Empty and append expanding height of element - javascript

I'm running this code:
$('#storeTable').empty();
$('#storeTable').append("<tr>");
$('#storeTable').append("<td>");
$('#storeTable').append(returnData["1"]["ID"]);
$('#storeTable').append("</td>");
$('#storeTable').append("</tr>");
However if I run it multiple times in one page load, the 'storeTable' element gets taller and taller with every run. Am I missing something obvious, is this a gotcha of jQuery/JavaScript, is it the fault of my browser (Chrome), or am I doing something wrong?
The code obviously needs refining, I'm just trying to get a bare-bones implementation of a dynamic section of a page.
If you'd like any other details, please ask, rather than just downvoting without a comment.
storeTable is, of course, a table, too.

You can't use .append() to append partial pieces of HTML. .append() only appends whole formed objects and when it appends them it appends them as the last child of the target object.
To add to that, some browsers are picking about how you can or cannot create/remove content in tables.
Assuming #storeTable is the <table> tag, you could assign .html() to create a whole new table all at once:
$("#storeTable").html("<tr><td>" + returnData["1"]["ID"] + "</td></tr>");
Working demo: http://jsfiddle.net/jfriend00/5BVdX/

$('#storeTable').empty();
// Will create three rows, one after another
$('#storeTable').append("<tr><td>123</td></tr>");
$('#storeTable').append("<tr><td>456</td></tr>");
$('#storeTable').append("<tr><td>789</td></tr>");
// Will create three rows, each next replaces previous
$('#storeTable').html("<tr><td>123</td></tr>");
$('#storeTable').html("<tr><td>456</td></tr>");
$('#storeTable').html("<tr><td>789</td></tr>");

Related

Create new DOM element if a specific height was reached with part of the old content from DOM element before

Update: 27th December 2016
I did change the heading, since every DOM element could be the target (it actually doesn't matter if it is a <p> element or not).
I've provided some more informations about what I'm using and what I'm trying to achieve. Maybe there are native electron ways to achieve this? Or libs which could help me too?
Product: I'm going to extract tgz files with XMLs in it. Those XMLs will be used to automatically fill tables in the finished product. After that the tables and paragraphs will be editable where users can add new rows to the tables and also add new paragraphs to the page.
Framework: I'm using electron to fire the whole thing up.
Backend: NodeJS 7.x.x to make use of ES6 features
Libraries: jQuery, Bootstrap, Angular, Materialize, lodash, async, moment
Please keep in mind that I already did achieve all of my product needs. My original question was and still is if there is a more performant way of doing this:
I have a html page which can have 'n' containers called pages. A page can hold multiple <p> elements. This <p> elements are set to contenteditable="true".
Now I'm trying to create a javascript function which is checking the single page height with something like this:
// Set max container height to 10cm.
let containerMaxHeight = 377.95276 // 1 cm = 37.795276px;
if(containerElement.clientHeight > containerMaxHeight){
/**
* do desired stuff.
*/
}
everything easy so far. The function is getting the innerHTML of the <p> element which is currently beeing edited and "break the site" into a new site if the page height is above the limit. I have thought out a recursion wich is removing words (most of the time 1-3) of the old <p> element and inserting them to a newly created page with a <p> element until the maximum height of the old page is set to its maximum value.
Here is an example of my recursion (simplified) which is removing words from the end of innerHTML like this:
let lastWordToBeRemoved = oldParagraphElement.split("\\s+").pop();
// append old value to new <p>
newParagraphElement.innerHTML += lastWordToBeRemoved;
// remove last Word from old <p>
oldParagraphElement.innerHTML.slice(0, -lastWordToBeRemoved.length);
/**
* Recheck height of old page container if it is above the
* maximum redo above code
*/
I've startet out with this example:
https://delight-im.github.io/HTML-Sheets-of-Paper/
as you can see the pages are getting bigger and bigger if you edit them. I've already prevented that with my JS function.
Now that you have an idea of what I'm doing: Is there a more performant and or elegant way of doing this? I'm highly interested to hear how you would solve this problem.
If there is anything still unclear let me know, I will update my answer.
Thank you in advance!
Regards,
Megajin
Instead of splitting words, I think you should insert another p element into the expected position instead. Then you can easily move the exceeding paragraph into the new page. For example
paragraphElement.innerHTML = paragraphElement.innerHTML.replace(lastWordToBeRemoved, '</p><p class="exceeding-paragraph">' + lastWordToBeRemoved);
newPage.insertBefore(oldPage.querySelector('.exceeding-paragraph'), newPage.firstElementChild);

