Key Points

• This article discusses the issue of using JavaScript/jQuery to dynamically insert scripts into DOM head tags during page loading. The author provides solutions for the following issues: IE8 error messages caused by encrypting pages/websites; loading a second script that references variables created by the first script resulted in an undefined error message; document.write causes page refresh.
• The author provides a final script that can be run in all browsers, including IE8. This script avoids errors by checking that the page is not encrypted before loading the OpenX script and checking that the variable exists before using it.
• The FAQ section emphasizes the importance of inserting scripts into secure encrypted pages to maintain website security and integrity. It also provides information about jQuery, tips for ensuring scripts are secure, common errors when inserting scripts into secure encrypted pages, and ways to debug and optimize jQuery scripts for performance.

We encountered this time-consuming problem and thought we should share it with people who were in the same situation. Sorry, this post is long, but it's a very tricky puzzle! Problem: Use JavaScript/jQuery to dynamically insert scripts into DOM head tags when page loads. This example shows that we are trying to load an OpenX script on the page. We encountered the following problem: - IE8 error message due to encrypted pages/websites – To do this, we can check the encrypted pages and load OpenX scripts only for unencrypted pages. - Loading the second script that references the variable created by the first script results in an undefined error message - To do this, we simply add an if statement to check if the variable exists and then use it again. - document.write causes page refresh - To do this, do not use document.write after the page is loaded.

(function() {
  if (window.location.protocol !== 'https:') {
    var openx = document.createElement('script');
    openx.type = 'text/javascript';
    openx.async = true;
    openx.src = ''; //此處需填寫腳本路徑

    // 插入到 head 中
    var theHead = document.getElementsByTagName('head')[0];
    theHead.appendChild(openx);

    console.log('腳本已插入 head');
  }
})();

If you want to include multiple lines of js scripts in your head (i.e., more than just a .js file), you can do this.

(function() {
  if (window.location.protocol !== 'https:') {
    /* 創(chuàng)建動態(tài)腳本 */
    var openX = document.createElement('script');
    openX.type = 'text/javascript';
    openX.defer = 'defer'; /* defer 僅受 IE 支持 */
    openX.async = true; /* async 是 html5 建議 */
    openX.src = ''; //此處需填寫腳本路徑
    var multiOpenX = document.createElement('script');
    multiOpenX.type = 'text/javascript';
    multiOpenX.defer = 'defer';
    multiOpenX.async = true;
    multiOpenX.innerHTML = [
      'var OX_4ddf11d681ca9 = OX();',
      'OX_4ddf11d681ca9.addPage("2400");',
      'OX_4ddf11d681ca9.fetchAds();'
    ].join('\n');

    /* 插入到 head 標(biāo)簽 */
    var theHead = document.getElementsByTagName('head')[0];
    theHead.appendChild(openX);
    theHead.appendChild(multiOpenX);
  }
})();

IE8 appears to produce an error when using innerHTML tags in the head section. I can't see a solution to this problem except for an alternative to not using innerHTML. We can restore to jQuery.getScript() and then pass in the second script parameter after the first script is loaded, as shown below:

$.getScript('ajax/test.js', function() {
  alert('加載已完成。');
});

You can even put it in a function and call it from the body as follows:

function LoadMyJs(scriptName) {
  var theHead = document.getElementsByTagName("head")[0];
  var dynamicScript = document.createElement("script");
  dynamicScript.type = "text/javascript";
  dynamicScript.src = scriptName;
  theHead.appendChild(dynamicScript);
}

You can also write multi-line scripts like this (Warning: Some browsers insert line breaks at continuation, while others don't).

var multiOpenX =
  ' \n' +
  '  var OX_4ddf23d681ca9 = OX(); \n' +
  '  OX_4ddf231181ca9.addPage("2400"); \n' +
  '  OX_4ddf231181ca9.fetchAds(); \n' +
  '';

final script

The final script that works fine in all browsers (including IE8):

if (window.location.protocol !== 'https:') {
  /* 加載 OpenX 腳本 */
  document.write(unescape('%3Cscript src="<path script="" to="">" type="text/javascript"%3E%3C/script%3E')); //此處需填寫腳本路徑
}

if (typeof OX === 'function') {
  var OX_4ddf23d681119 = OX();
  OX_4ddf23d681119.addPage("2400");
  OX_4ddf23d681119.fetchAds();
}</path>

Please also view the references for different checks in the URL here: http://www.miracleart.cn/link/0db1abb0147975f10b47eba2f817e01d

FAQs on Inserting Scripts into Secure Encryption Page

What is the importance of inserting scripts into secure encrypted pages?

