src/util/xml-helpers.js - cordova-common - Git at Google

 /**
     Licensed to the Apache Software Foundation (ASF) under one
     or more contributor license agreements.  See the NOTICE file
     distributed with this work for additional information
     regarding copyright ownership.  The ASF licenses this file
     to you 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.
 */

 /**
  * contains XML utility functions, some of which are specific to elementtree
  */

 const fs = require('fs-extra');
 const path = require('path');
 const _ = require('underscore');
 const et = require('elementtree');
 const stripBom = require('strip-bom');

 const ROOT = /^\/([^/]*)/;
 const ABSOLUTE = /^\/([^/]*)\/(.*)/;

 module.exports = {
     // compare two et.XML nodes, see if they match
     // compares tagName, text, attributes and children (recursively)
     equalNodes: function (one, two) {
         if (one.tag !== two.tag) {
             return false;
         } else if (one.text.trim() !== two.text.trim()) {
             return false;
         } else if (one._children.length !== two._children.length) {
             return false;
         }

         if (!attribMatch(one, two)) return false;

         for (let i = 0; i < one._children.length; i++) {
             if (!module.exports.equalNodes(one._children[i], two._children[i])) {
                 return false;
             }
         }

         return true;
     },

     // adds node to doc at selector, creating parent if it doesn't exist
     graftXML: function (doc, nodes, selector, after) {
         let parent = module.exports.resolveParent(doc, selector);
         if (!parent) {
             // Try to create the parent recursively if necessary
             try {
                 const parentToCreate = et.XML('<' + path.basename(selector) + '/>');
                 const parentSelector = path.dirname(selector);

                 this.graftXML(doc, [parentToCreate], parentSelector);
             } catch (e) {
                 return false;
             }
             parent = module.exports.resolveParent(doc, selector);
             if (!parent) return false;
         }

         nodes.forEach(node => {
             // check if child is unique first
             if (uniqueChild(node, parent)) {
                 const children = parent.getchildren();
                 const insertIdx = after ? findInsertIdx(children, after) : children.length;

                 // TODO: replace with parent.insert after the bug in ElementTree is fixed
                 parent.getchildren().splice(insertIdx, 0, node);
             }
         });

         return true;
     },

     // adds new attributes to doc at selector
     // Will only merge if attribute has not been modified already or --force is used
     graftXMLMerge: function (doc, nodes, selector, xml) {
         const target = module.exports.resolveParent(doc, selector);
         if (!target) return false;

         // saves the attributes of the original xml before making changes
         xml.oldAttrib = _.extend({}, target.attrib);

         nodes.forEach(node => {
             const attributes = node.attrib;
             for (const attribute in attributes) {
                 target.attrib[attribute] = node.attrib[attribute];
             }
         });

         return true;
     },

     // overwrite all attributes to doc at selector with new attributes
     // Will only overwrite if attribute has not been modified already or --force is used
     graftXMLOverwrite: function (doc, nodes, selector, xml) {
         const target = module.exports.resolveParent(doc, selector);
         if (!target) return false;

         // saves the attributes of the original xml before making changes
         xml.oldAttrib = _.extend({}, target.attrib);

         // remove old attributes from target
         const targetAttributes = target.attrib;
         for (const targetAttribute in targetAttributes) {
             delete targetAttributes[targetAttribute];
         }

         // add new attributes to target
         nodes.forEach(node => {
             const attributes = node.attrib;
             for (const attribute in attributes) {
                 target.attrib[attribute] = node.attrib[attribute];
             }
         });

         return true;
     },

     // removes node from doc at selector
     pruneXML: function (doc, nodes, selector) {
         const parent = module.exports.resolveParent(doc, selector);
         if (!parent) return false;

         nodes.forEach(node => {
             const matchingKid = findChild(node, parent);
             if (matchingKid !== undefined) {
                 // stupid elementtree takes an index argument it doesn't use
                 // and does not conform to the python lib
                 parent.remove(matchingKid);
             }
         });

