http_value
write to HTTP client or string output stream with HTML
escapes
http_value
(in val_exprany,
[in tag varchar],
[in stream any]);
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
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.
Errors
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()
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>