Rangy and IE8 - positioning caret after element at end of paragraph - javascript

I'm using Rangy to perform several operations in a rich text editor (designmode = "on"). One of these functions is pasting formatted content which can represent certain pre-defined characters the user has created before-hand. All of the text content is held in paragraph elements. The user may start with this:
<p>The following is a special character: |</p>
where the pipe (|) is the caret position. They then choose to paste one of the 'special' characters via a button on the editor to end up with this:
<p>The following is a special character: <span class="read-only" contenteditable="false">SPECIAL</span>|</p>
The action uses Rangy behind the scenes to maintain the position of the caret (SelectionSaveRestoreModule) during the internal paste process which could be post-paste-processing the text in the editor and which likely messes up the position of the cursor otherwise.
However, in IE8 the caret cannot be placed after the <span> since there appears to be a bug which makes it an invalid position. As a result the cursor appears before the <span> element and it is not even possible to move the cursor after the span with the keyboard cursor controls. In fact, it even prevents the cursor moving on to any following paragraphs.
I have experimented with several techniques over recent days, including placing extra characters after the <span>s with some success. However those extra characters obviously cause confusion for the user when they appear and are not ideal. Using the zero-width space is visually better but attempting to tidy them up after the paste operation causes issues.
I need a 'tidy' method of supporting this user requirement for the special characters and I freely accept I may be approaching this in the wrong way.

I have a solution which seems to be working in my tests so far, but when I look at it it still fills me with a feeling that there must be a better way (not to mention a sense of dread).
What this code tries to do is place a zero-width-space after any read-only span which is at the end of a paragraph. It does this by inspecting the nodes after these elements to determine if there is actually text in them. At the same time it removes any zero-width-spaces which may still be in the text from previous inspections which are now no longer needed.
var ZWS = '\ufeff';
jQuery(_doc.body).find('p').each(function () {
var lastContentEditable = undefined;
// Look through the root contents of each paragraph to remove no-longer require zws fixes
jQuery(this).contents().each(function () {
if (this.nodeType === 3) {
if (this.nodeValue.indexOf(ZWS) != -1) {
// Text node containing a ZWS - remove for now
this.nodeValue = this.nodeValue.replace(new RegExp(ZWS, 'g'), '');
}
// Does this node now contain text?
if (this.nodeValue.length > 0 && lastContentEditable) {
// Found text after a read-only node, ergo we do not need to modify that read-only node at the end
lastContentEditable = undefined;
}
} else if (this.nodeType === 1 && this.getAttribute('contenteditable') === "false") {
// Indicate that this is currently the last read-only node
lastContentEditable = this;
}
});
if (lastContentEditable) {
// It appears that there is a read-only element at the end of the paragraph.
// Add the IE8 fix zws after it.
var node = document.createTextNode(ZWS);
jQuery(lastContentEditable).after(node);
}
});

Related

JS - surroundContents only retains highlight on text about 20% of the highlight attempts

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

Codemirror: Retrieve character index from span tag

So I have a codemirror instance on the left of a document, and an iframe on the right. When the code is updated in the editor, it is written to the iframe.
During this rewrite, I add an index to each and every element that is created using jQuery's $.data function so that whenever the user hovers their mouse over the element it can be highlighted in the editor.
So far I have managed to pick out the required element's position in the editor in terms of where its generated <span class="cm-tag cm-bracket"> tag is and give it a class of cm-custom-highlight.
My question is - is there any way to turn an instance of a source span tag into an actual selection within the editor?
Update: Answered my own question - see below! You can check out my resulting code here.
I answered my own question! How about that?
Turns out CodeMirror has a neat little list of nodes in its display container. All I needed to do was loop through CodeMirror.display.renderedView[lineNumber].measure.map and test each text node's parentNode property to see if it was the same as the span I had highlighted.
The map array is structured like so:
[
0: 0
1: 1
2: text
3: 1
4: 5
...
]
Every text node here refers to a piece of code in the editor and the numbers before and after refer to its character index, so it was pretty easy to find the index that I needed:
var span = $('span.cm-custom-highlight', CodeMirror.display.lineDiv),
lineNumber = span.closest('.CodeMirror-line').closest('div[style]').index(),
lineView = CodeMirror.display.renderedView[lineNumber].measure.map,
char = 0;
for(var i in lineView.measure.map)
{
if(!char &&
typeof lineView.measure.map[i] == 'object' &&
lineView.measure.map[i].parentNode && span[0] == lineView.measure.map[i].parentNode)
{
char = lineView.measure.map[i - 1];
}
}
Sure it's a little messy, but it gets the job done nicely.
You will get better results when using markText rather than directly messing with the editor's DOM. The DOM and view data structure aren't part of the interface, and will change between versions. The editor can also update its DOM at any moment, overriding the changes you made.