Inserting scripts into secure encrypted pages is essential to maintaining the security and integrity of your website. Scripts (particularly those written by jQuery) can manipulate HTML content, process events, create animations, and perform many other features that enhance the user experience. However, if these scripts are not inserted into secure encrypted pages, hackers can use them to inject malicious code, steal sensitive data, or destroy the functionality of the website. Therefore, it is necessary to make sure that the script is inserted into a secure encrypted page to protect your website and its users.

How to ensure my script is safe?

Ensure scripts are safe involves multiple steps. First, always use HTTPS (Hypertext Transfer Protocol Security) for your website. This encrypts the data transmitted between the user's browser and your website, preventing it from being blocked. Second, verify all user input to prevent script injection attacks. This includes checking whether the input is of the expected type and format before processing it. Third, use the Content Security Policy (CSP) header to limit which scripts can run on your website. This prevents unauthorized scripts from being executed.

What is jQuery and why use it?

jQuery is a fast, compact and feature-rich JavaScript library. It makes it easier to use an easy-to-use API (which can be run on multiple browsers). With its versatility and scalability, jQuery has changed the way millions of people write JavaScript.

How to encrypt my jQuery script?

The jQuery scripts can be encrypted using a variety of methods. A common approach is to use a JavaScript obfuscator, which converts your code into an equivalent but more difficult to understand format. This can prevent hackers from trying to reverse engineer your code. However, it should be noted that this does not provide absolute security, as experienced hackers can still work hard enough to antiobfuscate the code. Therefore, other security best practices must also be followed, such as using HTTPS and verifying user input.

How does jQuery work?

jQuery works by providing a simple and consistent interface to interact with HTML documents. It abstracts the complexity of many JavaScript, allowing you to write less code to get the same results. For example, you can use jQuery to select elements, process events, create animations, and execute AJAX requests in just a few lines of code. jQuery also deals with many of the cross-browser compatibility issues that can arise when writing JavaScript, making your code stronger and more reliable.

Can I encrypt and decrypt data using jQuery?

Yes, you can use jQuery in conjunction with encryption libraries such as CryptoJS to encrypt and decrypt data. This is very useful for protecting sensitive data such as passwords or credit card numbers. However, it is important to note that client encryption should not be the only security measure you use. It should be combined with server-side encryption and other security practices, such as using HTTPS and verifying user input.

How to learn more about jQuery?

There are many resources available for learning jQuery. The official jQuery website provides comprehensive documentation, tutorials and examples. Many online courses, books and tutorials are also available from various sources. Additionally, sites like StackOverflow and jQuery forums are great places to ask questions and learn from other developers.

What are some common mistakes when inserting scripts into secure encrypted pages?

Some common mistakes when inserting scripts into secure encrypted pages include not using HTTPS, not verifying user input, and not using content security policy headers. These errors can make your website vulnerable to script injection attacks, and hackers can insert malicious code into your scripts. Another common mistake is relying solely on client encryption to ensure security. While client encryption can provide an additional layer of protection, it should be combined with server-side encryption and other security practices.

How to debug my jQuery script?

JQuery scripts can be debugged using developer tools in a web browser. These tools allow you to check the website's HTML, CSS, and JavaScript, set breakpoints, step through code, and view any errors or warnings. There are also some jQuery plugins that can be used to help debug, such as jQuery Debugger and FireQuery.

How to optimize my jQuery scripts for performance?

Optimizing jQuery scripts to improve performance may involve multiple strategies. First, try to minimize the number of DOM operations, as these operations can be costly in terms of performance. Second, use event delegates to handle events of multiple elements using a single event handler. Third, use the .ready() method to make sure your script runs only after the DOM is fully loaded. Finally, consider using a minifier to reduce the size of the script, which can improve loading time.

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