4.30. flag

Controls Interchange flags. For example, flags affect database access and transactions for those databases able to support these features. See also the [tag] tag.

4.30.1. Summary

    [flag type]

Parameters	Description	Default
build	Forces build of static Interchange page specified by the name attribute	DEFAULT_VALUE
checkhtml		DEFAULT_VALUE
commit	Attempts to commit transactions	DEFAULT_VALUE
flag	Alias for type	DEFAULT_VALUE
name	Alias for type	DEFAULT_VALUE
read	Flags the table read-only	DEFAULT_VALUE
rollback	Attempts to rollback transactions	DEFAULT_VALUE
show	Normally, the [flag] tag returns nothing to the page. Setting 'show=1' causes the tag to return status, if any.	DEFAULT_VALUE
table	Alias for tables	DEFAULT_VALUE
tables	The name of the table to flag 'table' is an alias	DEFAULT_VALUE
transactions	Reopens the database in transactions mode if Safe.pm is not active (e.g., in a global subroutine, usertag or [perl global=1] tag). The limitation exists because it is not possible to reopen a database within Safe.pm.	DEFAULT_VALUE
type		DEFAULT_VALUE
value	The boolean value of the flag	DEFAULT_VALUE
write	Flags the table writable by default (or read-only if you also set the value=0 attribute)	DEFAULT_VALUE

Attributes	Default
interpolate (reparse)	No

Other_Characteristics
Invalidates cache	YES
Container tag	No
Has Subtags	No
Nests	Yes

Tag expansion example:

    [flag type]
---
    TODO: (tag result)

ASP-like Perl call:

   $Tag->flag(  { type => VALUE_type
}, $body  );

or similarly with positional parameters,

    $Tag->flag(type, $attribute_hash_reference, $body);

4.30.2. Description

The flag tag controls database access and transactions.

If a DBM-based database is to be modified, it must be flagged writable on the page calling the write tag.

For example, you can call

    [flag type=write value=1 table=products]

to mark the products DBM database writable. This must be done before ANY access to that table.

Note that SQL databases are always writable if allowed by the SQL database itself, and in-memory databases will never be written.

Using [flag build] forces static build of a page, even if it contains dynamic elements.

4.30.2.1. build

Forces build of static Interchange page specified by the name attribute

4.30.2.2. checkhtml

4.30.2.3. commit

Attempts to commit transactions

4.30.2.4. read

Flags the table read-only

4.30.2.5. rollback

Attempts to rollback transactions

4.30.2.6. show

Normally, the [flag] tag returns nothing to the page. Setting 'show=1' causes the tag to return status, if any.

4.30.2.7. tables

The name of the table to flag

• 'table' is an alias

4.30.2.8. transactions

Reopens the database in transactions mode if Safe.pm is not active (e.g., in a global subroutine, usertag or [perl global=1] tag). The limitation exists because it is not possible to reopen a database within Safe.pm.

4.30.2.9. type

4.30.2.10. value

The boolean value of the flag

4.30.2.11. write

Flags the table writable by default (or read-only if you also set the value=0 attribute)