So I feel like I'm a bit out of my league here. But here's what I want to do.
Basically, I want to have a user select part of text within in a paragraph (which may contain many elemnts (i.e. <span> and <a>) to return the value of the id attribute of that paragraph. Here's what I thinking.
function getParaID() //function will be called using a mouseUp event
{
var selObj = window.getSelection();
var selRange = selObj.getRangeAt(0); //btw can anyone explain what this zero means
var paraElement = selRange.commonAncestorContainer;
var paraID = paraElement.getAttribute;
return paraID;
}
What do you think? Am I close?
The selection range's commonAncestorContainer property may be a reference to a text node, or a <span> or <a> element or <body> element, or whatever else you may have in your page. That being the case, you need to work up the DOM tree to find the containing <p> element, if one exists. You also need to be aware that IE < 9 does not support window.getSelection() or DOM Range, although it is possible to do what you want quite easily in IE < 9. Here's some code that will work in all major browsers, including IE 6:
jsFiddle: http://jsfiddle.net/44Juf/
Code:
function getContainingP(node) {
while (node) {
if (node.nodeType == 1 && node.tagName.toLowerCase() == "p") {
return node;
}
node = node.parentNode;
}
}
function getParaID() {
var p;
if (window.getSelection) {
var selObj = window.getSelection();
if (selObj.rangeCount > 0) {
var selRange = selObj.getRangeAt(0);
p = getContainingP(selRange.commonAncestorContainer);
}
} else if (document.selection && document.selection.type != "Control") {
p = getContainingP(document.selection.createRange().parentElement());
}
return p ? p.id : null;
}
Regarding the 0 passed to getRangeAt(), that is indicating which selected range you want. Firefox supports multiple selected ranges: if you make a selection and then hold down Ctrl and make another selection, you will see you now have two discontinous ranges selected, which can be accessed via getRangeAt(0) and getRangeAt(1). Also in Firefox, selecting a column of cells in a table creates a separate range for each selected cell. The number of selected ranges can be obtained using the rangeCount property of the selection. No other major browser supports multiple selected ranges.
You're quite close. If all you want is the id of the parent element, then you should replace your paraElement.getAttribute with paraElement.id, like:
var paraID = paraElement.id;
Regarding the parameter to getRangeAt(), it is specifying the index of the selection range to return, and it's only really relevant to controls that allow discontinuous selections. For instance, a select box in which the user can use ctrl + click to select several arbitrary groups of rows simultaneously. In such a case you could use the parameter to step from one selected region to the next. But for highlighting text within a paragraph you should never have a discontinuous selection and thus can always pass 0. In essence it means that you're asking for "the first selected region".
Also note that if your interface allows the user's selection to span multiple paragraphs then your commonAncestorContainer may not be a paragraph, it might also be whatever element it is that contains all of your paragraph tags. So you should be prepared to handle that case.
Edit:
After playing with this a bit, here is my suggestion: http://jsfiddle.net/vCsZH/
Basically, instead of relying on commonAncestorContainer this code applies a mouseDown and a mouseUp listener to each paragraph (in addition to the one already applied to the top-level container). The listeners will, in essence, record the paragraphs that the selection range starts and ends at, making it much simpler to reliably work out which paragraph(s) are selected.
If ever there was a case in favor of using dynamic event binding through a framework like jQuery, this is it.
Related
I am trying to create my own custom HTML elements where a user can interact with the text within that element. For Example, I created an element where anything between those tags will have a pointer as a mouse cursor and when double clicked, something happens. EG:
<objdc>Double click me!</objdc>
However, this is my code and it is not working:
$(document).ready(function() {
var ObjDblClk = $('objdc');
ObjDblClk.css({ cursor: 'pointer' });
ObjDblClk.dblclick(function(e) {
var range = window.getSelection() || document.getSelection() || document.selection.createRange();
var word = $.trim(range.toString());
if(word != '') {
//Do Something
}
range.collapse();
e.stopPropagation();
});
});
}
Any suggestions?
The problem you have is related with the fact you are not using the collapse method right. It expects a node as parameter and an offset.
So... to fix that exact behavior you posted you would need to do something like:
ObjDblClk.dblclick(function(e) {
var range = window.getSelection() || document.getSelection() || document.selection.createRange();
var word = $.trim(range.toString());
if(word != '') {
//Do Something
}
range.collapse(ObjDblClk[0], 0);
e.stopPropagation();
});
BUT (and this is important): That will do absolutely nothing for your custom selection (especially since is on double click witch affects selection). So you can just remove that line completely and try another solution.
