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Difference between revisions of "IdAS String Filters"
(New page: ==Problem== While the current IFilter, IFilterAssertion (and sub-interfaces) are adequate to perform complex searches across an IdAS context, it is cumbersome to code to them. Furthermore...) |
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The following ABNF could be used to represent filters as strings. Note that I simply looked at the way today's IFilter is and extrapolated an ABNF. | The following ABNF could be used to represent filters as strings. Note that I simply looked at the way today's IFilter is and extrapolated an ABNF. | ||
| − | filter = LP filteritem RP | + | <pre> |
| − | filteritem = assertion / and / or / not | + | filter = LP filteritem RP |
| − | assertion = | + | filteritem = assertion / and / or / not |
| − | and = AMP 1*filter | + | assertion = attrpresent / |
| − | or = BAR 1*filter | + | attreq / |
| − | not = EXC filter | + | attrge / |
| − | + | attrle / | |
| − | resource = | + | attrsub / |
| − | value = | + | eideq / |
| + | etypeeq | ||
| + | and = AMP 1*filter | ||
| + | or = BAR 1*filter | ||
| + | not = EXC filter | ||
| + | attrpresent = "a:" resource ; matches when an entity has an attribute (named by resource) present | ||
| + | attreq = "a=:" resource SP value ; matches when an entity has an attribute (named by resource) with a value equal to value | ||
| + | attrge = "a>=:" resource SP value ; matches when an entity has an attribute (named by resource) with a value greater or equal to value | ||
| + | attrle = "a<=:" resource SP value ; matches when an entity has an attribute (named by resource) with a value less or equal to value | ||
| + | attrsub = "a*:" resource SP value ; matches when an entity has an attribute (named by resource) with a value containing a substring of value | ||
| + | attrext = "a(" matchrule ")" resource SP value ; matches when an entity has an attribute (named by resource) with a value matching value using the specified matchrule | ||
| + | eideq = "eid=:" SP entityid ; matches when an entity has the id specified in entityid | ||
| + | etypeeq = "etype=:" SP resource ; matches when an entity's type matches that specified in resource | ||
| + | resource = URI ; typically specifies an attribute ID or entity type | ||
| + | value = ; TODO: occurrences of RP must be escaped in values | ||
| + | ; TODO: how are complex attr's represented? | ||
| + | ; TODO: how are attr's on values represented? | ||
| + | matchrule = URI ; specifies a matching rule | ||
| + | LP = %x28 ; left paren ("(") | ||
| + | RP = %x29 ; right paren (")") | ||
| + | SP = %x20 ; space (" ") | ||
| + | AMP = %x26 ; ampersand ("&") | ||
| + | BAR = %x7C ; vertical bar or pipe ("|") | ||
| + | EXC = %x21 ; exclamation mark ("!") | ||
| + | </pre> | ||
| + | |||
| + | ====Examples==== | ||
| + | Match for any entity with a telephone number of 888-555-1212 or 888-123-4567 | ||
| + | <pre> | ||
| + | (&(a=:http://example.org/attrs/phonenumber 888-555-1212)(a=:http://example.org/attrs/phonenumber 888-123-4567)) | ||
| + | </pre> | ||
| + | Match entities who's first name is Robert, Bob, or Bobby | ||
| + | <pre> | ||
| + | (a(http://example.org/matchrules/nicknames):http://example.org/attributes/givenname Robert) | ||
| + | </pre> | ||
===XML=== | ===XML=== | ||
Latest revision as of 14:03, 30 July 2008
Contents
Problem
While the current IFilter, IFilterAssertion (and sub-interfaces) are adequate to perform complex searches across an IdAS context, it is cumbersome to code to them. Furthermore, there is currently no way to represent a filter using a string such that it could be passed easily across a wire protocol
Proposals
ABNF
The following ABNF could be used to represent filters as strings. Note that I simply looked at the way today's IFilter is and extrapolated an ABNF.
filter = LP filteritem RP
filteritem = assertion / and / or / not
assertion = attrpresent /
attreq /
attrge /
attrle /
attrsub /
eideq /
etypeeq
and = AMP 1*filter
or = BAR 1*filter
not = EXC filter
attrpresent = "a:" resource ; matches when an entity has an attribute (named by resource) present
attreq = "a=:" resource SP value ; matches when an entity has an attribute (named by resource) with a value equal to value
attrge = "a>=:" resource SP value ; matches when an entity has an attribute (named by resource) with a value greater or equal to value
attrle = "a<=:" resource SP value ; matches when an entity has an attribute (named by resource) with a value less or equal to value
attrsub = "a*:" resource SP value ; matches when an entity has an attribute (named by resource) with a value containing a substring of value
attrext = "a(" matchrule ")" resource SP value ; matches when an entity has an attribute (named by resource) with a value matching value using the specified matchrule
eideq = "eid=:" SP entityid ; matches when an entity has the id specified in entityid
etypeeq = "etype=:" SP resource ; matches when an entity's type matches that specified in resource
resource = URI ; typically specifies an attribute ID or entity type
value = ; TODO: occurrences of RP must be escaped in values
; TODO: how are complex attr's represented?
; TODO: how are attr's on values represented?
matchrule = URI ; specifies a matching rule
LP = %x28 ; left paren ("(")
RP = %x29 ; right paren (")")
SP = %x20 ; space (" ")
AMP = %x26 ; ampersand ("&")
BAR = %x7C ; vertical bar or pipe ("|")
EXC = %x21 ; exclamation mark ("!")
Examples
Match for any entity with a telephone number of 888-555-1212 or 888-123-4567
(&(a=:http://example.org/attrs/phonenumber 888-555-1212)(a=:http://example.org/attrs/phonenumber 888-123-4567))
Match entities who's first name is Robert, Bob, or Bobby
(a(http://example.org/matchrules/nicknames):http://example.org/attributes/givenname Robert)