which will render first <apex:includeScript> or <script> tag and what is the difference between them? How to use JS fucntion in Visualforce?

Question

I was roaming around the internet for this question.

I want to use include jquery first then mu custom js which uses jquery.

After the above steps, I want to call a function from my custom js which will take my json data's value returned by apex. ie. customeJSFunction(jsonValueArg)

Thanks.

Answer 1

You can use loadOnReady attribute on apex:includeScript - meaning, that library will load only after DOM is constructed. For script you dont have such capability.

Also apex:includeScript docs:

Multiple references to the same script are de-duplicated, making this component safe to use inside an iteration component. This might occur if, for example, you use an inside a custom component, and then use that component inside an iteration.

Interesting read on script tag:

• If async is present: The script is executed asynchronously with the rest of the page (the script will be executed while the page continues the parsing)
• If async is not present and defer is present: The script is executed when the page has finished parsing
• If neither async or defer is present: The script is fetched and executed immediately, before the browser continues parsing the page