Since developers are allowed to customize start/end interpolation
strings, but third-party directive creators don't know about these
customizations, we should standardize on {{ }} in templates of
reusable (third-party) directives. During the compilation, these
templates are then denormalized to use whatever the custom
start/end symbol is, effectively translating the template into the
syntax of the runtime environment.
This addresses an issue raised at http://goo.gl/e8VPV
Existing code should not be affected by this change since project
that do use custom interpolation markers are not expected to use
{{ }} in existing directive templates.
Changed the isolate scope binding options to:
- @attr - attribute binding (including interpolation)
- =model - by-directional model binding
- &expr - expression execution binding
This change simplifies the terminology as well as
number of choices available to the developer. It
also supports local name aliasing from the parent.
BREAKING CHANGE: isolate scope bindings definition has changed and
the inject option for the directive controller injection was removed.
To migrate the code follow the example below:
Before:
scope: {
myAttr: 'attribute',
myBind: 'bind',
myExpression: 'expression',
myEval: 'evaluate',
myAccessor: 'accessor'
}
After:
scope: {
myAttr: '@',
myBind: '@',
myExpression: '&',
// myEval - usually not useful, but in cases where the expression is assignable, you can use '='
myAccessor: '=' // in directive's template change myAccessor() to myAccessor
}
The removed `inject` wasn't generaly useful for directives so there should be no code using it.
attr.$observe used to call function only if there was interpolation
on that attribute. We now call the observation function all the time
but we only save the reference to it if interpolation is present.
This stuff was never documented and is an accidental leftover from the time
when the compiler was rewritten.
If any code depends on this, it should be rewritten to use ngTransclude directive
intead.
