Currency conversions and exchange rate

[gaugelive]

Problem:
I have prices that are fetched from a DB to several pages on my site.
The prices all need to be displayed as one USD cost.

The prices are generally in 2 currencies. e.g. Euros and GB Pounds.

Essentially i need to get the euro price, get the pound price covert each of them to USD and add them up, display the price and display the rate of exchange applied.

I would like the prices updated daily based on rates from the XML file at http://www.ecb.int/stats/exchange/eurofxref/html/index.en.html

Prices need to be updated once a day only.

My initial idea was to fetch the xml rates once a day, and convert the prices i have on each request.
But thats perhaps a lot of work as the price will be the same for the entire 24hour period..

incase the currency site and feed are unavailable on a particular day i would like to use the previous days cached rate and display prices based on that ROE.

I am looking on any suggestions, ideas on how to go about this. Thanks.

[Installer]

Store the rates in a db table, and fetch them as needed. You could also store the time of the last update. If it's not within the last day, then attempt to update them.

[gaugelive]

thanks for your reply. This is what i have in mind now---set up a script to fetch the xml file retreive the rates, currencies i need do some conversions that may be needed put it into a db table..
then run the page as a daily cron via wget.

[bpat1434]

1.) Set up a cron-job (or service) to run daily at like 12:00 pm GMT (noon) that will get the XML file, examine it, and update your database.
2.) Each time you need to "exchange" from one currency to the next, quickly query the DB.

That is a lot easier because then you know that for a fact the information will be updated, unless it's unavailable (you can code that into the Cron script). And your other PHP scripts will get their exchange rates from a local DB, so no matter what, the information should be available.

So here are the basic steps:

• Create a file xrate.php

  • Get the XML (http://www.ecb.int/stats/eurofxref/eurofxref-daily.xml)

  • IF AVAILABLE:

    • Parse information using [man]simpleXML[/man] or [man]DOMXML[/man]

    • Insert into the database

  • ELSE

    • Don't update, dispatch an email to you noting the failure.

    • Log the failure to a log script or whatever...

• Cron Job (or Service)

  • Set up so that it runs: 0 12 "/home/usr/username/public_html/xrate.php"
    

  
  

• Your other files
  

  • Query db for proper exchange rate

  • Do calculations, display information

Understand?

[gaugelive]

thanks brett for the breakdown..understood.
looks like the solution i need...appreciate your help.