         return true;
     },

     // restores attributes from doc at selector
     pruneXMLRestore: function (doc, selector, xml) {
         const target = module.exports.resolveParent(doc, selector);
         if (!target) return false;

         if (xml.oldAttrib) {
             target.attrib = _.extend({}, xml.oldAttrib);
         }

         return true;
     },

     pruneXMLRemove: function (doc, selector, nodes) {
         const target = module.exports.resolveParent(doc, selector);
         if (!target) return false;

         nodes.forEach(node => {
             const attributes = node.attrib;
             for (const attribute in attributes) {
                 if (target.attrib[attribute]) {
                     delete target.attrib[attribute];
                 }
             }
         });

         return true;
     },

     parseElementtreeSync: function (filename) {
         const contents = stripBom(fs.readFileSync(filename, 'utf-8'));
         return new et.ElementTree(et.XML(contents));
     },

     resolveParent: function (doc, selector) {
         let parent, tagName, subSelector;

         // handle absolute selector (which elementtree doesn't like)
         if (ROOT.test(selector)) {
             tagName = selector.match(ROOT)[1];
             // test for wildcard "any-tag" root selector
             if (tagName === '*' || tagName === doc._root.tag) {
                 parent = doc._root;

                 // could be an absolute path, but not selecting the root
                 if (ABSOLUTE.test(selector)) {
                     subSelector = selector.match(ABSOLUTE)[2];
                     parent = parent.find(subSelector);
                 }
             } else {
                 return false;
             }
         } else {
             parent = doc.find(selector);
         }
         return parent;
     }
 };

 function findChild (node, parent) {
     const matches = parent.findall(node.tag);
     return matches.find(m => module.exports.equalNodes(node, m));
 }

 function uniqueChild (node, parent) {
     return !findChild(node, parent);
 }

 // Find the index at which to insert an entry. After is a ;-separated priority list
 // of tags after which the insertion should be made. E.g. If we need to
 // insert an element C, and the rule is that the order of children has to be
 // As, Bs, Cs. After will be equal to "C;B;A".
 function findInsertIdx (children, after) {
     const childrenTags = children.map(child => child.tag);
     const afters = after.split(';');
     const afterIndexes = afters.map(current => childrenTags.lastIndexOf(current));
     const foundIndex = _.find(afterIndexes, index => index !== -1);

     // add to the beginning if no matching nodes are found
     return typeof foundIndex === 'undefined' ? 0 : foundIndex + 1;
 }

 const BLACKLIST = ['platform', 'feature', 'plugin', 'engine'];
 const SINGLETONS = ['content', 'author', 'name'];
 function mergeXml (src, dest, platform, clobber) {
     // Do nothing for blacklisted tags.
     if (BLACKLIST.includes(src.tag)) return;

     // Handle attributes
     Object.getOwnPropertyNames(src.attrib).forEach(attribute => {
         if (clobber || !dest.attrib[attribute]) {
             dest.attrib[attribute] = src.attrib[attribute];
         }
     });
     // Handle text
     if (src.text && (clobber || !dest.text)) {
         dest.text = src.text;
     }
     // Handle children
     src.getchildren().forEach(mergeChild);

     // Handle platform
     if (platform) {
         src.findall('platform[@name="' + platform + '"]').forEach(platformElement => {
             platformElement.getchildren().forEach(mergeChild);
         });
     }

