如何在 html 的输入字段中突出显示新文本

Question

Within Servicenow portals I am trying to create a input text field that has a few requirements when the user tries to make changes to the text. Within the form if the user wants to change the text that has already been added the new input text will have to be highlighted. Only the new changes can be highlighted. The previous text will stay the same without any highlights. I have looked into the html tag but that highlights the entire text field and also tried using a 'focus' within the css tag name.

HTML:

<input type="text" value={{data.text2}}>

CSS: input:focus::first-line { background-color: #fff2ac; }

Answer 1

You could use Javascript to position a dynamically generated span with the highlighting, on top of the input... and then update that span's text whenever the underlying input changes.

See the last option in the top answer here for more details: How to highlight text inside an input field? .

It even mentions a jQuery plug-in with this effect that you could use, or examine the source of: https://github.com/garysieling/jquery-highlighttextarea .