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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
/**
* Helper functions for parsing and serializing XML
*/
// NOTE: This module should not be loaded directly, it is available when
// including calUtils.sys.mjs under the cal.xml namespace.
export var xml = {
/**
* Evaluate an XPath query for the given node. Be careful with the return value
* here, as it may be:
*
* - null, if there are no results
* - a number, string or boolean value
* - an array of strings or DOM elements
*
* @param {Node|Document} aNode The context node to search from
* @param aExpr The XPath expression to search for
* @param aResolver (optional) The namespace resolver to use for the expression
* @param aType (optional) Force a result type, must be an XPathResult constant
* @returns The result, see above for details.
*/
evalXPath(aNode, aExpr, aResolver, aType) {
/** @type Document */
const doc = aNode.ownerDocument ? aNode.ownerDocument : aNode;
const resolver = aResolver || doc.createNSResolver(doc.documentElement);
const resultType = aType || XPathResult.ANY_TYPE;
const result = doc.evaluate(aExpr, aNode, resolver, resultType, null);
let returnResult, next;
switch (result.resultType) {
case XPathResult.NUMBER_TYPE:
returnResult = result.numberValue;
break;
case XPathResult.STRING_TYPE:
returnResult = result.stringValue;
break;
case XPathResult.BOOLEAN_TYPE:
returnResult = result.booleanValue;
break;
case XPathResult.UNORDERED_NODE_ITERATOR_TYPE:
case XPathResult.ORDERED_NODE_ITERATOR_TYPE:
returnResult = [];
while ((next = result.iterateNext())) {
if (next.nodeType == next.TEXT_NODE || next.nodeType == next.CDATA_SECTION_NODE) {
returnResult.push(next.wholeText);
} else if (ChromeUtils.getClassName(next) === "Attr") {
returnResult.push(next.value);
} else {
returnResult.push(next);
}
}
break;
case XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE:
case XPathResult.ORDERED_NODE_SNAPSHOT_TYPE:
returnResult = [];
for (let i = 0; i < result.snapshotLength; i++) {
next = result.snapshotItem(i);
if (next.nodeType == next.TEXT_NODE || next.nodeType == next.CDATA_SECTION_NODE) {
returnResult.push(next.wholeText);
} else if (ChromeUtils.getClassName(next) === "Attr") {
returnResult.push(next.value);
} else {
returnResult.push(next);
}
}
break;
case XPathResult.ANY_UNORDERED_NODE_TYPE:
case XPathResult.FIRST_ORDERED_NODE_TYPE:
returnResult = result.singleNodeValue;
break;
default:
returnResult = null;
break;
}
if (Array.isArray(returnResult) && returnResult.length == 0) {
returnResult = null;
}
return returnResult;
},
/**
* Convenience function to evaluate an XPath expression and return null or the
* first result. Helpful if you just expect one value in a text() expression,
* but its possible that there will be more than one. The result may be:
*
* - null, if there are no results
* - A string, number, boolean or DOM Element value
*
* @param aNode The context node to search from
* @param aExpr The XPath expression to search for
* @param aResolver (optional) The namespace resolver to use for the expression
* @param aType (optional) Force a result type, must be an XPathResult constant
* @returns The result, see above for details.
*/
evalXPathFirst(aNode, aExpr, aResolver, aType) {
const result = xml.evalXPath(aNode, aExpr, aResolver, aType);
if (Array.isArray(result)) {
return result[0];
}
return result;
},
/**
* Parse the given string into a DOM tree
*
* @param str The string to parse
* @returns The parsed DOM Document
*/
parseString(str) {
const parser = new DOMParser();
parser.forceEnableXULXBL();
return parser.parseFromString(str, "application/xml");
},
/**
* Read an XML file synchronously. This method should be avoided, consider
* rewriting the caller to be asynchronous.
*
* @param uri The URI to read.
* @returns The DOM Document resulting from the file.
*/
parseFile(uri) {
const req = new XMLHttpRequest();
req.open("GET", uri, false);
req.overrideMimeType("text/xml");
req.send(null);
return req.responseXML;
},
/**
* Serialize the DOM tree into a string.
*
* @param doc The DOM document to serialize
* @returns The DOM document as a string.
*/
serializeDOM(doc) {
const serializer = new XMLSerializer();
return serializer.serializeToString(doc);
},
/**
* Escape a string for use in XML
*
* @param str The string to escape
* @param isAttribute If true, " and ' are also escaped
* @returns The escaped string
*/
escapeString(str, isAttribute) {
return str.replace(/[&<>'"]/g, chr => {
switch (chr) {
case "&":
return "&";
case "<":
return "<";
case ">":
return ">";
case '"':
return isAttribute ? """ : chr;
case "'":
return isAttribute ? "'" : chr;
default:
return chr;
}
});
},
};