src/ast/MethodReference.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'
/**
* Expression language AST node that represents a method reference.
*
* @author Andy Clement
* @author Juergen Hoeller
* @author Ben March
* @since 0.2.0
*/
function createNode(nullSafeNavigation, methodName, position, args) {
var node = SpelNode.create('method', position);
node.getRaw = function () {
return {
methodName,
args
};
};
node.getValue = function (state) {
var context = state.activeContext.peek(),
compiledArgs = [],
method;
if (!context) {
throw {
name: 'ContextDoesNotExistException',
message: 'Attempting to look up property \''+ methodName +'\' for an undefined context.'
};
}
//handle safe navigation
function maybeHandleNullSafeNavigation(member) {
if (member === undefined || member === null) {
if (nullSafeNavigation) {
return null;
}
throw {
name: 'NullPointerException',
message: 'Method ' + methodName + ' does not exist.'
};
}
return member;
}
//populate arguments
args.forEach(function (arg) {
// reset the active context to root context for evaluating argument
const currentActiveContext = state.activeContext
state.activeContext = new Stack();
state.activeContext.push(state.rootContext);
// evaluate argument
compiledArgs.push(arg.getValue(state));
// reset the active context
state.activeContext = currentActiveContext;
});
//accessors might not be available
if (methodName.substr(0, 3) === 'get' && !context[methodName]) {
return maybeHandleNullSafeNavigation(context[methodName.charAt(3).toLowerCase() + methodName.substring(4)]);
}
if (methodName.substr(0, 3) === 'set' && !context[methodName]) {
/*jshint -W093 */
return context[methodName.charAt(3).toLowerCase() + methodName.substring(4)] = compiledArgs[0];
/*jshint +W093 */
}
//array methods
if (Array.isArray(context)) {
//size() -> length
if (methodName === 'size') {
return context.length;
}
if (methodName === 'contains') {
return context.includes(compiledArgs[0])
}
}
method = maybeHandleNullSafeNavigation(context[methodName]);
if (method) {
return method.apply(context, compiledArgs);
}
return null;
};
return node;
}
export var MethodReference = {
create: createNode
};