当内容溢出div的固定高度时，如何创建新的div？

Question

CSS

.page{ 
      width: 275px;
      hight: 380px;
      overflow: auto;
     }

HTML

<div class="page">dynamic text</div>

How to create a new div when the dynamic text is overflowing past the fixed height of the div?

Example:

<div class="page">Some dynamic texts will appear here</div>

When the dynamic text is overflowing past the fixed height of the div, the content above will be appear like this.

<div class="page">Some dynamic</div>
<div class="page">texts will</div>
<div class="page">appear here</div>

I've tried using wordwrap function in PHP wordwrap($dynamic_text, 600, '</div><div class="page">'); it's can running, but it had a problem when the character was copied from Ms.Words. So, by detecting the overflowing text, cut it, and then paste it into the new div element is the better solustion, i guess. But, I don't know how to do this solution using JQuery or Javascript.

Any ideas? Thanks in advance!

Answer 1

You can do it, and it's way more than just a couple lines of code. It took a very experienced developer a couple days. Sorry, can't share the code.

Javascript: Put the whole content into the div. You may keep it hidden or out of the DOM for a while. Traverse the div's children. Find the one whose top+scrollHeight exceeds the div's height. Traverse it recursively. Eventually, you will either find an indivisible element, eg, an image, that doesn't fit, or a position within a text node to split the text at. Remove that part and all further elements from the div. Add them to a new one.

There are a lot of details to address, so it's not simple. But doable.

Answer 2

I just had something similar working today while I was searching for an answer but there doesn't seem to be anything straight forward.

Although I am using Array.reduce() you should be able to do this with Array.forEach() or any other iterating code you like.

words.reduce(function(acc, value) 

This is done by calculating if the element will overflow if we add another word to it before we actually render it. The hacky thing here is to add another block element inside of it with visibility: hidden .

element.innerHTML = '<div style="visibility: hidden; height: 100%; width=100%">' + textToBeAdded + '</div>';

That way the block element still takes its parents dimensions and the parent element can be checked for overflow.

The way to check for overflow is to compare the element's scrolling height to its height:

if (element.scrollHeight > element.offsetHeight) 

If it overflows we leave it as is and create a new element and put the current value (word) in the iteration. Then we attach it to the same DOM tree as the previous element (as its parent's child... like having a new brother 😜)

var newPageEl = document.createElement('div');
newPageEl.classList = 'page';
newPageEl.textContent = word;
parentElement.appendChild(newPageEl);

Hope this makes sense.

 var page = document.getElementsByClassName('page')[0]; if (page.scrollHeight > page.offsetHeight) { // is overflowing fixOverflow(page); } function fixOverflow(element) { var words = element.textContent.split(' '); // delete previous text content element.textContent = ''; words.reduce(function(acc, value) { // store current element's text var currentElementText = element.textContent.toString().trim(); var textToBeAdded = currentElementText + ' ' + value; element.innerHTML = '<div style="visibility: hidden; height: 100%; width=100%">' + textToBeAdded + '</div>'; if (element.scrollHeight > element.offsetHeight) { // is overflowing with the new word element.innerHTML = ""; // leave the last page element as is element.textContent = currentElementText; // create another element with the new value to be added // ** IMPORTANT replace the memory of the previous element variable element = createPageElement(value); // add it to the same DOM tree as the previous page element page.parentElement.appendChild(element); // could also be document.getElementById('page-container').appendChild(element); } else { // if not overflowing add another word element.innerHTML = currentElementText + ' ' + value; } }, ""); } function createPageElement(text) { // create element with class page var newPageEl = document.createElement('div'); newPageEl.classList = 'page'; newPageEl.textContent = text; return newPageEl; }