Mobile app version of vmapp.org
Login or Join
Welton855

: Can I set Cache-Control in the .htaccess file for a specific part of a document (just a section of the ) I noticed, by using Google Page Speed Insights, that if I structure my HTML to load

@Welton855

Posted in: #CacheControl #Expires #Htaccess #HttpHeaders #Performance

I noticed, by using Google Page Speed Insights, that if I structure my HTML to load the critical, above-the-fold content first, my page will improve performance - and it woks (with now current perf. of Mobile 71/100 - Pc 87/100).

My question is, with Apaches's mod_header activated, and with no content inside my <head> tag, is it possible to set Data Expires for any part of my page (inside the body, eg)?

10.01% popularity Vote Up Vote Down


Login to follow query

More posts by @Welton855

1 Comments

Sorted by latest first Latest Oldest Best

 

@Cugini213

The expires header is related to the page, not fragments of it.

Lets go over the basics.

You send HTML to the browser, all of it or a stream, doesn't matter for the example.

The browser receives it and starts parsing it. At the same time, once it starts parsing, all the other linked files are called, like images, css, js, etc. Some parallel connections are established and some of the linked files start coming; the browser detects them and assigns the right parser/renderer to work with the file.

If the file is an image it will be displayed on the screen. if it is a CSS, the parser starts applying the rules to the received HTML and shows/modifies the presentation of the content. If it is a script, it reads it looking for a trigger, if there is none, the file just stays on memory, if there is a trigger, the called action/function starts working.

Above the fold is a term that refers to the content that is viewed first on the screen, it comes from the news papers.

CSS and JS are not above the fold, they are asynchronous or parallel to the rendering of the content; CSS affects the whole document, JS affects whatever it was programmed to do.

If what you want to do is control the cache of the CSS and JS files, you can use rules on your .htaccess, like so

<FilesMatch ".(css|js)$">
Header set Cache-Control "max-age=31536000, public, s-maxage=31536000"
Header set Pragma "cache"
</FilesMatch>


or like this

<IfModule mod_expires.c>
ExpiresActive On
ExpiresDefault "access plus 1 month"
ExpiresByType application/x-javascript "access plus 1 month"
ExpiresByType text/css "access plus 1 month"
</IfModule>


it is not possible to affect part of the content of a page, unless that content (HTML file) is inserted as an iframe; in that situation, you are still affecting a different file, but the final page, may look like only part is affected by cache rules.

10% popularity Vote Up Vote Down


Back to top | Use Dark Theme