     // Handle duplicate preference tags (by name attribute)
     removeDuplicatePreferences(dest);

     function mergeChild (srcChild) {
         const srcTag = srcChild.tag;
         let destChild = new et.Element(srcTag);
         let foundChild;
         const query = srcTag + '';
         let shouldMerge = true;

         if (BLACKLIST.includes(srcTag)) return;

         if (SINGLETONS.includes(srcTag)) {
             foundChild = dest.find(query);
             if (foundChild) {
                 destChild = foundChild;
                 dest.remove(destChild);
             }
         } else {
             // Check for an exact match and if you find one don't add
             const mergeCandidates = dest.findall(query)
                 .filter(foundChild =>
                     foundChild && textMatch(srcChild, foundChild) && attribMatch(srcChild, foundChild)
                 );

             if (mergeCandidates.length > 0) {
                 destChild = mergeCandidates[0];
                 dest.remove(destChild);
                 shouldMerge = false;
             }
         }

         mergeXml(srcChild, destChild, platform, clobber && shouldMerge);
         dest.append(destChild);
     }

     function removeDuplicatePreferences (xml) {
         // reduce preference tags to a hashtable to remove dupes
         const prefHash = xml.findall('preference[@name][@value]').reduce((previousValue, currentValue) => {
             previousValue[currentValue.attrib.name] = currentValue.attrib.value;
             return previousValue;
         }, {});

         // remove all preferences
         xml.findall('preference[@name][@value]').forEach(pref => {
             xml.remove(pref);
         });

         // write new preferences
         Object.keys(prefHash).forEach(function (key) {
             const element = et.SubElement(xml, 'preference');
             element.set('name', key);
             element.set('value', this[key]);
         }, prefHash);
     }
 }

 // Expose for testing.
 module.exports.mergeXml = mergeXml;

 function textMatch (elm1, elm2) {
     const text1 = elm1.text ? elm1.text.replace(/\s+/, '') : '';
     const text2 = elm2.text ? elm2.text.replace(/\s+/, '') : '';
     return (text1 === '' || text1 === text2);
 }

 function attribMatch (one, two) {
     const oneAttribKeys = Object.keys(one.attrib);
     const twoAttribKeys = Object.keys(two.attrib);

     if (oneAttribKeys.length !== twoAttribKeys.length) {
         return false;
     }

     for (let i = 0; i < oneAttribKeys.length; i++) {
         const attribName = oneAttribKeys[i];

         if (one.attrib[attribName] !== two.attrib[attribName]) {
             return false;
         }
     }

     return true;
 }
	/**
	Licensed to the Apache Software Foundation (ASF) under one
	or more contributor license agreements. See the NOTICE file
	distributed with this work for additional information
	regarding copyright ownership. The ASF licenses this file
	to you 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.
	*/

	/**
	* contains XML utility functions, some of which are specific to elementtree
	*/

	const fs = require('fs-extra');
	const path = require('path');
	const _ = require('underscore');
	const et = require('elementtree');
	const stripBom = require('strip-bom');

	const ROOT = /^\/([^/]*)/;
	const ABSOLUTE = /^\/([^/])\/(.)/;

	module.exports = {
	// compare two et.XML nodes, see if they match
	// compares tagName, text, attributes and children (recursively)
	equalNodes: function (one, two) {
	if (one.tag !== two.tag) {
	return false;
	} else if (one.text.trim() !== two.text.trim()) {
	return false;
	} else if (one._children.length !== two._children.length) {
	return false;
	}

	if (!attribMatch(one, two)) return false;

	for (let i = 0; i < one._children.length; i++) {
	if (!module.exports.equalNodes(one._children[i], two._children[i])) {
	return false;
	}
	}

	return true;
	},

	// adds node to doc at selector, creating parent if it doesn't exist
	graftXML: function (doc, nodes, selector, after) {
	let parent = module.exports.resolveParent(doc, selector);
	if (!parent) {
	// Try to create the parent recursively if necessary
	try {
	const parentToCreate = et.XML('<' + path.basename(selector) + '/>');
	const parentSelector = path.dirname(selector);

	this.graftXML(doc, [parentToCreate], parentSelector);
	} catch (e) {
	return false;
	}
	parent = module.exports.resolveParent(doc, selector);
	if (!parent) return false;
	}

	nodes.forEach(node => {
	// check if child is unique first
	if (uniqueChild(node, parent)) {
	const children = parent.getchildren();
	const insertIdx = after ? findInsertIdx(children, after) : children.length;