Get dynamic text from selected object - (by ID and "active" class) - jQuery

My main mission: Is to get the text of the next and the previous objects to the chosen object - To display the image (and its titles) Previous & Next.
Before that I have a problem: to get text of a selected object, from an index to a variable.
The problem: Every time I pick a random object, the variable does not change but the text is added to the existing text in the index.
I made a DEMO, would appreciate your help.
$(document).ready(function hintProject(){
$('#nextProject, #prevProject').click(function(){
subtitle = null;
subtitle = $('#client-sub.active').justtext();
$('#next_target_title').text(subtitle);
alert (' text::: ' + subtitle );
});
});
It looks like jQuery simply can't find the objects you're specifying. I don't think the problem is with the snippet in the question. I think the problem is with your document ready function.
To debug, try simplifying your problem by cutting out all of the additional complexity of the setup script and just set up an HTML page that is in the state you want. It's much easier to understand 1 problem than 2 or more.
Also, try simplifying how you're specifying an active item: a single class on the portfolio item would make your life easier. Then you can specify css and such based on the parent instead of adding multiple classes to multiple things inside the each portfolio item.

Using jquery to copy a portion of a table in the most optimized way

I am using JQuery to manipulate a page which I do not have access to modify server-side. One of the main things I need to do is create a copy of just a sub-section of one of the tables on the page. More specifically, I need to create 2 tables, one which is a copy of just the first two rows of the table and another which is just the first column.
After optimizing it as far as I could, I'm fairly happy with the performance of the row copy but the column copy is still a bit on the slow side.
I have the following, where sourceTable is the original table and titleColBody is the tbody of a new table created earlier:
sourceTable.find("tr").each(function(){
titleColBody.append(
$("<tr></tr>").append($(this).children(":first").clone())
);
});
On a table with roughly 50 rows and a huge number of columns, this takes approx. 350ms in IE8. Not terrible, but I would like to bring this down a little if possible.
My question is if there is a more efficient way of doing this in JQuery.
Similarly, I create the copy of the first 2 rows of the table as below.
headerTable.find("tbody")
.append(sourceTable.find("tr:eq(0)").clone())
.append(sourceTable.find("tr:eq(1)").clone());
This is fairly quick, however if there is a better way of doing it I would be happy to hear it.
Any optimization at all would be greatly appreciated.
Seems like this might be a tad bit faster for the columns, this way you'll only grab one resource set instead of grabbing two sets (one for the TRs and then one for the child TDs):
sourceTable.find("tr > td:first-child").each(function(){
titleColBody.append($("<tr></tr>").append($(this).clone()));
});
Also on another note, if the "titleColBody" is a pointer to a DOM object that causes the browser to have to render the page when it's updated, you're better off appending to a documentFragment and then appending that fragment (so the browser only re-renders once).
For instance:
var titleCol = document.createDocumentFragment();
sourceTable.find("tr > td:first-child").each(function(){
titleCol.append($("<tr></tr>").append($(this).clone()));
});
titleColBody.append(titleCol);

javascript innerHTML without childNodes?