How to get cursor HTML offset in contenteditable? [duplicate]

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.

javascript : focusOffset with html tags

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.

Applying DIV/Span tag to a word by specific co-ordinates

Sample HTML Data
<body style="width:300px;">
<h3>Long-Text</h3>
A simple tool to store and display texts longer than a few lines.
The search button will highlight all the words matching the name of objects that are members of the classes listed in searchedClasses, itself a member of the KeySet class. The highlighted words are hypertext.
Edit invokes wscripts/acedb.editor, which by default launches emacs. Edit that file to start another editor in its place.
Save will recover from the emacs but will not destroy it.
Read will read a text file, so you could Search it.
**general** grep is a way to annotate a set of longtexts versus the searchedClasses. It outputs an ace file that you can then hand check and read back in acedb to create XREF from longTexts to genes etc.
<h3>World Wide NotePad</h3>
World wide notepad is a small text editor similar to Microsoft's notepad but has some more useful features like an auto typer to make typing the same sentence or word more easy, also World Wide NotePad has a text to speech feature which reads all text in the current open document and speaks it out load to you.
<h3>Etelka Wide Text Pro Bold Italic</h3>
</body>
For example -> "general" (between ** ) is at x=0 and y=465. I know the x,y position. But How to highlight a word located at specific location ?
Let me explain once again. I want to highlight a word by location.
for example I have a location value (x,y)=(0,625). I want to extract the first word by that location ( assume - at that location - we have word "World" ) Then how to highlight that word ?
Edit :
Here Y co-ordinate is absolute position of entire html document.
The only method I can think of involves wrapping every word in a span element, and then using document.elementFromPoint(x,y) to get the span element at the given location. Something like this:
function highlightWordAtXY(x, y) {
// Get the element containing the text
var par = document.elementFromPoint(x, y),
// textContent or innerText ?
t = "textContent" in par ? "textContent" : "innerText",
// Get the text of the element. No pun intended on the par[t].
text = par[t],
result;
// Wrap a span around every word
par.innerHTML = text.replace(/\b(\w+)\b/g, "<span>$1</span>");
// Get the elementFromPoint again, should be a span this time
result = document.elementFromPoint(x, y);
// Check that we actually clicked on a word
if (result == par)
return false;
// Wrap HTML text around the text at x, y
result[t] = '<span class="highlight">' + result[t] + '</span>';
// Restore the content with the wrapped text
par.innerHTML = par[t];
}
Example at http://jsfiddle.net/BSHYp/1/show/light/ - click a word and watch it highlight.
Some important caveats here:
Each block of text must be wrapped in an element (such as <p> or <div>). You should be wrapping paragraphs in <p> tags anyway,
The element at the given location (x, y) must only have text in it, no child HTML elements. Text nodes with sibling HTML elements will have them removed (e.g. Clicking "Some" or "here" in Some <b>text</b> here will remove the <b> tags). Dividing them into separate <span> elements would be the only solution without building a much more complex routine,
IE will throw an "Unknown runtime error" if you try and add a block level element to a <p> tag,
On very, very, very large blocks of text you might run into performance issues. Break them up where applicable.

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