Re: proper way to check if a container is empty?

This WebDNA talk-list message is from

2000


It keeps the original formatting.
numero = 27127
interpreted = N
texte = >The best way is to do this: > >[showif [URL][NIS][/URL]=%5BNIS%5D] > [math show=f]NIS=0[/math] >[/showif] > >in general, because if it's possible that a variable may have user input, >they may be putting in characters that are comparison operators (like ><,>,=,!) that could mess up statement. This would resolve those problems.In general this is true, but you can take advantage of the left-to-right parsing of the [ShowIf] context this way:[ShowIf =[NIS]](Notice there's only one space after the ShowIf) this reads as show if 'nothing' equals the value of the [NIS] variableNow I should also point out that this is very different from checking if a variable is undefined. It's one thing to say that a variable has been defined, and it has a value of , the empty string. It's another thing entirely to say that a variable has not been defined at all, and it has no value whatsoever.Technical Support ********************************** Smith Micro, Internet Solutions Div | Formerly, Pacific Coast Software 16855 West Bernardo Drive | ------------------------- Suite 380 | eCommerce (WebCatalog) San Diego, CA 92127 | Software & Site Development 858.675.1106 | http://www.smithmicro.com 858.675.0372 (fax) **********************************------------------------------------------------------------- Brought to you by CommuniGate Pro - The Buzz Word Compliant Messaging Server. To end your Mail problems go to .This message is sent to you because you are subscribed to the mailing list . To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to Associated Messages, from the most recent to the oldest:

    
  1. Re: proper way to check if a container is empty? (Kenneth Grome 2000)
  2. Re: proper way to check if a container is empty? (Webcat 2000)
  3. Re: proper way to check if a container is empty? (WebDNA Support 2000)
  4. Re: proper way to check if a container is empty? (John Butler 2000)
  5. Re: proper way to check if a container is empty? (Howard Wolosky 2000)
  6. Re: proper way to check if a container is empty? (Paul Fowler 2000)
  7. proper way to check if a container is empty? (John Butler 2000)
>The best way is to do this: > >[showif [url][NIS][/URL]=%5BNIS%5D] > [math show=f]NIS=0[/math] >[/showif] > >in general, because if it's possible that a variable may have user input, >they may be putting in characters that are comparison operators (like ><,>,=,!) that could mess up statement. This would resolve those problems.In general this is true, but you can take advantage of the left-to-right parsing of the [showif] context this way:[ShowIf =[NIS]](Notice there's only one space after the ShowIf) this reads as show if 'nothing' equals the value of the [NIS] variableNow I should also point out that this is very different from checking if a variable is undefined. It's one thing to say that a variable has been defined, and it has a value of , the empty string. It's another thing entirely to say that a variable has not been defined at all, and it has no value whatsoever.Technical Support ********************************** Smith Micro, Internet Solutions Div | Formerly, Pacific Coast Software 16855 West Bernardo Drive | ------------------------- Suite 380 | eCommerce (WebCatalog) San Diego, CA 92127 | Software & Site Development 858.675.1106 | http://www.smithmicro.com 858.675.0372 (fax) **********************************------------------------------------------------------------- Brought to you by CommuniGate Pro - The Buzz Word Compliant Messaging Server. To end your Mail problems go to .This message is sent to you because you are subscribed to the mailing list . To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to WebDNA Support

DOWNLOAD WEBDNA NOW!

Top Articles:

Talk List

The WebDNA community talk-list is the best place to get some help: several hundred extremely proficient programmers with an excellent knowledge of WebDNA and an excellent spirit will deliver all the tips and tricks you can imagine...

Related Readings:

WC1.6 to WC2 date formatting (1997) redirect with frames (1997) WebCat2 - [format thousands] (1997) [WebDNA] Non-numbers entered into a field that asks for a number (2008) emailer settings and control questions (1997) weird order problem in 4.5.1 (2004) FTP and [shell] (2003) What Country (2004) Sorting problem (1997) showif and cart (1997) SSL (1998) Cookies and webcat (1997) $Quit, $CloseDatabase corrections (1997) Upgrading old WebCat Database Files (1997) shipping costs (1999) Counting records (2000) Order not created error (never mind) (1997) Processing all html files through WebCat or Typhoon (1998) Testing the WebCat Email List Members (2000) 2 easy questions re: [showif] and [sendmail] (1997)