webMathematica`

MSPBlock

MSPBlock[{vari,…}, body]

interpret the argument variables and replace in the body

MSPBlock[{vari,…}, body, defvalue]

if any of the variables do not have values, defvalue is returned

Details

  • This is one of the key ways to work with variables from the HTTP request.
  • MSPBlock takes each of the variables var_i, interprets them, and then replaces any occurrences in body with the interpreted value.
  • If any variables do not have values, an empty string is returned.
  • The following exceptions can be thrown by MSPBlock.
  • MSPException["ParseError"]if the value cannot be interpreted by Mathematica
    MSPException["SecurityError"]if the value does not pass the security test
    MSPException["ValueError"]if the value is not a string, this indicates a programmatic error by the page author
    MSPException["VariableError"]if the variable is not a Mathematica symbol, this indicates a programmatic error by the page author

Examples

Basic Examples  (1)

You can simulate how the function works by installing and loading the package and setting the security content.

Here the variable $$var is assigned to the value "5+7"; note that the value is a string.

When MSPBlock evaluates, all occurrences of $$var are replaced by its interpreted value.

If the input value cannot be interpreted, an MSPException is thrown.

If the input value does not pass the security test, an MSPException is thrown.

Input can also be given in MathML.