Category Archives: Internet

DNS RFC References

https://tools.ietf.org/html/rfc1123
:RFC standard for naming host names

2.1 Host Names and Numbers

The syntax of a legal Internet host name was specified in RFC-952
[DNS:4]. One aspect of host name syntax is hereby changed: the
restriction on the first character is relaxed to allow either a
letter or a digit. Host software MUST support this more liberal
syntax.

Host software MUST handle host names of up to 63 characters and
SHOULD handle host names of up to 255 characters.

Whenever a user inputs the identity of an Internet host, it SHOULD
be possible to enter either (1) a host domain name or (2) an IP
address in dotted-decimal (“#.#.#.#”) form. The host SHOULD check
the string syntactically for a dotted-decimal number before
looking it up in the Domain Name System.

Other references
DOMAIN NAMES – CONCEPTS AND FACILITIES

DOMAIN ADMINISTRATORS OPERATIONS GUIDE

Facebook Scraper-clear cache

If you want to control how your data looks after posting to Facebook. You will want to use the scraper debug tool.

This tool came in handy after a user wanted a particular image to show instead of a random image. The debugger allowed us to see what exactly facebook was pulling. The tool also advise us on some warning and issues we have within our codebase.

We had to edit the functions.php file and had the below snippet .Thanks to https://wordpress.org/support/topic/change-the-og-image-property


add_filter('wpseo_pre_analysis_post_content', 'mysite_opengraph_content');
function mysite_opengraph_content($val) {
return preg_replace("/<img[^>]+>/i", "", $val);
}

We also needed to edit the header.php file and add the below snippet

<meta property="og:image" content="http://example.com/hmm.jpg" />

**of course changing the values to match our website*

After making the needed changes, you can request a rescrape using the scraper tool. This can also be down via the linux command line with curl. You will need access token for this to work.

Example

curl -F access_token="<token>" -F id="cnn" -F scrape=true https://graph.facebook.com

https://developers.facebook.com/tools-and-support/

API Docs

Some of the warning we received were related to Open Graph protocol
Open Graph protocol