iframe Framework and Pros and Cons

HTML5 no longer supports the use of frame. For the difference between frame and iframe, please refer to Difference between iframe and frame.

Basic Usage

  • src: Specifies the URL of the document to be displayed in the iframe.
  • frameborder: Specifies whether to display the border around the frame.
  • scrolling: Specifies whether to display the scrollbars in the iframe.
  • width: Specifies the width of the iframe, it is recommended to use CSS instead.
  • height: Specifies the height of the iframe, it is recommended to use CSS instead.
  • sandbox: Enables a set of additional restrictions on the content within the iframe.
  • marginwidth: Defines the left and right margins of the iframe.
  • marginheight: Defines the top and bottom margins of the iframe.
  • srcdoc: Specifies the HTML content of the page to be displayed in the iframe.
  • align: Specifies how to align the frame relative to the surrounding elements, it is recommended to use styles instead.

Use Cases

Loading web pages from other domains

<iframe> allows cross-domain requests for resources, but cannot be modified. Therefore, it can be used to embed other web pages in a web page. If cross-domain communication is required, consider using document.domain, window.name, window.postMessage.

Typical system structure

In a typical system structure, the left side is the function tree, the top is personal information, and the right side is the actual functionality. Using iframe to separate the functionality, vue and react can also be used for implementation.

Implementing Ajax

iframe can be used to simulate asynchronous request sending and achieve the same effect as Ajax. The completion of an asynchronous Ajax request is triggered when XHR.readyState === 4, while iframe uses iframe.onload to trigger the completion. It can also be used to implement long polling.

Loading advertisements

Advertisements are unrelated to the original content. If hardcoded, it will cause layout disorder and require additional CSS and JS files, greatly reducing the security of the web page. Using iframe can solve these problems.

Submitting forms

iframe can be used to submit forms without refreshing the entire page, and can also achieve file uploads without refreshing.

Pros and Cons

Pros

  1. Can make cross-domain requests to other websites and display the complete website.
  2. The typical system structure improves code reusability.
  3. Creates a new independent hosting environment, allowing isolation or access to native interfaces and objects.
  4. Module separation, if multiple pages reference the same iframe, it is easier to modify.
  5. Provides a solution for displaying advertisements.
  6. If the iframe needs to be refreshed, only the frame needs to be refreshed, not the entire page.

Cons

  1. iframes block page loading and affect web page loading speed. The window.onload event is triggered only after the iframe is loaded. This can be solved by dynamically setting src.
  2. Loading a new page increases the requests for CSS and JS files, adding extra HTTP requests and increasing server load.
  3. Sometimes, due to the space occupied by the iframe, scrollbars appear, causing layout disorder.
  4. Not SEO-friendly, search engine crawlers cannot interpret the content of the iframe pages.
  5. Some small mobile devices such as phones may not fully display the frame, resulting in poor compatibility.
  6. The iframe shares the link pool with the main page. If the link pool is exhausted during iframe loading, it will cause the main page to be blocked.

Daily Question

https://github.com/WindrunnerMax/EveryDay

References

https://www.zhihu.com/question/20653055 https://www.cnblogs.com/hq233/p/9849939.html https://blog.csdn.net/baxiadsy_csdn/article/details/86245809
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