ng-repeat fails to show items when filter text is null (1.3.15)

[RickStrahl]

Upgraded to 1.3.15 today in one of my apps and found that an ng-repeat option list with a filter no longer displayed any items. It appears the problem is due to the fact the initial string filter value is null - if I change the initial value to an empty string it works.

// intial view model value that doesn't work
vm.searchText = null;
vm.resourceList = [ 
   { ResourceId: "Add", Style=null },
   { ResourceId: "Add_Title", Style="margin-left: 10px" },
   ...
];

Then in the HTML to bind:

<option ng-repeat="resource in view.resourceList | filter:view.searchText"
        value="{{resource.ResourceId}}"
        style="{{resource.Style}}">
    {{resource.ResourceId}}
</option>

If the intial value of searchText is null the list will not display any items. If the initial value is an empty string (""), however it works fine. This is a breaking change from 1.3.14 where this worked. If by design this should probably go into the breaking change list.

However I think null should be treated like an empty string for search filters I believe so I'd call this a bug...

[pkozlowski-opensource]

I believe that it was fixed in master via b5002ab. @gkalpak @petebacondarwin shell we back-port it to 1.3.x?

[gkalpak]

Since this is a regression introduced in 1.3.15, I think it should be back-ported.

[petebacondarwin]

Thanks @gkalpak - I think that closes this issue.

[gkalpak]

@petebacondarwin, I have submitted the PR, but it isn't merged yet. (So, technically this isn't solved (yet).)

[RickStrahl]

Thanks all for looking into this. Much appreciated!

[issoft-nsiniakevich]

@gkalpak How can I do "not null" check in this way?
{ someProperty: !null} doesn't seems to be working
http://plnkr.co/edit/Apv2qqTGaWQMSpjywnyX?p=preview

{ someProperty: ''} it's working, but I don't think that it's very obvious not null check

in the 1.3.15 { someProperty: '!null'} worked fine

[gkalpak]

@issoft-nsiniakevich, I am afraid you should either use {someProp: ''} (which means "match against any primitive value (except for null/undefined)") or use a custom filter function.
The 1.3.15 behaviour was a regression (introduced after a refactoring in 1.3.6), so 1.3.16 re-instated the "original" behaviour.

[TheSharpieOne]

Also worth noting that I have been tracking this ability in an SO answer. You can see there that this has changed over the different versions and while it appears that {someProp: ''} is recommended, {someProp: '!!'} will work as well and has support/worked back through 1.1 (breaking 1.3.6 through 1.3.15 as noted as regression).

[Nazirkulov]

Hi dear ang developers! $filter('filter')(array, {property: "!null"}) or
$filter('filter')(array, {property: !null}) does not work . It work for double not ("!!")
$filter('filter')(array, {property: "!!"}) - its norm ?

[petebacondarwin]

$filter('filter')(array, {property: "!null"}) is saying that the array item must not contain the text "null", rather than the property not being null.

$filter('filter')(array, {property: !null}) is equivalent to $filter('filter')(array, {property: true}) since the !null expression will be evaluated before being pass to the filter.

It seems that "!!" is the best approach to take in this scenario.

[gkalpak]

To expand a bit on what @petebacondarwin said:

In the current version (which hasn't changed iirc since 1.4.x), {prop: ''} (which is equivalent to {prop: '!!'} - this is a bug in filterFilter, but ¯\_(ツ)_/¯ ) matches all objects that have a primitive prop value except null or undefined. Similarly, {prop: '!'} matches the opposite (null, undefined, or non-primitive<sup):

const expr = {foo: ''};
filterFilter([{foo: 'bar'}, {foo: true}, {foo: 1}], expr)  //--> All match
filterFilter([{foo: null}, {foo: undefined}, {foo: {}}], expr)  //--> No match

const expr = {foo: '!'};
filterFilter([{foo: 'bar'}, {foo: true}, {foo: 1}], expr)  //--> No match
filterFilter([{foo: null}, {foo: undefined}, {foo: {}}], expr)  //--> All match

*: Objects with a custom toString() method are matched using the result of their toString().