W3TPL/tag/get-let

About

The <get> and <let> tags are very similar, and can do similar things, even though in a way they are opposites.

• get:
  • retrieves an input or stored value and (ultimately) outputs it to the display.
    • The result is always displayed (though this can be captured and/or hidden by enclosure within another tag).
  • does not require a name= attribute.
  • is like <let> with echo and self assumed, except it doesn't store the result.
• let:
  • receives an input value and (ultimately) stores it as a variable.
    • The result is always stored in a variable (though it can also be displayed with echo).
  • requires a name= attribute.
  • if echo and self are used, is like <get> except it stores the result in a named variable.

Attributes

Each attribute belongs to a given stage, where stages are processed in this order:

• input: the primary input source for further calculations/actions is designated
• calc: zero or more operations are performed on the input, with the output of each one becoming the input for the next
  • Note that we can't really count on MediaWiki's parser preserving the order of attributes within a tag.

Both tags have these options in common.

• append (calc): append the input string to the current value
• arg= (input): name of POST field to retrieve as tag input
  • USAGE: form processing
• chr= (input): ASCII number of character to use as tag input
• copy= (input): name of another variable whose value should become the input
• lcase (calc): apply strtolower(), i.e. convert the input to lower case
  • opposite of "ucase"
• lcfirst (calc): apply lcfirst(), i.e. convert the first character of the input to lower case
  • opposite of "ucfirst"
• len= (calc): use only the first <len> characters of the input (this could probably stand some rethinking)
• parse (calc): have MediaWiki parse the input, and use the resulting string
• pre (calc): alias for "parse", for backwards compatibility
• trim (calc): apply trim()
• ucase (calc): apply strtoupper(), i.e. convert the input to upper case
  • opposite of "lcase"
• ucfirst (calc): apply ucfirst(), i.e. convert the first character of the input to upper case
  • opposite of "lcfirst"
• val= (input): value/expression to use as input