Data telltales

The content of a data telltale can be assigned to a user variable using the command

<set var=NAME telltale="N[:MODE]" />

where N is the telltale number (1 to 9) and MODE declares an optional telltale selector mode:

  • PREDATA — the telltale as it was at the beginning of the page, and before any material is set.

  • BEGIN — as for PREDATA, except that it reflects any telltale assignment made in the first paragraph, typically from a heading.

  • FIRST — the value of the first telltale actually set on the page. If the telltale isn't set on the current page, then as for predata.

  • LAST — the value of the last active telltale on the page. Is unaffected if the telltale is subsequently cleared.

  • END — as for last, except it will be empty if the telltale was cleared before page end.

  • ASSIGNED — specifies the number of times the telltale was assigned within the current page.

  • LIST — concatenate all values assigned to the telltale on the current page (see below).

If MODE is not specified, then FIRST is assumed

This form of the set command can only be used in the customisation for a header or footer mapping. An attempt to assign the value of a telltale in any other context will generate a warning.

Any tags in the computed value will be removed before the value is assigned.

The LIST mode produces a string by concatenating all values assigned on the page and inserting a separator character between each value. If no values were assigned the value is the empty string. The separator character is the character used in the command between the telltale number and the mode string. Any non-alphanumeric ASCII character other than ‘<’, ‘>’, ‘&’ or ‘^’ may be used as the separator.

The following example shows how to assign a variable with the value of the last active telltale on the page:

<set var="PartNum" telltale="1:last" />