Also: You should read the comments. The guys are right. Unless you are working on some reall strange inhouse thing there may be better aproaches.
Fiddle here (added an alert so you see the function is called - don't forget to select something before double clicking): https://jsfiddle.net/713ndkm0/1/
To create a custom tag like that, you have to be aware of certain things:
Not all browsers will understand your custom tag as a DOM object. IE is a notable example.
Your new custom tag should have a hyphen in it, like obj-dc (more info).
If you want to use it in IE, you have to declare it up-front, as:
document.createElement('obj-dc');
Here is a link to creating new HTML tags for Chrome, in the new way, and here is a link for the older API. As you can see, even the same browser cannot operate with custom tags consistently.
I am using a mouseup event to trigger a function which highlights text and surrounds the highlighted text with a span (function from stack overflow):
function highlightText(e) {
var t = window.getSelection().toString();
if (t) {
$("#mySpan").remove();
var range = window.getSelection().getRangeAt(0);
newNode = document.createElement("span");
newNode.id = 'mySpan';
range.surroundContents(newNode);
}
}
The main problem I am encountering is that as long as surroundContents is included, the text remains highlighted only about 20% of the highlight attempts (otherwise highlighting disappears immediately). I tried adding a setTimeout, not calling surroundContent for 1s. I also tried removing the remove() statement, but still no good.
Any ideas on why this is happening?
I was facing the same problem with Chromium on Android. In some specific cases, the call of range.surroundContents(newNode) would cause a very weird behaviour of page reload and so on. After checking the documentation of the function:
This method is nearly equivalent to
newNode.appendChild(range.extractContents());
range.insertNode(newNode). After surrounding, the boundary points of
the range include newNode.
So the obvious thing was to apply another way highlight the text. I found mark.js library which did exactly what I wanted without that annoying side effect. (Here's a JSFiddle sample that shows how it's used to highlight just selection). The difference is that library was not using range.surroundContents(newNode) nor newNode.appendChild but rather node.replaceChild.
Based on that, here's the solution to the problem I was having and I think it applies to your case as well.
function surroundRangeWithSpan(range) {
var span = document.createElement('span');
// The text is within the same node (no other html elements inside of it)
if (range.startContainer.isEqualNode(range.endContainer) && range.startContainer.childNodes.length == 0) {
// Here you customise your <span> element
customSurroundContents(range, span);
} else {
// Here you have to break the selection down
}
return span;
}
function customSurroundContents(range, span) {
var node = range.commonAncestorContainer;
var startNode = node.splitText(range.startOffset);
var ret = startNode.splitText(range.toString().length);
span.textContent = startNode.textContent;
startNode.parentNode.replaceChild(span, startNode);
}
And you pass window.getSelection().getRangeAt(0) to the function.
The likely cause of the failure is the selected text encompasses only the beginning or the ending of a non-text node, and not both of them.
So if were to run that code only selecting "This is Bo" in the following it will fail (and throw an exception) because it doesn't also capture the closing tag in the selection:
This is <em>bold</em>
So ending up with:
This is <em>bo
Reference: https://developer.mozilla.org/en-US/docs/Web/API/Range/surroundContents
I have a contenteditable div as follow (| = cursor position):
<div id="mydiv" contenteditable="true">lorem ipsum <spanclass="highlight">indol|or sit</span> amet consectetur <span class='tag'>adipiscing</span> elit</div>
I would like to get the current cursor position including html tags. My code :
var offset = document.getSelection().focusOffset;
Offset is returning 5 (full text from the last tag) but i need it to handle html tags. The expected return value is 40. The code has to work with all recents browsers.
(i also checked this : window.getSelection() offset with HTML tags? but it doesn't answer my question).
Any ideas ?
Another way to do it is by adding a temporary marker in the DOM and calculating the offset from this marker. The algorithm looks for the HTML serialization of the marker (its outerHTML) within the inner serialization (the innerHTML) of the div of interest. Repeated text is not a problem with this solution.
For this to work, the marker's serialization must be unique within its div. You cannot control what users type into a field but you can control what you put into the DOM so this should not be difficult to achieve. In my example, the marker is made unique statically: by choosing a class name unlikely to cause a clash ahead of time. It would also be possible to do it dynamically, by checking the DOM and changing the class until it is unique.
