src/ast/Indexer.js
/*
* Copyright 2002-2015 the original author or 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.
*/
import {SpelNode} from './SpelNode';
import {Stack} from '../lib/Stack';
/**
* An Indexer can index into some proceeding structure to access a particular piece of it.
* Supported structures are: strings / collections (lists/sets) / arrays.
*
* @author Andy Clement
* @author Phillip Webb
* @author Stephane Nicoll
* @author Ben March
* @since 0.2.0
*/
function createNode(position, expressionComponents) {
var node = SpelNode.create.apply(null, ['indexer', position].concat(expressionComponents));
node.getValue = function (state) {
var activeContext = state.activeContext,
context,
childrenCount = node.getChildren().length,
i,
value;
state.activeContext = new Stack();
state.activeContext.push(state.rootContext);
context = state.activeContext.peek();
if (!context) {
throw {
name: 'ContextDoesNotExistException',
message: 'Attempting to evaluate compound expression with an undefined context.'
};
}
for (i = 0; i < childrenCount; i += 1) {
state.activeContext.push(node.getChildren()[i].getValue(state));
}
value = state.activeContext.peek();
for (i = 0; i < childrenCount; i += 1) {
state.activeContext.pop();
}
state.activeContext = activeContext;
return value;
};
//node.setContext(node.getValue());
return node;
}
export var Indexer = {
create: createNode
};