com.android.manifmerger.PlaceholderHandler Maven / Gradle / Ivy
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/*
* Copyright (C) 2014 The Android Open Source Project
*
* 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.android.manifmerger;
import com.android.annotations.NonNull;
import com.android.annotations.Nullable;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Replaces all placeholders of the form ${name} with a tool invocation provided value
*/
public class PlaceholderHandler {
// interesting placeholders names that are documented to be automatically provided.
public static final String INSTRUMENTATION_RUNNER = "instrumentationRunner";
public static final String PACKAGE_NAME = "packageName";
public static final String APPLICATION_ID = "applicationId";
// regular expression to recognize placeholders like ${name}, potentially surrounded by a
// prefix and suffix string. this will split in 3 groups, the prefix, the placeholder name, and
// the suffix.
private static final Pattern PATTERN = Pattern.compile("([^\\$]*)\\$\\{([^\\}]*)\\}(.*)");
/**
* Interface to provide a value for a placeholder key.
* @param the key type
*/
public interface KeyBasedValueResolver {
/**
* Returns a placeholder value for the placeholder key or null if none exists.
*/
@Nullable
String getValue(@NonNull T key);
}
/**
* Returns true if the passed string is a placeholder value, false otherwise.
*/
public static boolean isPlaceHolder(@NonNull String string) {
return PATTERN.matcher(string).matches();
}
/**
* Visits a document's entire tree and check each attribute for a placeholder existence.
* If one is found, delegate to the provided {@link KeyBasedValueResolver} to provide a value
* for the placeholder.
*
* If no value is provided, an error will be generated.
*
* @param xmlDocument the xml document to visit
* @param valueProvider the placeholder value provider.
* @param mergingReportBuilder to report errors and log actions.
*/
public void visit(
@NonNull ManifestMerger2.MergeType mergeType,
@NonNull XmlDocument xmlDocument,
@NonNull KeyBasedValueResolver valueProvider,
@NonNull MergingReport.Builder mergingReportBuilder) {
visit(mergeType, xmlDocument.getRootNode(), valueProvider, mergingReportBuilder);
}
private void visit(
@NonNull ManifestMerger2.MergeType mergeType,
@NonNull XmlElement xmlElement,
@NonNull KeyBasedValueResolver valueProvider,
@NonNull MergingReport.Builder mergingReportBuilder) {
for (XmlAttribute xmlAttribute : xmlElement.getAttributes()) {
Matcher matcher = PATTERN.matcher(xmlAttribute.getValue());
if (matcher.matches()) {
String placeholderValue = valueProvider.getValue(matcher.group(2));
if (placeholderValue == null) {
// if this is a library, ignore the failure
MergingReport.Record.Severity severity =
mergeType == ManifestMerger2.MergeType.LIBRARY
? MergingReport.Record.Severity.INFO
: MergingReport.Record.Severity.ERROR;
xmlAttribute.addMessage(mergingReportBuilder, severity,
String.format(
"Attribute %1$s at %2$s requires a placeholder substitution"
+ " but no value for <%3$s> is provided.",
xmlAttribute.getId(),
xmlAttribute.printPosition(),
matcher.group(2)
));
} else {
// record the attribute set
mergingReportBuilder.getActionRecorder().recordAttributeAction(
xmlAttribute,
PositionImpl.UNKNOWN,
Actions.ActionType.INJECTED,
null /* attributeOperationType */);
String attrValue = matcher.group(1) + placeholderValue + matcher.group(3);
xmlAttribute.getXml().setValue(attrValue);
}
}
}
for (XmlElement childElement : xmlElement.getMergeableElements()) {
visit(mergeType, childElement, valueProvider, mergingReportBuilder);
}
}
}