I have a fiddle for it (derived from Alvaro Montoro's own fiddle). The main part is:
function getOffset() {
if ($("." + unique).length)
throw new Error("marker present in document; or the unique class is not unique");
// We could also use rangy.getSelection() but there's no reason here to do this.
var sel = document.getSelection();
if (!sel.rangeCount)
return; // No ranges.
if (!sel.isCollapsed)
return; // We work only with collapsed selections.
if (sel.rangeCount > 1)
throw new Error("can't handle multiple ranges");
var range = sel.getRangeAt(0);
var saved = rangy.serializeSelection();
// See comment below.
$mydiv[0].normalize();
range.insertNode($marker[0]);
var offset = $mydiv.html().indexOf($marker[0].outerHTML);
$marker.remove();
// Normalizing before and after ensures that the DOM is in the same shape before
// and after the insertion and removal of the marker.
$mydiv[0].normalize();
rangy.deserializeSelection(saved);
return offset;
}
As you can see, the code has to compensate for the addition and removal of the marker into the DOM because this causes the current selection to get lost:
Rangy is used to save the selection and restore it afterwards. Note that the save and restore could be done with something lighter than Rangy but I did not want to load the answer with minutia. If you decide to use Rangy for this task, please read the documentation because it is possible to optimize the serialization and deserialization.
For Rangy to work, the DOM must be in exactly the same state before and after the save. This is why normalize() is called before we add the marker and after we remove it. What this does is merge immediately adjacent text nodes into a single text node. The issue is that adding a marker to the DOM can cause a text node to be broken into two new text nodes. This causes the selection to be lost and, if not undone with a normalization, would cause Rangy to be unable to restore the selection. Again, something lighter than calling normalize could do the trick but I did not want to load the answer with minutia.
EDIT: This is an old answer that doesn't work for OP's requirement of having nodes with the same text. But it's cleaner and lighter if you don't have that requirement.
Here is one option that you can use and that works in all major browsers:
Get the offset of the caret within its node (document.getSelection().anchorOffset)
Get the text of the node in which the caret is located (document.getSelection().anchorNode.data)
Get the offset of that text within #mydiv by using indexOf()
Add the values obtained in 1 and 3, to get the offset of the caret within the div.
The code would look like this for your particular case:
var offset = document.getSelection().anchorOffset;
var text = document.getSelection().anchorNode.data;
var textOffset = $("#mydiv").html().indexOf( text );
offsetCaret = textOffset + offset;
You can see a working demo on this JSFiddle (view the console to see the results).
And a more generic version of the function (that allows to pass the div as a parameter, so it can be used with different contenteditable) on this other JSFiddle:
function getCaretHTMLOffset(obj) {
var offset = document.getSelection().anchorOffset;
var text = document.getSelection().anchorNode.data;
var textOffset = obj.innerHTML.indexOf( text );
return textOffset + offset;
}
About this answer
It will work in all recent browsers as requested (tested on Chrome 42, Firefox 37, and Explorer 11).
It is short and light, and doesn't require any external library (not even jQuery)
Issue: If you have different nodes with the same text, it may return the offset of the first occurrence instead of the real position of the caret.
NOTE: This solution works even in nodes with repeated text, but it detects html entities (e.g.: ) as only one character.
I came up with a completely different solution based on processing the nodes. It is not as clean as the old answer (see other answer), but it works fine even when there are nodes with the same text (OP's requirement).
This is a description of how it works:
Create a stack with all the parent elements of the node in which the caret is located.
While the stack is not empty, traverse the nodes of the containing element (initially the content editable div).
If the node is not the same one at the top of the stack, add its size to the offset.
If the node is the same as the one at the top of the stack: pop it from the stack, go to step 2.
The code is like this:
function getCaretOffset(contentEditableDiv) {
// read the node in which the caret is and store it in a stack
var aux = document.getSelection().anchorNode;
var stack = [ aux ];
// add the parents to the stack until we get to the content editable div
while ($(aux).parent()[0] != contentEditableDiv) { aux = $(aux).parent()[0]; stack.push(aux); }
// traverse the contents of the editable div until we reach the one with the caret
var offset = 0;
var currObj = contentEditableDiv;
var children = $(currObj).contents();
while (stack.length) {
// add the lengths of the previous "siblings" to the offset
for (var x = 0; x < children.length; x++) {
if (children[x] == stack[stack.length-1]) {
// if the node is not a text node, then add the size of the opening tag
if (children[x].nodeType != 3) { offset += $(children[x])[0].outerHTML.indexOf(">") + 1; }
break;
} else {
if (children[x].nodeType == 3) {
// if it's a text node, add it's size to the offset
offset += children[x].length;
} else {
// if it's a tag node, add it's size + the size of the tags
offset += $(children[x])[0].outerHTML.length;
}
}
}
// move to a more inner container
currObj = stack.pop();
children = $(currObj).contents();
}
// finally add the offset within the last node
offset += document.getSelection().anchorOffset;
return offset;
}
You can see a working demo on this JSFiddle.
