[whatwg] Request for new DOM property textarea.selectionText

Ryosuke Niwa rniwa at webkit.org
Fri Apr 27 21:11:42 PDT 2012


Why are we adding this new API? WebKit already supports

document.execCommand('InsertText', false, "new selected text");

- Ryosuke

On Fri, Apr 27, 2012 at 9:01 PM, Ian Hickson <ian at hixie.ch> wrote:

> On Mon, 10 May 2010, Biju wrote:
> >
> > Can we have a new DOM property textarea.selectionText which can be used
> > to set/get selection text of a TEXTAREA/INPUT type=text.
>
> Gettng the value is relatively easy:
>
> On Mon, 10 May 2010, Biju wrote:
> >
> > Current way in firefox is to
> >
> > 1. OrigStart = textarea.selectionStart
>
> But admittedly setting it is a pain:
>
> > 2.  textarea.value = textarea.value.substr(0, OrigStart)
> >                           + new_text_to_replace
> >                           + textarea.value.substr(textarea.selectionEnd);
> > 3. Now u loose original selection, so
> >
> > 4.  textarea.setSelectionRange(OrigStart,
>  OrigStart+new_text_to_replace.length)
> > 5.  remember .scrollTop and reapply if needed
>
> I agree that making this easier would be good.
>
>
> > On IE even though wierd you can do it simply by
> >    document.selection.createRange().text = new_text_to_replace;
> > BTW, you need to make sure the selection is currently on the
> > textarea/input form control.
> > IE is also very fast when doing that, when firefox hangs few second
> > using the other way
>
> IE's version is non-standard and not adopted by other UAs.
>
>
> On Mon, 10 May 2010, Ojan Vafai wrote:
> >
> > In addition to selection and scroll issues, needing to replace the
> > entire textarea value doesn't scale and thus limits what sorts of things
> > you can do with textareas. A general way to set a sub-part of a
> > textarea's value seems useful to me. I don't think we should tie that to
> > setting the selected text though.
> >
> > textarea.setRangeText(start, end, text);
> >
> > It replaces the text between start and end, maintains current scroll
> > position and preserves the selection.
>
> On Tue, 11 May 2010, Biju wrote:
> >
> > Both have advantages
> >
> > Option 1 (textobj.selectionText) advantages
> > * No need for web developer to provide selection start/end
> > * Automatically select the newly inserted text,
> >    (as most time that is what you want)
> > * No need for web developer to calculate selection start/end for
> > setting it after text insert
> > * preserve scroll
> > * Has both Getter and Setter
> >
> > Option 2 (textobj.setRangeText(start, end, text)); advantages
> > * Independent of selection, web developer can change text at any range
> >    with out affecting selection
> > * Web developer has more options with it.
> > * preserve scroll
> >
> > So I want to merge both suggestion, with a new signature,
> > also trying to reduce coding for web developer "less code less bug"
> >
> > textobj.setRangeText(newtext, start, end, cursorpos)
> >
> > parameters:
> > newtext
> >  - optional parameter
> >  - new text that will replace existing
> >  - if missing/null/undefined/NaN then default to ""
> >
> > start
> >  - optional parameter
> >  - starting position of the original textobj text that need to be
> replaced
> >  - if missing/null/undefined/NaN then default to textobj.selectionStart
> >  - negative value make start position from last character in the text
> content
> >
> > end
> >  - optional parameter
> >  - ending position of the original textobj text that need to be replaced
> >  - if missing/null/undefined/NaN then default to textobj.selectionEnd
> >  - negative value make end position from last character
> >
> > cursorpos
> >  - optional parameter
> >  - if missing/null/undefined/NaN then default to 0
> >  - what should happen to cursor/selection after text insert, its values
> are
> >  - - 0 - select the newly inserted text
> >  - - 1 - place cursor at beginning of inserted text
> >  - - 2 - place cursor at the end of inserted text
> >  - - 3 - keep selection unaffected
> > * issue, when value is 3 what should we do when setRangeText is
> replacing text
> > which has some parts selected and some other parts unselected
> >
> >
> > so if somebody want replace selection text it is just
> >      textobj.setRangeText(newtext);
> > which is almost same as my original proposal, and
> >      textobj.setRangeText();
> > will blank a selection
>
> That seems a bit overly complicated, but something in that vein seems
> reasonable.
>
> I've added
>
>   setRangeText(newText); // replace selection with newText
>   setRangeText(newText, start, end); // replace given range with newText
>   setRangeText(newText, start, end, action); // see below
>
> ...where action is one of:
>
>   'select': selects the new text
>   'start': selects empty range at start of new text
>   'end': selects empty range at end of new text
>   'preserve': (default) set selection as follows:
>
>    - if selection start was before range, leave as is
>    - if selection start was after the old range, put it as far from the
>      end of the new range as it was from the end of the old range
>    - if selection start was in the old range, move it to the start of the
>      new range
>
>    - if selection end was before range, leave as is
>    - if selection end was after the old range, put it as far from the
>      end of the new range as it was from the end of the old range
>    - if selection emd was in the old range, move it to the end of the
>      new range
>
>
> > We could also add a getter method, also with optional parameters
> >      textobj.getRangeText(start, end)
> > so,
> > textobj.getRangeText() gives current selection
> > textobj.getRangeText(0) gives from start of text to current selection end
> > textobj.getRangeText(null, -1) gives from current selection start to end
> of text
>
> Getting the text from a range is already rather simple (as demonstrated at
> the top of this e-mail), so I don't think that's necessary.
>
> --
> Ian Hickson               U+1047E                )\._.,--....,'``.    fL
> http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
> Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
>


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