Will updating latest Twenty Ten theme kill customizations?

If you have modified theme files, yes, you will lose those changes. That’s why you should always make changes in a Child Theme.

Changes made in theme options or via a plugin (i.e. custom CSS) won’t be lost.

Yes, you should always be using the most current version of WP and your theme.

It’s now time to make a child theme and move over all the customizations to it, which is the right way.

Here is all the changes of TwentyTen from 1.4 @21040 to 1.5 @23125
(from a quick browse, I see no fix for security issue.)

Meanwhile, depends on how heavy the changes made to the theme itself, during the time you work on childtheme there should not be any worry on security issue, just make sure that you have WP core up to date and keep all the plugins up to date too.

@wpyogi – Thank you so much for the prompt reply and help. I’m learning as I go here… Thank you!

@paulwp – Thank you! I run a basic blog on this theme and didn’t make too many heavy modifications. If they’re lost upon updating then I’ll live and start over doing it the correct way. Really helpful to know this stuff… I appreciate your help!

didn’t make too many heavy modifications. If they’re lost upon updating then I’ll live and start over doing it the correct way.

Download a blank TwentyTen childtheme from here.
https://quirm.net/themes/twenty-ten-child/

Upzip it.

Change folder’s name
from twentyten-child
to olive

Open this file style.css
change Theme Name:Twenty Ten Child
to Theme Name:Olive

Upload this folder to wp-content/themes
so now we will have wp-content/themes/olive
along with the already there wp-content/themes/twentyten

Under Appearance > Themes pick this theme and make modifications in this theme only, once done you can click update to the TwentyTen (parent).

@paulwp – Awesome! Thank you again.

So, I still have a question on the child’s style.css file. I understand what values to add in the header code, but does the file contain only changes? Or does it include a mere duplicate of all original (parent) coding with changes applied?

If the child’s style.css contains this at the top

/* Import layout */
@import url(../twentyten/style.css);

then you are working on top of (overriding) the parent’s css, just redeclare only what you want changed below that line. So yes, this will contain only changes but technically it loaded the parent’s into it already.

This is the most efficient way for most use cases, so stick to this unless you are completely reconstructing the parent’s layout or require lots of modifications then just remove that line and do everything from scratch.

Also, at the very top of child’s style.css make sure this line Template: twentyten is always there, it tells WP that this theme is a child of that parent.

I really appreciate your help & time here. I’m basically making modifications to fonts, colors, etc… nothing too sophisticated.

So, only additional/modifications to .css reside in this file? For example, if I only made two changes to the .css, would my header code look something like this:

/*
Theme Name: Twenty Ten Child
Description: Child theme for twentyten
Author: Olive
Template: twentyten
*/

@import url("../twentyten/style.css");

}
#access li:hover > a,
#access ul ul :hover > a {
	background: #625148;
	color: #fff;
}

#content .entry-title {
????color:?#000000;
????font-size:?21px;
????font-weight:?bold;
????line-height:?1.3em;
????margin-bottom:?0;
}

And the rest of the (child) .css file blank? Just want to make sure I’m placing code elements correctly and understanding how this works… thank you again

Absolutely – correct ?? .

Great, thank you so much. This was incredibly helpful.

Glad to hear that — we try around here. paulwp explained it so elegantly as well…and you jumped right in. Nice all around.

Hmmm!

I even learned a little something from this! I had forgotten completely about the CSS “import” directive.

The thing I usually did is just backup the modified CSS file(s) and then rename the newer CSS files so that mine will continue to work on the new theme when I go to copy them back to the original theme folder, but the other idea made a lot of sense!

Thanks from me too!