About this answer:
It works in all major browsers.
It is light and doesn't require external libraries (apart from jQuery)
It has an issue: html entities like are counted as one character only.
I have a contenteditable div as follow (| = cursor position):
<div id="mydiv" contenteditable="true">lorem ipsum <spanclass="highlight">indol|or sit</span> amet consectetur <span class='tag'>adipiscing</span> elit</div>
I would like to get the current cursor position including html tags. My code :
var offset = document.getSelection().focusOffset;
Offset is returning 5 (full text from the last tag) but i need it to handle html tags. The expected return value is 40. The code has to work with all recents browsers.
(i also checked this : window.getSelection() offset with HTML tags? but it doesn't answer my question).
Any ideas ?
Another way to do it is by adding a temporary marker in the DOM and calculating the offset from this marker. The algorithm looks for the HTML serialization of the marker (its outerHTML) within the inner serialization (the innerHTML) of the div of interest. Repeated text is not a problem with this solution.
For this to work, the marker's serialization must be unique within its div. You cannot control what users type into a field but you can control what you put into the DOM so this should not be difficult to achieve. In my example, the marker is made unique statically: by choosing a class name unlikely to cause a clash ahead of time. It would also be possible to do it dynamically, by checking the DOM and changing the class until it is unique.
I have a fiddle for it (derived from Alvaro Montoro's own fiddle). The main part is:
function getOffset() {
if ($("." + unique).length)
throw new Error("marker present in document; or the unique class is not unique");
// We could also use rangy.getSelection() but there's no reason here to do this.
var sel = document.getSelection();
if (!sel.rangeCount)
return; // No ranges.
if (!sel.isCollapsed)
return; // We work only with collapsed selections.
if (sel.rangeCount > 1)
throw new Error("can't handle multiple ranges");
var range = sel.getRangeAt(0);
var saved = rangy.serializeSelection();
// See comment below.
$mydiv[0].normalize();
range.insertNode($marker[0]);
var offset = $mydiv.html().indexOf($marker[0].outerHTML);
$marker.remove();
// Normalizing before and after ensures that the DOM is in the same shape before
// and after the insertion and removal of the marker.
$mydiv[0].normalize();
rangy.deserializeSelection(saved);
return offset;
}
As you can see, the code has to compensate for the addition and removal of the marker into the DOM because this causes the current selection to get lost:
Rangy is used to save the selection and restore it afterwards. Note that the save and restore could be done with something lighter than Rangy but I did not want to load the answer with minutia. If you decide to use Rangy for this task, please read the documentation because it is possible to optimize the serialization and deserialization.
For Rangy to work, the DOM must be in exactly the same state before and after the save. This is why normalize() is called before we add the marker and after we remove it. What this does is merge immediately adjacent text nodes into a single text node. The issue is that adding a marker to the DOM can cause a text node to be broken into two new text nodes. This causes the selection to be lost and, if not undone with a normalization, would cause Rangy to be unable to restore the selection. Again, something lighter than calling normalize could do the trick but I did not want to load the answer with minutia.
EDIT: This is an old answer that doesn't work for OP's requirement of having nodes with the same text. But it's cleaner and lighter if you don't have that requirement.
Here is one option that you can use and that works in all major browsers:
Get the offset of the caret within its node (document.getSelection().anchorOffset)
Get the text of the node in which the caret is located (document.getSelection().anchorNode.data)
Get the offset of that text within #mydiv by using indexOf()
Add the values obtained in 1 and 3, to get the offset of the caret within the div.
The code would look like this for your particular case:
var offset = document.getSelection().anchorOffset;
var text = document.getSelection().anchorNode.data;
var textOffset = $("#mydiv").html().indexOf( text );
offsetCaret = textOffset + offset;
You can see a working demo on this JSFiddle (view the console to see the results).
And a more generic version of the function (that allows to pass the div as a parameter, so it can be used with different contenteditable) on this other JSFiddle:
function getCaretHTMLOffset(obj) {
var offset = document.getSelection().anchorOffset;
var text = document.getSelection().anchorNode.data;
var textOffset = obj.innerHTML.indexOf( text );
return textOffset + offset;
}
About this answer
It will work in all recent browsers as requested (tested on Chrome 42, Firefox 37, and Explorer 11).
