From fdeb0a971742791c88e077dc3cbb34ea0f9c33c0 Mon Sep 17 00:00:00 2001 From: Ms2ger Date: Mon, 25 Mar 2019 10:47:19 +0100 Subject: [PATCH] Remove unused callback interface functionality Fixes #661. --- index.bs | 196 +++++++------------------------------------------------ 1 file changed, 25 insertions(+), 171 deletions(-) diff --git a/index.bs b/index.bs index 1b73bf17..3f5beff7 100644 --- a/index.bs +++ b/index.bs @@ -931,21 +931,23 @@ Note: See also the similarly named [=callback function=] definition. [=Callback interfaces=] must not [=interface/inherit=] -from any non-callback interfaces, and non-callback interfaces must not +from any interfaces, and non-callback interfaces must not inherit from any callback interfaces. Callback interfaces must not [=include=] any [=interface mixins=]. -[=Static attributes=] and +[=Regular attributes=], +[=static attributes=] and [=static operations=] must not be defined on a [=callback interface=]. +[=Callback interfaces=] must define exactly one [=regular operation=]. +
Specification authors should not define [=callback interfaces=] - that have only a single [=operation=], unless required to describe the requirements of existing APIs. - Instead, a [=callback function=] should be used. + Instead, a [=callback function=] or a [=dictionary=] should be used. The definition of EventListener as a [=callback interface=] @@ -959,68 +961,6 @@ be defined on a [=callback interface=].
-

- Perhaps this warning shouldn't apply if you are planning to extend the callback - interface in the future. That's probably a good reason to start off with a single - operation callback interface. -

- -

- I think we need to support operations not being implemented on a given - object implementing a callback interface. If specs extending an existing - callback interface, we probably want to be able to avoid calling the - operations that aren't implemented (and having some default behavior instead). - So we should perhaps define a term that means whether the operation is - implemented, which in the ECMAScript binding would correspond to checking - for the property's existence. -

- -
- - Specification authors wanting to define APIs that take ECMAScript objects - as “property bag” like function arguments are suggested to use - [=dictionaries=] rather than - [=callback interfaces=]. - - For example, instead of this: - - 
-        callback interface Options {
-          attribute DOMString? option1;
-          attribute DOMString? option2;
-          attribute long? option3;
-        };
-
-        [Exposed=Window]
-        interface A {
-          void doTask(DOMString type, Options options);
-        };
-
- - to be used like this: - - 
-        var a = getA();  // Get an instance of A.
-
-        a.doTask("something", { option1: "banana", option3: 100 });
-
- - instead write the following: - - 
-        dictionary Options {
-          DOMString? option1;
-          DOMString? option2;
-          long? option3;
-        };
-
-        [Exposed=Window]
-        interface A {
-          void doTask(DOMString type, optional Options options);
-        };
-
-
- The IDL for interfaces can be split into multiple parts by using partial interface definitions (matching partial PartialInterfaceRest). @@ -1524,7 +1464,7 @@ and summarized in the following informative table: [=Regular attributes=] ● - ● + ● Only [=read only=] attributes @@ -3608,7 +3548,7 @@ the following algorithm returns true. 
             callback interface CBIface {
-                attribute DOMString attr1;
+                void handle();
             };
 
             [Exposed=Window]
@@ -9669,7 +9609,7 @@ must not be used on a
 
 The [{{PutForwards}}] extended attribute
 must not be used on an attribute declared on
-a [=callback interface=] or [=namespace=].
+a [=namespace=].
 
 See the Attributes section for how
 [{{PutForwards}}]
@@ -9743,10 +9683,6 @@ The [{{Replaceable}}] extended attribute
 must not be used on a
 [=static attribute=].
 
-The [{{Replaceable}}] extended attribute
-must not be used on an attribute declared on
-a [=callback interface=].
-
 The [{{Replaceable}}] extended attribute
 must not be used on an attribute declared on
 a [=namespace=].
@@ -12881,16 +12817,11 @@ implemented in script by any ECMAScript object.
 The following cases explain how a [=callback interface=]'s [=operation=] is invoked on a given
 object:
 
-: If the interface is a [=single operation callback interface=]:
-::  *   If the object is [=ECMAScript/callable=], then the implementation of the operation is the
-        callable object itself.
-    *   Otherwise, the implementation of the operation is calling the result of invoking the
-        internal \[[Get]] method on the object with a property name that is the [=identifier=] of
-        the operation.
-: If the interface is not a [=single operation callback interface=]:
-::  For each operation declared on the interface with a given [=identifier=], the implementation
-    is calling the result of invoking \[[Get]] on the object with a property name that is that
-    identifier.
+*   If the object is [=ECMAScript/callable=], then the implementation of the operation is the
+    callable object itself.
+*   Otherwise, the implementation of the operation is calling the result of invoking the
+    internal \[[Get]] method on the object with a property name that is the [=identifier=] of
+    the operation.
 
 Note that ECMAScript objects need not have
 properties corresponding to [=constants=]
@@ -12898,14 +12829,6 @@ on them to be considered as
 implementing [=callback interfaces=] that happen
 to have constants declared on them.
 
-A single operation callback interface is
-a [=callback interface=] that:
-
-*   is not declared to [=interface/inherit=] from another interface,
-*   has no [=attributes=], and
-*   has one or more [=regular operations=] that all have the same [=identifier=],
-    and no others.
-
 A Web IDL arguments list is a [=list=] of values each of which is either an IDL value or
 the special value “missing”, which represents a missing optional argument.
 
