Name
http_value — write to HTTP client or string output stream with HTML escapes
Synopsis
http_value ( |
in val_expr any , |
in tag varchar , | |
in stream any ) ; |
Description
The http_value
is used to write to
an HTTP client (when in a VSP context) or a specified string output
stream. http_value
uses HTML-escapes
for characters that should be escaped according to the HTML
spec.
Parameters
val_expr
A value expression. May be any string expression. If val_expr
is an XML entity, a
serialization of the entity is written to the stream
. This is not the string value
of the XML fragment, but a serialization of the XML fragment as
text including all the markup, i.e. elements, attributes,
namespaces, text nodes, etc. To get the string value of an XML
entity, convert it to a varchar using cast
. Casting as varchar will only produce a
concatenation of the text nodes in the XML fragment, leaving out
elements, attributes, name spaces, etc.
tag
Optional. If present and is a string, the output will be
enclosed in tags named as the string content of tag
. If the expression evaluates to
0 or null, it will be ignored.
stream
Optional parameter. If omitted or is 0 and the function is
executed within a VSP context, the val_expr
will be written to the HTTP
client. If present and non-zero, val_expr
will be written to the
specified stream. If non-zero, the value must be a valid stream
obtained from function string_output
Return Values
None
Errors
Table24.45.Errors signalled by
http_value
SQLSTATE | Error Code | Error Text | Description |
---|---|---|---|
37000 | HT006 | http output function outside of http context and no stream specified: %s | occurs if called outside VSP and no string session is given |
22023 | SR066 | Unsupported case in CONVERT (<data_type_of 1st arg> -> VARCHAR): %s | if the value passed as the 1st argument can't be converted to a VARCHAR value and it's not a XML/XQUERY tree |
Using http_value()
Example24.180.HTTP output
Output of various flavours of http
. See string_output
and
string_output_string
for examples how to use
http to write to streams other than the HTTP output.
http (' % <b>') ' <b> http_value (' % <b>') % <b> http_url (' % <b>') +%25+<b> http_value (12, 'li') <li>12</li>
See Also
http
, http_url
, string_output
, http_rewrite
.