It is short and light, and doesn't require any external library (not even jQuery)
Issue: If you have different nodes with the same text, it may return the offset of the first occurrence instead of the real position of the caret.
NOTE: This solution works even in nodes with repeated text, but it detects html entities (e.g.: ) as only one character.
I came up with a completely different solution based on processing the nodes. It is not as clean as the old answer (see other answer), but it works fine even when there are nodes with the same text (OP's requirement).
This is a description of how it works:
Create a stack with all the parent elements of the node in which the caret is located.
While the stack is not empty, traverse the nodes of the containing element (initially the content editable div).
If the node is not the same one at the top of the stack, add its size to the offset.
If the node is the same as the one at the top of the stack: pop it from the stack, go to step 2.
The code is like this:
function getCaretOffset(contentEditableDiv) {
// read the node in which the caret is and store it in a stack
var aux = document.getSelection().anchorNode;
var stack = [ aux ];
// add the parents to the stack until we get to the content editable div
while ($(aux).parent()[0] != contentEditableDiv) { aux = $(aux).parent()[0]; stack.push(aux); }
// traverse the contents of the editable div until we reach the one with the caret
var offset = 0;
var currObj = contentEditableDiv;
var children = $(currObj).contents();
while (stack.length) {
// add the lengths of the previous "siblings" to the offset
for (var x = 0; x < children.length; x++) {
if (children[x] == stack[stack.length-1]) {
// if the node is not a text node, then add the size of the opening tag
if (children[x].nodeType != 3) { offset += $(children[x])[0].outerHTML.indexOf(">") + 1; }
break;
} else {
if (children[x].nodeType == 3) {
// if it's a text node, add it's size to the offset
offset += children[x].length;
} else {
// if it's a tag node, add it's size + the size of the tags
offset += $(children[x])[0].outerHTML.length;
}
}
}
// move to a more inner container
currObj = stack.pop();
children = $(currObj).contents();
}
// finally add the offset within the last node
offset += document.getSelection().anchorOffset;
return offset;
}
You can see a working demo on this JSFiddle.
About this answer:
It works in all major browsers.
It is light and doesn't require external libraries (apart from jQuery)
It has an issue: html entities like are counted as one character only.
I need to get the position of the selected text within a content non-editable div (not a textarea, not a rtf editor, just a simple div)
I want to do this in order to enable users to select pieces of an article and "highlight it", by wrapping it in a span with a different background and, of course, an article is build with divs and/or p-s etc, not textareas or rtfs
Any ideas?
P.s. You can also use jQuery :D
P.s.s. I need the position of the selection, not the selection itself. Aka: it start from index I to index J. I need this because the normal method of finding the text in the parent does not always return a unique result, which would suck :)
If you just want to change the background of the selected text, the easiest way to do this is by using document.execCommand(). See my answer here: Change CSS of selected text using Javascript
//Wrap selected text in span tags with the class 'hl'
//Take some action after (in this case, a simple alert)
$("p").live("mouseup",
function() {
selection = getSelectedText();
if(selection.length >= 3) {
$(this).html($(this).html().replace(selection, $('<\/span>').attr({'class':'hl'}).html(selection).parent().html()) );
alert(selection);
}
}
);
//Grab selected text
function getSelectedText(){
if(window.getSelection){
return window.getSelection().toString();
}
else if(document.getSelection){
return document.getSelection();
}
else if(document.selection){
return document.selection.createRange().text;
}
}
Code comes from here: http://esbueno.noahstokes.com/post/92274686/highlight-selected-text-with-jquery
You can check if text is selected by running :
window.getSelection and document.getSelection() and document.selection
(because browsers can check this i different ways)
and then search for div containing this text .
For getting the position of the selection, try these links:
http://bytes.com/topic/javascript/answers/153164-return-selectionstart-div
Set cursor position on contentEditable <div>
Well, even though you found a solution to the problem stated in your 2nd paragraph, i don't think the answer to your main question has been given. :)
The object Selection has a property named anchorOffset, giving exactly what you asked for (the position of the selected text within an element). The above link will tell you about which browsers support it, i'm afraid IE <9 might not.
function show_selected()
{
var sel = selection();
console.log(sel.anchorOffset + ':' + sel);
}
Now if you bind show_selected to, say, mouseup, you will see the offset and the selected text printed on the js console.
The fonction selection may be the following, supposed to be cross-browser:
function selection()
{
var sel;
if(window.getSelection){
sel = window.getSelection()
}
else if(document.getSelection){
sel = document.getSelection()
}
else if(document.selection){
sel = document.selection.createRange()
}
return sel
}