@@ -12947,22 +12870,17 @@ the special value “missing”, which represents a missing optional argument.
     1.  Let |stored settings| be |value|'s [=callback context=].
     1.  [=Prepare to run script=] with |relevant settings|.
     1.  [=Prepare to run a callback=] with |stored settings|.
-    1.  Determine the implementation of the operation, |X|:
-        1.  If |value|'s interface is a [=single operation callback interface=] and
-            [=!=] IsCallable(|O|) is true,
-            then set |X| to |O|.
-        1.  Otherwise:
-            1.  Let |getResult| be Get(|O|, |opName|).
-            1.  If |getResult| is an [=abrupt completion=], set |completion|
-                to |getResult| and jump to the step labeled return.
-            1.  Set |X| to |getResult|.\[[Value]].
-    1.  If [=!=] IsCallable(|X|) is false,
-        then set |completion| to a new Completion{\[[Type]]: throw, \[[Value]]: a
-        newly created {{ECMAScript/TypeError}} object, \[[Target]]: empty}, and jump
-        to the step labeled return.
-    1.  If |value|'s interface is not a [=single operation callback interface=],
-        or if [=!=] IsCallable(|O|) is false,
-        set |thisArg| to |O| (overriding the provided value).
+    1.  Let |X| be |O|.
+    1.  If [=!=] IsCallable(|O|) is false, then:
+        1.  Let |getResult| be Get(|O|, |opName|).
+        1.  If |getResult| is an [=abrupt completion=], set |completion|
+            to |getResult| and jump to the step labeled return.
+        1.  Set |X| to |getResult|.\[[Value]].
+        1.  If [=!=] IsCallable(|X|) is false,
+            then set |completion| to a new Completion{\[[Type]]: throw, \[[Value]]: a
+            newly created {{ECMAScript/TypeError}} object, \[[Target]]: empty}, and jump
+            to the step labeled return.
+        1.  Set |thisArg| to |O| (overriding the provided value).
     1.  Let |esArgs| be the result of [=Web IDL arguments list/converting=] |args| to an ECMAScript
         arguments list. If this throws an exception, set |completion| to the completion value
         representing the thrown exception and jump to the step labeled
@@ -12986,70 +12904,6 @@ the special value “missing”, which represents a missing optional argument.
             |rejectedPromise| to the operation's return type.
 
 
-

-
-    To get a user object's attribute value,
-    given a [=Interface types|callback interface type=] value |object| and
-    attribute name |attributeName|, perform the following steps.
-    These steps will either return an IDL value or throw an exception.
-
-    1.  Let |completion| be an uninitialized variable.
-    1.  Let |O| be the ECMAScript object corresponding to |object|.
-    1.  Let |realm| be |O|'s [=associated Realm=].
-    1.  Let |relevant settings| be |realm|'s [=Realm/settings object=].
-    1.  Let |stored settings| be |object|'s [=callback context=].
-    1.  [=Prepare to run script=] with |relevant settings|.
-    1.  [=Prepare to run a callback=] with |stored settings|.
-    1.  Let |getResult| be Get(|O|, |attributeName|).
-    1.  If |getResult| is an [=abrupt completion=], set |completion| to
-        |getResult| and jump to the step labeled return.
-    1.  Set |completion| to the result of
-        [=converted to an IDL value|converting=] |getResult|.\[[Value]] to
-        an IDL value of the same type as the attribute's type.
-    1.  Return: at this
-        point |completion| will be set to an ECMAScript completion value.
-        1.  [=Clean up after running a callback=] with |stored settings|.
-        1.  [=Clean up after running script=] with |relevant settings|.
-        1.  If |completion| is a normal completion, return |completion|.
-        1.  If |completion| is an [=abrupt completion=] and the attribute's type is
-            not a [=promise type=], return |completion|.
-        1.  Let |rejectedPromise| be [=!=] Call({{%Promise_reject%}},
-            {{%Promise%}}, «|completion|.\[[Value]]»).
-        1.  Return the result of [=converted to an IDL value|converting=]
-            |rejectedPromise| to the attribute's type.
-

-
-

-
-    To set a user object's attribute value,
-    given a [=Interface types|callback interface type=] value |object|,
-    attribute name |attributeName|, and IDL value |value|,
-    perform the following steps.
-    These steps will not return anything, but could throw an exception.
-
-    1.  Let |completion| be an uninitialized variable.
-    1.  Let |O| be the ECMAScript object corresponding to |object|.
-    1.  Let |realm| be |O|'s [=associated Realm=].
-    1.  Let |relevant settings| be |realm|'s [=Realm/settings object=].
-    1.  Let |stored settings| be |object|'s [=callback context=].
-    1.  [=Prepare to run script=] with |relevant settings|.
-    1.  [=Prepare to run a callback=] with |stored settings|.
-    1.  Let |convertResult| be the result of
-        [=converted to an ECMAScript value|converting=] |value|
-        to an ECMAScript value.
-    1.  If |convertResult| is an [=abrupt completion=], set |completion| to
-        |convertResult| and jump to the step labeled return.
-    1.  Set |completion| to Set(|O|, |attributeName|,
-        |convertResult|.\[[Value]], true).
-    1.  Return: at this
-        point |completion| will be set to an ECMAScript completion value, which is
-        either an [=abrupt completion=] or a normal completion for the value true (as returned by Set).
-        1.  [=Clean up after running a callback=] with |stored settings|.
-        1.  [=Clean up after running script=] with |relevant settings|.
-        1.  If |completion| is an [=abrupt completion=], return |completion|.
-        1.  Return NormalCompletion({{void}}).
-

-
 
 
Invoking callback functions