How to convert string to xml format in javascript

JavaScript is a scripting language widely used in front-end web page development. In web development, we usually need to send data to the server in XML format, or receive XML data from the server and parse it. In such cases, it is very important to convert the JavaScript string to XML format.

In this article, we will take an in-depth look at how to convert a string into XML format using JavaScript. This will help web developers write more efficient XML code and process web application data quickly.

First step, understand the XML format

Before converting strings to XML, we need to understand what XML is and its basic structure. XML is Extensible Markup Language (XML), used to describe the structure and content of data. XML can be used for data transmission and data storage, and can also be used to describe application configuration information.

XML consists of markup and text. Tags are XML elements used to describe data. Text and other tags can be included between tags. Each XML element consists of a start tag and an end tag. The start tag contains the element name and attributes, and the end tag only contains the element name. The following is an example of an XML element:

<book id="1234">
  <title>JavaScript 字符串转换XML</title>
  <author>John Doe</author>
  <price>29.99</price>
</book>

In the above example, we can see that the <book> element is an XML element that contains text and other markup. It also has an attribute named "id" which has the value "1234". In the closing tag, we only see the tag name and nothing else.

Second step, use JavaScript to create an XML string

With an understanding of XML, now we can start converting the string into XML format. In JavaScript, we can use string manipulation and DOM manipulation to create XML strings.

We can use string concatenation to create XML strings, for example:

let xmlStr = '<book id="1234">';
xmlStr += '<title>JavaScript 字符串转换XML</title>';
xmlStr += '<author>John Doe</author>';
xmlStr += '<price>29.99</price>';
xmlStr += '</book>';

In the above example, we use the plus sign to concatenate multiple strings and save them to variables xmlStr in. After all the necessary XML elements and attributes are added, we add the </book> tag as the closing tag.

DOM manipulation is also a way to create XML strings. We can use the JavaScript DOM API to create XML nodes and build XML structures by adding nodes to the DOM tree. For example, in the following code snippet, we create an XML element and add it to the XML document:

let xmlDoc = document.implementation.createDocument("", "", null);
let bookElem = xmlDoc.createElement("book");
let titleElem = xmlDoc.createElement("title");
let titleText = xmlDoc.createTextNode("JavaScript 字符串转换 XML");
titleElem.appendChild(titleText);
bookElem.appendChild(titleElem);
xmlDoc.appendChild(bookElem);

In the above code snippet, we first use the createDocument() method Create an XML document object, and then use the createElement() method to create an XML element named "book". Next, we create another element called "title" within the XML element and add text to that element by using the createTextNode() method. Finally, we add the "title" element to the XML document object.

The third step is to parse the string into XML

When sending XML data to the server or receiving XML data from the server, we need to convert the string into an XML object for easy parsing. and operations. In JavaScript, we can use the DOMParser object to parse a string into an XML document.

For example, in the following code snippet, we parse a string named xmlStr into an XML document:

let xmlDoc;
if (window.DOMParser) {
  let parser = new DOMParser();
  xmlDoc = parser.parseFromString(xmlStr, "text/xml");
} else {
  xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
  xmlDoc.loadXML(xmlStr);
}

In the above code snippet, we first Check if the browser supports DOMParser object. If supported, the xmlStr string is parsed into an XML document using the parseFromString() method. Otherwise, we use ActiveXObject objects (only available in Internet Explorer browsers) to parse the XML string.

The fourth step, XML data parsing

Once we parse the XML string into an XML document object, we can start parsing and manipulating the XML data. In JavaScript, we can use the getElementsByTagName() method to access XML elements, and the getAttribute() method to access the attributes of XML elements. For example, in the following code snippet, we use the XML document object to get the <book> element:

let bookElem = xmlDoc.getElementsByTagName("book");

We can then get the # using the getAttribute() method ##<book>The value of the "id" attribute of the element:

let bookId = bookElem[0].getAttribute("id");

In the above code snippet, we first access the XML

<book> element and put They are saved to the variable bookElem. We then get the "id" attribute of the first instance of the bookElem element and save it into the variable bookId.

Conclusion

Converting string to XML format is a very basic task in web development. In this article, we learned how to convert strings to XML format using JavaScript and learned about the basic structure and basic operations of XML. This will help web developers process XML data more efficiently and support the development of web applications. Finally, let us advocate the adoption of modern web standards and the use of jQuery, React, Vue.js and other JavaScript frameworks to better solve problems encountered in web development.

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