Javascript select a sentence in textarea
I'm thinking if there is a way to use javascript to pick up ANY ONE sentence from a textarea simply by clicking any position within that sentence.
I'm thinking along the line of - first, get curren开发者_如何学Ct cursor position (which I know how) - second, somehow locate the position of the previous fullstop and the next fullstop (how?) - take whatever content within the two fullstops. (how?)
Or there is a simple way to do it?
I assume you already know about handling caret position and getting the content before / after the caret, so here's a pseudocode solution:
- User clicks on textarea
- Get current caret position
- Store everything before caret position in variable A
- Store everything after caret position in variable B
- Find position of last full stop in A using lastIndexOf()
- Find position of first full stop in B using indexOf()
- Handle situations where full stop is not found
- set position to 0 in case of A
- end of string in case of B)
- Take substring (last_pos, end_pos) from A
- Take substring (0, first_pos) from B
- Combine substrings.
I started working on this before other people responded because I was so intrigued by it. Here is what I got to work. You can probably base your work off this and incorporate the other suggestions:
<html>
<script type="text/javascript">
function getsentence(){
var ta = document.getElementById("ta");
var cursor = ta.selectionStart;
var text = ta.value;
//Find the beginning
var start;
for(var i = cursor; i > 0; i--){
if(text.charAt(i) === "."){
start = i+2;
break;
}
start = 0;
}
//Find end
var end;
for(var i = cursor; i < text.length; i++){
if(text.charAt(i) === "."){
end = i+1;
break;
}
end = text.length;
}
alert(text.substring(start, end));
}
</script>
<body>
<textarea id="ta" rows="10" cols="50" onclick="getsentence()">
This is a sample. Here is sentence two. Here is sentence three. And now on to number four.
</textarea>
</body>
</html>
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