1/*
2 * Copyright (C) 2009 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.ant;
18
19import com.android.xml.AndroidXPathFactory;
20
21import org.apache.tools.ant.BuildException;
22import org.apache.tools.ant.Task;
23import org.apache.tools.ant.types.Path;
24import org.xml.sax.InputSource;
25
26import java.io.FileInputStream;
27import java.io.FileNotFoundException;
28
29import javax.xml.xpath.XPath;
30import javax.xml.xpath.XPathExpressionException;
31
32/**
33 * Android specific XPath task.
34 * The goal is to get the result of an XPath expression on Android XML files. The android namespace
35 * (http://schemas.android.com/apk/res/android) must be associated to the "android" prefix.
36 */
37public class XPathTask extends Task {
38
39    private Path mManifestFile;
40    private String mProperty;
41    private String mExpression;
42    private String mDefault;
43
44    public void setInput(Path manifestFile) {
45        mManifestFile = manifestFile;
46    }
47
48    public void setOutput(String property) {
49        mProperty = property;
50    }
51
52    public void setExpression(String expression) {
53        mExpression = expression;
54    }
55
56    public void setDefault(String defaultValue) {
57        mDefault = defaultValue;
58    }
59
60    @Override
61    public void execute() throws BuildException {
62        try {
63            if (mManifestFile == null || mManifestFile.list().length == 0) {
64                throw new BuildException("input attribute is missing!");
65            }
66
67            if (mProperty == null) {
68                throw new BuildException("output attribute is missing!");
69            }
70
71            if (mExpression == null) {
72                throw new BuildException("expression attribute is missing!");
73            }
74
75            XPath xpath = AndroidXPathFactory.newXPath();
76
77            String file = mManifestFile.list()[0];
78            String result = xpath.evaluate(mExpression, new InputSource(new FileInputStream(file)));
79            if (result.length() == 0 && mDefault != null) {
80                result = mDefault;
81            }
82
83            getProject().setProperty(mProperty, result);
84        } catch (XPathExpressionException e) {
85            throw new BuildException(e);
86        } catch (FileNotFoundException e) {
87            throw new BuildException(e);
88        }
89    }
90}
91