none( predicate, list, context )
Calls a rule or function that returns either true or false for each item in list by asking the question, "Do all items in this list yield false for this rule/function?" with the intent to discover if no items will yield true.
Keyword | Type | Description |
---|---|---|
|
Function, Rule, or Data Type Constructor |
Expression that returns a Boolean (true or false). |
|
Any Type Array |
List of elements that the predicate iterates through. |
|
Any Type Array |
Variable number of parameters passed directly into each predicate evaluation. |
Boolean
Use fn!functionName
or a!functionName
to reference an expression function and rule!ruleName
to reference a rule.
To use rules or functions that take more than two arguments, use the merge() function. For example, given a rule g(x, y, z)
, reduce(rule!g, i, merge({a, b, c}, {d, e, f}))
returns g(g(g(i, a, d), b, e), c, f)
.
Returns false
as soon as the returned value of an evaluation yields true; otherwise, returns true
.
Empty and null lists yield true
.
a!forEach()
cannot be used within rules used in this function.
Given a function f(x)
, none(fn!f, {a, b, c}, v)
returns not(or({f(a, v), f(b, v), f(c, v)}))
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none(
a!isNullOrEmpty,
{1, 2, null, 3, null, 4}
)
Returns false
.
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none(
a!isNullOrEmpty,
{}
)
Returns true
.
To help demonstrate how the context parameter works in looping expressions, let's look at an example.
Imagine you're building an expression that uses looping to analyze group membership in your application. You have four Group constants configured in the following ways:
Constant | Group(s) referenced | Group membership |
---|---|---|
cons!csaAdmins | CSA Administrators | user1, user3 |
cons!csaProfs | CSA Professors | user1, user2, user4, user5, user6, user7 |
cons!csaBuilding1 | CSA Building 1 | user1, user2, user3, user5, user6, user7 |
cons!allGroups | CSA Adminstrators, CSA Professors, CSA Building 1 | See above |
The following SAIL expressions reference these constants to show how context works when checking items in a list.
Note: You'll need to adapt these expression examples for your own purposes, since the examples reference constants that may not exist in your Appian environment.
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none(
a!isUserMemberOfGroup,
{"user1", "user2", "user3"},
cons!csaAdmins
)
Returns false
when user1 and user3 are members of the group referenced by cons!csaAdmins
. a!isUserMemberOfGroup
has 3 parameters: username, groups, and matchAllGroups. The none()
list corresponds to username, and the list of values provided in the context parameter are used as the next two parameters, groups & matchAllGroups.
Learn more about a!isUserMemberOfGroup().
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none(
a!isUserMemberOfGroup,
{"user1", "user2", "user3"},
{cons!allGroups, true}
)
Returns false
when user1 is a member of all the groups referenced in cons!allGroups
. a!isUserMemberOfGroup
has 3 parameters: username, groups, and matchAllGroups. The none()
list corresponds to username, and the list of values provided in the context parameter are used as the next two parameters, groups & matchAllGroups.
Learn more about a!isUserMemberOfGroup().
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none(
a!isUserMemberOfGroup,
{"user1", "user2", "user3"},
merge({cons!csaAdmins, cons!csaProfs}, {true, true})
)
Returns false
when user1 is a member of the groups referenced in cons!csaAdmins
and cons!csaProfs
. The merge function maps the list values to the correct parameters in this example.
Learn more about a!isUserMemberOfGroup().
In this example, we will use a helper rule, rule!isDateLater(value, referenceDate)
, which is defined as:
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ri!value > ri!referenceDate
Example filter:
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none(
rule!isDateLater,
{date(1950, 2, 3), date(1950, 6, 23), date(1950, 5, 2)},
date(1950, 4, 7)
)
Returns false
.
Feature | Compatibility | Note |
---|---|---|
Portals | Compatible | |
Offline Mobile | Compatible | |
Sync-Time Custom Record Fields | Compatible | Can be used to create a custom record field that only evaluates at sync time. |
Real-Time Custom Record Fields | Incompatible | Custom record fields that evaluate in real time must be configured using one or more Custom Field functions. |
Process Reports | Incompatible | Cannot be used to configure a process report. |
Process Events | Incompatible | Cannot be used to configure a process event node, such as a start event or timer event. |
none() Function