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Extracts an attribute of a field's position and size, or length in characters.

The field and tag parameters (as set up in the Fields dialog – see Defining fields and tags) may be used in composite field expressions. These size attributes (in units defined in the Viewing page of the Configuration dialog) are:

left, right, top, bottom	position of field's boundaries.
width, height	size of field
x, y	coordinates at which tag is found.
length	the number of characters found.

For example, if the value of the field named title is "Miss", then the composite field

{title.length}

gives the number of characters in title, i.e. "4". Arithmetic operators may be used in composite field definitions, for example
{fielda:fieldy.length+2:3}
extracts 3 characters from fielda starting at the column position given by the number of characters in fieldy plus two characters.

Extracts a range of character(s) from a named field. There are several ways of specifying the range

•

{fieldx:n}
{fieldx:-n}
The name of the field may be followed by a colon and a number specifying the position of the first character to be extracted from the field. If a positive number is given, the first character is found by counting from the left. For example, if the field value is ABCD,EFGH then:
{field:6}
extracts the field value from character 6 onwards, omitting the first 5 characters: EFGH.
If a negative number is given, the first character is found by counting from the right. For example:
{field:-4}
extracts only the last 4 characters of the field: EFGH.

•

{fieldx:n:r}
{fieldx:-n:r}
The syntax may be followed by a further colon and the number of characters to be extracted, for example
{field:4:3}
extracts 3 characters starting at the 4th character from the left: D,E and
{field:-4:3}
extracts 3 characters starting at the 4th character from the right: EFG.

•

{fieldx:n-m}
Alternatively, the range may be given by a hyphen and an end character position number. Use positive position numbers to counting from the left and negative numbers to count from the right, e.g.
{field:4-6}
extracts 3 characters ranging from the 4th to the 6th characters from the left: D,E.

•	{fieldx:n:'separator_characters'} Another option is to specify the range using a further colon and separator character(s) as a quoted string (i.e. between a pair of single or double quotes). For example {field:1:',;'} extracts from character 1 up to the first comma or semi-colon: ABCD.

Extracts the "nth" sub-string from a field.

The sub-strings must be separated by space character(s). To extract a sub-string which itself includes space character(s), the sub-string must be enclosed in a pair of single or double quotes. For example, if a field named PERSON contained the value
Mr "John Smith" 1234
then
{person[1]} would be Mr
{person[2]} would be John Smith
{person[3]} would be 1234

Extracts the "nth" line from a multi-line field.

For example, if ADDRESS were a 4-line field generated by the OCR plugin then
{ADDRESS[#2]}
would be the second line of the address.

Note

A composite field (i.e. one defined in terms of other fields) retains its value even if it uses a sub-field of a tag which does not occur on the current page. See also Setting fields file options.

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Defining a composite field