	// TODO: replace with parent.insert after the bug in ElementTree is fixed
	parent.getchildren().splice(insertIdx, 0, node);
	}
	});

	return true;
	},

	// adds new attributes to doc at selector
	// Will only merge if attribute has not been modified already or --force is used
	graftXMLMerge: function (doc, nodes, selector, xml) {
	const target = module.exports.resolveParent(doc, selector);
	if (!target) return false;

	// saves the attributes of the original xml before making changes
	xml.oldAttrib = _.extend({}, target.attrib);

	nodes.forEach(node => {
	const attributes = node.attrib;
	for (const attribute in attributes) {
	target.attrib[attribute] = node.attrib[attribute];
	}
	});

	return true;
	},

	// overwrite all attributes to doc at selector with new attributes
	// Will only overwrite if attribute has not been modified already or --force is used
	graftXMLOverwrite: function (doc, nodes, selector, xml) {
	const target = module.exports.resolveParent(doc, selector);
	if (!target) return false;

	// saves the attributes of the original xml before making changes
	xml.oldAttrib = _.extend({}, target.attrib);

	// remove old attributes from target
	const targetAttributes = target.attrib;
	for (const targetAttribute in targetAttributes) {
	delete targetAttributes[targetAttribute];
	}

	// add new attributes to target
	nodes.forEach(node => {
	const attributes = node.attrib;
	for (const attribute in attributes) {
	target.attrib[attribute] = node.attrib[attribute];
	}
	});

	return true;
	},

	// removes node from doc at selector
	pruneXML: function (doc, nodes, selector) {
	const parent = module.exports.resolveParent(doc, selector);
	if (!parent) return false;

	nodes.forEach(node => {
	const matchingKid = findChild(node, parent);
	if (matchingKid !== undefined) {
	// stupid elementtree takes an index argument it doesn't use
	// and does not conform to the python lib
	parent.remove(matchingKid);
	}
	});

	return true;
	},

	// restores attributes from doc at selector
	pruneXMLRestore: function (doc, selector, xml) {
	const target = module.exports.resolveParent(doc, selector);
	if (!target) return false;

	if (xml.oldAttrib) {
	target.attrib = _.extend({}, xml.oldAttrib);
	}

	return true;
	},

	pruneXMLRemove: function (doc, selector, nodes) {
	const target = module.exports.resolveParent(doc, selector);
	if (!target) return false;

	nodes.forEach(node => {
	const attributes = node.attrib;
	for (const attribute in attributes) {
	if (target.attrib[attribute]) {
	delete target.attrib[attribute];
	}
	}
	});

	return true;
	},

	parseElementtreeSync: function (filename) {
	const contents = stripBom(fs.readFileSync(filename, 'utf-8'));
	return new et.ElementTree(et.XML(contents));
	},

	resolveParent: function (doc, selector) {
	let parent, tagName, subSelector;

	// handle absolute selector (which elementtree doesn't like)
	if (ROOT.test(selector)) {
	tagName = selector.match(ROOT)[1];
	// test for wildcard "any-tag" root selector
	if (tagName === '*' \|\| tagName === doc._root.tag) {
	parent = doc._root;

	// could be an absolute path, but not selecting the root
	if (ABSOLUTE.test(selector)) {
	subSelector = selector.match(ABSOLUTE)[2];
	parent = parent.find(subSelector);
	}
	} else {
	return false;
	}
	} else {
	parent = doc.find(selector);
	}
	return parent;
	}
	};

	function findChild (node, parent) {
	const matches = parent.findall(node.tag);
	return matches.find(m => module.exports.equalNodes(node, m));
	}

	function uniqueChild (node, parent) {
	return !findChild(node, parent);
	}

	// Find the index at which to insert an entry. After is a ;-separated priority list
	// of tags after which the insertion should be made. E.g. If we need to
	// insert an element C, and the rule is that the order of children has to be
	// As, Bs, Cs. After will be equal to "C;B;A".
	function findInsertIdx (children, after) {
	const childrenTags = children.map(child => child.tag);
	const afters = after.split(';');
	const afterIndexes = afters.map(current => childrenTags.lastIndexOf(current));
	const foundIndex = _.find(afterIndexes, index => index !== -1);

