Node reflectedParamPart =
IR.call(
IR.getprop(IR.name("$jscomp"), IR.string("reflectProperty")),
IR.string(paramParts.get(i)),
reflectedTypeReference.cloneTree());
reflectedSignature =
IR.add(
IR.add(reflectedSignature, IR.string(nextPropertyTermDelimiter)),
reflectedParamPart);
reflectedTypeReference =
IR.getprop(reflectedTypeReference.cloneTree(), paramParts.get(i));
}
nextPropertyTermDelimiter = ".";
}
}
nextParamDelimeter = ",";
}
if (methodParams.size() == 0) {
reflectedSignature = IR.add(reflectedSignature, IR.string("()"));
} else {
reflectedSignature = IR.add(reflectedSignature, IR.string(")"));
}
} else {
reflectedSignature = IR.add(reflectedSignature, IR.string("()"));
}
methodSignature.replaceWith(reflectedSignature.useSourceInfoFromForTree(methodSignature));
compiler.reportChangeToEnclosingScope(reflectedSignature);
return propertySinkStatements;
}
/**
* Parses the parameters string from a complex observer or computed property into distinct
* parameters. Since a parameter can be a quoted string literal, we can't just split on commas.
*/
private List parseMethodParams(String methodParameters, Node methodSignature) {
List parsedParameters = new ArrayList<>();
char nextDelimeter = ',';
String currentTerm = "";
for (int i = 0; i < methodParameters.length(); i++) {
if (methodParameters.charAt(i) == nextDelimeter) {
if (nextDelimeter == ',') {
parsedParameters.add(currentTerm.trim());
currentTerm = "";
} else {
currentTerm += nextDelimeter;
nextDelimeter = ',';
}
} else {
currentTerm += methodParameters.charAt(i);
if (methodParameters.charAt(i) == '"' || methodParameters.charAt(i) == '\'') {
nextDelimeter = methodParameters.charAt(i);
}
}
}
if (nextDelimeter != ',') {
compiler.report(JSError.make(methodSignature, PolymerPassErrors.POLYMER_UNPARSABLE_STRING));
return parsedParameters;
}
if (currentTerm.length() > 0) {
parsedParameters.add(currentTerm.trim());
}
return parsedParameters;
}
/** Determine if the method parameter a quoted string or numeric literal recognized by Polymer. */
private static boolean isParamLiteral(String param) {
try {
Double.parseDouble(param);
return true;
} catch (NumberFormatException e) {
// Check to see if the parameter is a literal - either a quoted string or
// numeric literal
if (param.length() > 1
&& (param.charAt(0) == '"' || param.charAt(0) == '\'')
&& param.charAt(0) == param.charAt(param.length() - 1)) {
return true;
}
}
return false;
}
}