im having a firefox issue where i dont see the wood for the trees
using ajax i get html source from a php script
this html code contains a tag and within the tbody some more tr/td's
now i want to append this tbody plaincode to an existing table. but there is one more condition: the table is part of a form and thus contains checkboxe's and drop down's. if i would use table.innerHTML += content; firefox reloads the table and reset's all elements within it which isnt very userfriendly as id like to have
what i have is this
// content equals transport.responseText from ajax request
function appendToTable(content){
var wrapper = document.createElement('table');
wrapper.innerHTML = content;
wrapper.setAttribute('id', 'wrappid');
wrapper.style.display = 'none';
document.body.appendChild(wrapper);
// get the parsed element - well it should be
wrapper = document.getElementById('wrappid');
// the destination table
table = document.getElementById('tableid');
// firebug prints a table element - seems right
console.log(wrapper);
// firebug prints the content ive inserted - seems right
console.log(wrapper.innerHTML);
var i = 0;
// childNodes is iterated 2 times, both are textnode's
// the second one seems to be a simple '\n'
for(i=0;i<wrapper.childNodes.length;i++){
// firebug prints 'undefined' - wth!??
console.log(wrapper.childNodes[i].innerHTML);
// firebug prints a textnode element - <TextNode textContent=" ">
console.log(wrapper.childNodes[i]);
table.appendChild(wrapper.childNodes[i]);
}
// WEIRD: firebug has no problems showing the 'wrappid' table and its contents in the html view - which seems there are the elements i want and not textelements
}
either this is so trivial that i dont see the problem OR
its a corner case and i hope someone here has that much of expirience to give an advice on this - anyone can imagine why i get textnodes and not the finally parsed dom elements i expect?
btw: btw i cant give a full example cause i cant write a smaller non working piece of code
its one of those bugs that occure in the wild and not in my testset
thx all
You are probably running into a Firefox quirk of following the W3C spec. In the spec the whitespace between tags are "text" nodes instead of elements. These TextNodes are returned in childNodes. This other answer describes a workaround. Also Using something like JQuery makes this much easier.
I would expect this behavior in any browser as the += operand overwrites what is already in the table by definition. Two solutions:
Instead of receiving HTML code from your PHP file, have the PHP generate a list of items to add to the table. Comma/tab separated, whatever. Then use Table.addRow(), Row.addCell() and cell.innerHTML to add the items to the table. This is the way I would suggest doing it, no point in creating GUI elements in two separate files.
The other solution is to save all the form data that's already been entered to local JavaScript variables, append the table, and then reload the data into the form fields.
Well, returning a JSON object with the new data seems like the best option. Then, you can synthesize the extra table elements by using it.
In case one is forced to get plain HTML as response, it is possible to use var foo = document.createElement('div');, for example, and then do foo.innerHTML = responseText;. This creates an element that is not appended to anything, yet hosts the parsed HTML response.
Then, you can drill down the foo element, get the elements that you need and append them to the table in a DOM-friendly fashion.
Edit:
Well, I think I see your point now.
wrapper is a table element itself. The nodes reside under the tbody, a child of wrapper which is its lastChild (or you can access it via its tBodies[0] member, in Firefox).
Then, using the tBody element, I think that you would be able to get what you want.
BTW, You do not need to append the wrapper to the document before appending its children to the table, so no need to hide it etc.

Insert rows into table

What is the best plain javascript way of inserting X rows into a table in IE.
The table html looks like this:
<table><tbody id='tb'><tr><td>1</td><td>2</td></tr></tbody></table>
What I need to do, is drop the old body, and insert a new one with 1000 rows. I have my 1000 rows as a javascript string variable.
The problem is that table in IE has no innerHTML function. I've seen lots of hacks to do it, but I want to see your best one.
Note: using jquery or any other framework does not count.
Here's a great article by the guy who implemented IE's innerHTML= on how he got IE to do tbody.innerHTML="<tr>...":
At first, I thought that IE was not
capable of performing the redraw for
modified tables with innerHTML, but
then I remembered that I was
responsible for this limitation!
Incidentally the trick he uses is basically how all the frameworks do it for table/tbody elements.
Edit: #mkoryak, your comment tells me you have zero imagination and don't deserve an answer. But I'll humor you anyway. Your points:
> he is not inserting what i need
Wha? He is inserting rows (that he has as an html string) into a table element.
> he also uses an extra hidden element
The point of that element was to illustrate that all IE needs is a "context". You could use an element created on the fly instead (document.createElement('div')).
> and also the article is old
I'm never helping you again ;)
But seriously, if you want to see how others have implemented it, take a look at the jQuery source for jQuery.clean(), or Prototype's Element._insertionTranslations.
Do as jQuery does it, eg. add <table> and </table> around it, insert into document and move the nodes you want to where you want them and ditch the temp-element.
the code ended up being this:
if($.support.scriptEval){
//browser needs to support evaluating scripts as they are inserted into document
var temp = document.createElement('div');
temp.innerHTML = "<table><tbody id='"+bodyId +"'>"+html;
var tb = $body[0];
tb.parentNode.replaceChild(temp.firstChild.firstChild, tb);
temp = null;
$body= $("#" + bodyId);
} else {
//this way manually evaluates each inserted script
$body.html(html);
}
Things that beed to exist beforehand: a table that has a body with id of 'bodyId'. $body is a global variable (or the function has a closure on it), and there is a bit of jquery in there too, because IE does not evalute scripts that are inserted into the html on the fly.
I had the same problem (as do lots of other people) and after a lot of playing around here's what I got to work.
You have to make a tr via document.createelement ('tr') then make a td, the same way.
appendchild the td to the tr, appendchild the tr to tbody (not table) THEN you can innerhtml the td you created and it will work.
This was ie8 I was using. Basically the table structure has to be made with createelement but the rest of it can be innerHTMLed. I was doing this watching in the IE8 debugger and it would say it would add it (if I did tr.innerhtml="blah") and give no error, but it wouldn't display, and the html dom view showed a very broken table (no td ever showed up, but the /td did)
So when finally I did the tr AND td by createelement calls, it created a correct looking dom and drew the page correctly.

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