	// add to the beginning if no matching nodes are found
	return typeof foundIndex === 'undefined' ? 0 : foundIndex + 1;
	}

	const BLACKLIST = ['platform', 'feature', 'plugin', 'engine'];
	const SINGLETONS = ['content', 'author', 'name'];
	function mergeXml (src, dest, platform, clobber) {
	// Do nothing for blacklisted tags.
	if (BLACKLIST.includes(src.tag)) return;

	// Handle attributes
	Object.getOwnPropertyNames(src.attrib).forEach(attribute => {
	if (clobber \|\| !dest.attrib[attribute]) {
	dest.attrib[attribute] = src.attrib[attribute];
	}
	});
	// Handle text
	if (src.text && (clobber \|\| !dest.text)) {
	dest.text = src.text;
	}
	// Handle children
	src.getchildren().forEach(mergeChild);

	// Handle platform
	if (platform) {
	src.findall('platform[@name="' + platform + '"]').forEach(platformElement => {
	platformElement.getchildren().forEach(mergeChild);
	});
	}

	// Handle duplicate preference tags (by name attribute)
	removeDuplicatePreferences(dest);

	function mergeChild (srcChild) {
	const srcTag = srcChild.tag;
	let destChild = new et.Element(srcTag);
	let foundChild;
	const query = srcTag + '';
	let shouldMerge = true;

	if (BLACKLIST.includes(srcTag)) return;

	if (SINGLETONS.includes(srcTag)) {
	foundChild = dest.find(query);
	if (foundChild) {
	destChild = foundChild;
	dest.remove(destChild);
	}
	} else {
	// Check for an exact match and if you find one don't add
	const mergeCandidates = dest.findall(query)
	.filter(foundChild =>
	foundChild && textMatch(srcChild, foundChild) && attribMatch(srcChild, foundChild)
	);

	if (mergeCandidates.length > 0) {
	destChild = mergeCandidates[0];
	dest.remove(destChild);
	shouldMerge = false;
	}
	}

	mergeXml(srcChild, destChild, platform, clobber && shouldMerge);
	dest.append(destChild);
	}

	function removeDuplicatePreferences (xml) {
	// reduce preference tags to a hashtable to remove dupes
	const prefHash = xml.findall('preference[@name][@value]').reduce((previousValue, currentValue) => {
	previousValue[currentValue.attrib.name] = currentValue.attrib.value;
	return previousValue;
	}, {});

	// remove all preferences
	xml.findall('preference[@name][@value]').forEach(pref => {
	xml.remove(pref);
	});

	// write new preferences
	Object.keys(prefHash).forEach(function (key) {
	const element = et.SubElement(xml, 'preference');
	element.set('name', key);
	element.set('value', this[key]);
	}, prefHash);
	}
	}

	// Expose for testing.
	module.exports.mergeXml = mergeXml;

	function textMatch (elm1, elm2) {
	const text1 = elm1.text ? elm1.text.replace(/\s+/, '') : '';
	const text2 = elm2.text ? elm2.text.replace(/\s+/, '') : '';
	return (text1 === '' \|\| text1 === text2);
	}

	function attribMatch (one, two) {
	const oneAttribKeys = Object.keys(one.attrib);
	const twoAttribKeys = Object.keys(two.attrib);

	if (oneAttribKeys.length !== twoAttribKeys.length) {
	return false;
	}

	for (let i = 0; i < oneAttribKeys.length; i++) {
	const attribName = oneAttribKeys[i];

	if (one.attrib[attribName] !== two.attrib[attribName]) {
	return false;
	}
	}

	return true;
	}