determine the frame id/name when a user has select

问题:

I have a scenario in which there are multiple iframes/frames open in one web page. Now user may select some text in any one of the open frames/iframes. I want to determine the id/name of the iframe in which user has selected text, using the iframe id/name I will then do some operations on the selected text.

How do I do this?

回答1:

This will get the first iframe in the curent document that has a non-empty selection. If an iframe is from another domain and hence inaccessible to JavaScript running in the current document, the selection cannot be retrieved and the iframe is ignored.

function getSelectedText(win) {
    var sel;
    if (win.getSelection) {
        return "" + win.getSelection();
    } else if ( (sel = win.document.selection) ) {
        if (sel.type == "Text") {
            return sel.createRange().text;
        }
    }
    return "";
}

function getIframeWithSelection(win) {
    var iframes = win.document.getElementsByTagName("iframe");
    for (var i = 0, len = iframes.length, selectedText; i < len; ++i) {
        try {
            selectedText = getSelectedText(iframes[i].contentWindow);
            if (selectedText != "") {
                // alert just there for debugging
                alert(selectedText);
                return iframes[i];
            }
        } catch (e) {}
    }
    return null;
}

// Example
var iframe = getIframeWithSelection(window);