/**
* Expand a jQuery.expandedEach call
*
* <p>Expanded jQuery.expandedEach calls will replace the GETELEM nodes of a property assignment
* with GETPROP nodes to allow for renaming.
*/
private void maybeExpandJqueryEachCall(NodeTraversal t, Node n) {
Node objectToLoopOver = n.getChildAtIndex(1);
if (objectToLoopOver == null) {
return;
}
Node callbackFunction = objectToLoopOver.getNext();
if (callbackFunction == null || !callbackFunction.isFunction()) {
return;
}
// Run the peephole optimizations on the first argument to handle
// cases like ("a " + "b").split(" ")
peepholePasses.process(null, n.getChildAtIndex(1));
// Create a reference tree
Node nClone = n.cloneTree();
objectToLoopOver = nClone.getChildAtIndex(1);
// Check to see if the first argument is something we recognize and can
// expand.
if (!objectToLoopOver.isObjectLit()
&& !(objectToLoopOver.isArrayLit() && isArrayLitValidForExpansion(objectToLoopOver))) {
t.report(n, JQUERY_UNABLE_TO_EXPAND_INVALID_LIT_ERROR, (String) null);
return;
}
// Find all references to the callback function arguments
List<Node> keyNodeReferences = new ArrayList<>();
List<Node> valueNodeReferences = new ArrayList<>();
new NodeTraversal(
compiler,
new FindCallbackArgumentReferences(
callbackFunction,
keyNodeReferences,
valueNodeReferences,
objectToLoopOver.isArrayLit()))
.traverseInnerNode(
NodeUtil.getFunctionBody(callbackFunction), callbackFunction, t.getScope());
if (keyNodeReferences.isEmpty()) {
// We didn't do anything useful ...
t.report(n, JQUERY_USELESS_EACH_EXPANSION, (String) null);
return;
}
Node fncBlock =
tryExpandJqueryEachCall(
t, nClone, callbackFunction, keyNodeReferences, valueNodeReferences);
if (fncBlock != null && fncBlock.hasChildren()) {
replaceOriginalJqueryEachCall(n, fncBlock);
} else {
// We didn't do anything useful ...
t.report(n, JQUERY_USELESS_EACH_EXPANSION, (String) null);
}
}
private Node tryExpandJqueryEachCall(
NodeTraversal t, Node n, Node callbackFunction, List<Node> keyNodes, List<Node> valueNodes) {
Node callTarget = n.getFirstChild();
Node objectToLoopOver = callTarget.getNext();
// New block to contain the expanded statements
Node fncBlock = IR.block().srcref(callTarget);
boolean isValidExpansion = true;
// Expand the jQuery.expandedEach call
Node key = objectToLoopOver.getFirstChild(), val = null;
for (int i = 0; key != null; key = key.getNext(), i++) {
if (key != null) {
if (objectToLoopOver.isArrayLit()) {
// Arrays have a value of their index number
val = IR.number(i).srcref(key);
} else {
val = key.getFirstChild();
}
}
// Keep track of the replaced nodes so we can reset the tree
List<Node> newKeys = new ArrayList<>();
List<Node> newValues = new ArrayList<>();
List<Node> origGetElems = new ArrayList<>();
List<Node> newGetProps = new ArrayList<>();
// Replace all of the key nodes with the prop name
for (int j = 0; j < keyNodes.size(); j++) {
Node origNode = keyNodes.get(j);
Node ancestor = origNode.getParent();
Node newNode = IR.string(key.getString()).srcref(key);
newKeys.add(newNode);
ancestor.replaceChild(origNode, newNode);
// Walk up the tree to see if the key is used in a GETELEM
// assignment
while (ancestor != null && !NodeUtil.isStatement(ancestor) && !ancestor.isGetElem()) {
ancestor = ancestor.getParent();
}
// Convert GETELEM nodes to GETPROP nodes so that they can be
// renamed or removed.
if (ancestor != null && ancestor.isGetElem()) {
Node propObject = ancestor;
while (propObject.isGetProp() || propObject.isGetElem()) {
propObject = propObject.getFirstChild();
}
Node ancestorClone = ancestor.cloneTree();
// Run the peephole passes to handle cases such as
// obj['lit' + key] = val;
peepholePasses.process(null, ancestorClone.getChildAtIndex(1));
Node prop = ancestorClone.getChildAtIndex(1);
if (prop.isString()
&& NodeUtil.isValidPropertyName(LanguageMode.ECMASCRIPT3, prop.getString())) {
Node target = ancestorClone.getFirstChild();
Node newGetProp = IR.getprop(target.detachFromParent(), prop.detachFromParent());
newGetProps.add(newGetProp);
origGetElems.add(ancestor);
ancestor.getParent().replaceChild(ancestor, newGetProp);
} else {
if (prop.isString()
&& !NodeUtil.isValidPropertyName(LanguageMode.ECMASCRIPT3, prop.getString())) {
t.report(n, JQUERY_UNABLE_TO_EXPAND_INVALID_NAME_ERROR, prop.getString());
}
isValidExpansion = false;
}
}
}
if (isValidExpansion) {
// Replace all of the value nodes with the prop value
for (int j = 0; val != null && j < valueNodes.size(); j++) {
Node origNode = valueNodes.get(j);
Node newNode = val.cloneTree();
newValues.add(newNode);
origNode.getParent().replaceChild(origNode, newNode);
}
// Wrap the new tree in an anonymous function call
Node fnc =
IR.function(
IR.name("").srcref(key),
IR.paramList().srcref(key),
callbackFunction.getChildAtIndex(2).cloneTree())
.srcref(key);
Node call = IR.call(fnc).srcref(key);
call.putBooleanProp(Node.FREE_CALL, true);
fncBlock.addChildToBack(IR.exprResult(call).srcref(call));
}
// Reset the source tree
for (int j = 0; j < newGetProps.size(); j++) {
newGetProps.get(j).getParent().replaceChild(newGetProps.get(j), origGetElems.get(j));
}
for (int j = 0; j < newKeys.size(); j++) {
newKeys.get(j).getParent().replaceChild(newKeys.get(j), keyNodes.get(j));
}
for (int j = 0; j < newValues.size(); j++) {
newValues.get(j).getParent().replaceChild(newValues.get(j), valueNodes.get(j));
}
if (!isValidExpansion) {
return null;
}
}
return fncBlock;
}