Can a `` tag have both `src` and content, and how reliably does that work across browsers?

Understanding the Script Tag with Both src and Content

In HTML, the script tag is commonly used to load and execute JavaScript code. Typically, the src attribute is employed to specify the URL of an external JavaScript file. However, in certain cases, a script tag may also include content within the opening and closing tags.

Example from Google's 1 Button:

Consider the following code from Google's 1 button:

<script type="text/javascript" src="https://apis.google.com/js/plusone.js">
  {"parsetags": "explicit"}
</script>

In this example, the script tag has both a src attribute, pointing to an external JavaScript file, and content within the tags.

Browser Behavior and Reliability:

Different browsers handle this scenario in different ways. Some browsers execute the content if the src attribute is successfully included without error. Others attempt to include the src script and execute the content regardless of success.

Unpredictable Behavior and Deprecation in HTML5:

However, this behavior is highly unpredictable and unreliable. In HTML5, the use of both src and content in a script tag is prohibited. This is because the browser's behavior can vary widely, leading to potential compatibility issues.

Google's Approach:

Google's approach in the above example is not dependent on any specific browser behavior. The content within the script tag is an object literal, which is a static value. When the browser executes it, no significant action is performed aside from a silent error. Instead, Google's code analyzes the contents of the script tag itself and adjusts its behavior accordingly.

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