The text was updated successfully, but these errors were encountered: Maps have no orders in keys and hence they iteration is unpredictable. :I do not fully understand the internals of the change detection (like when the next tick occurs). @obscur666 thank you. I wrote a pipe, objectToIterable, for this. @vsavkin is working on a less strong dev mode, which will treat this as OK. Other operations use the same list representation. to change the order theoretically anymore. Please file a new issue if you are encountering a similar or related problem. While this may hurt migration a little bit, it forces developers down the correct path of managing their state correctly. Why so complicate to iterate over map? So what ngFor is doing, this time around, is enforcing best practices currently discovered in Angular 1 today (of managing the ViewModel in the component (container/controller/smart component) before passing it to the ngFor directive). This action has been performed automatically by a bot. to your account. but that is known). Angular's decision is based on ;). It contains an unknown number of objects of the same type. my code seems not working. Or that has not been implemented yet? Here I wrote the type object in let bigObject: BigObject
They should rather adjust the Javascript specification so Browsers officially aren't allowed to change the order theoretically anymore. Maybe with a generic interface BigObject Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Or that looping at all is problematic? https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map, https://webcake.co/object-properties-in-angular-2s-ngfor/, https://gist.github.com/amcdnl/202596c5b85cc66d7002d10bde3ab514, http://www.ecma-international.org/ecma-262/6.0/#sec-map.prototype.set, feat(core): @Volatile() decorator to allow unstable properties for change detection, ngFor with possibility of assign key value like ES6 feature, feat(core): KeyValueDiffer support for NgForOf, feat(common): new pipe to support object for ngFor, Child changed causes entire list to be recreated, Provide primitives to iterate ES6 Maps with ngFor. Read more about our automatic conversation locking policy. You're meant to refactor the behavior into a new directive for complex views such as a grid. Is iterating with *ngFor supported for ES6 Maps, or more generally, on objects implementing [Symbol.iterator()] ? How to iterate over keys of a generic object in TypeScript? Keyspipe does't get its place. With ng-repeat what you're doing is inverting control of the management of your ViewModel from your controller to the helper directives to compose behavior. You signed in with another tab or window. See http://www.ecma-international.org/ecma-262/6.0/#sec-map.prototype.set for the Map.prototype.set() function. @IsaacBorrero It has not, would you like to make a PR? This seems like a huge glitch. @mhevery sounds fair enough. @mhevery, If anyone's interested, I wrote up a blog post following the suggested Pipe solution made by @mhevery: https://webcake.co/object-properties-in-angular-2s-ngfor/, Ran into this issue, and used the solution posted somewhere since the pipe by @mhevery seem to have the same downside as here I would expect iterating throw a Map like this: and that's working (I'm seeing the list) except that I'm having an "ExpressionChangedAfterItHasBeenCheckedError" error. ngFor doesn't support Object but ng-repeat does. error thrown when using angular cdk virtual scroller, Property does not exist on type 'IntrinsicAttributes' with useFormContext and custom tag, TypeError: Cannot set properties of undefined (setting 'object'), Angular web components with custom elements error, How to convert date into this 'yyyy-MM-dd' format in angular 2, 100% working solution for TypeError: Cannot read properties of null (reading 'classList') React. http://stackoverflow.com/questions/34313743/expressionchangedafterithasbeencheckedexception-since-angular-2-beta. Just checking if the mapToIterable pipe has been added to ng2? At the minimum, I'd expect a default pipe to be available. In older posts I had found solutions using a generator within a custom Symbol.iterator function to make the large object iterable with a for..of loop. It's a very often case when you don't care about order, you just need indexes of object for direct access (to display value in "View" mode, such as {{someList[someModel.id]}}), and to show options for select, . browser sustain the key order of objects (except if you use numbers as key, By clicking Sign up for GitHub, you agree to our terms of service and Already on GitHub? And @dlinx just means that there is no need to use a pipe, it's supported by default with proper JavaScript code. You can use a better type. Only arrays and iterables are allowed in Angular-11 Application, Why is @angular/core/core has no exported member 'FactoryDeclaration'. Can I already make use of a pipe inside ng-for that would transform that map into an array for instance? So fa Issue I want to convert current data into 'yyyy-MM-dd' format in .ts file Issue I am having this header which on scroll, I want to change the background to a differ Issue I want to make 2 API calls in Parallel and then the third immediately after that. @dlinx, ironically, what you've post just proves my thought. ;). I'm not sure why the side-effect above happens with JIT. @gdi2290 I experience the same thing, it renders them but then they're gone. Shouldn't something for smooth migration be provided by the library? privacy statement. Misleading error message "Cannot find a differ supporting object '[object Object]'". How to fix Angular issue: Cannot read properties of null (reading 'cannotContainSpace'). For what it's worth, as opposed to the order of properties in an object, the order of the elements of a Map has been strictly defined from the first version of ECMAScript which introduced it. The problem is see is getting an object with properties and returning an array. I would expect to bee faster than the pipe solution but that need to bee verifyed. Note: Only a member of this blog may post a comment. Issue I have created a custom ValidationFn in angular. The problem with ng-repeat was that it allowed for both objects and map which allowed more developers to shoot themselves in the foot (more often when they are concerned with the order). Somehow I allways get the following Issue Code is: const foo = (foo: string) => { const result = [] result.push(foo) Issue with *ngFor, I cannot fetch the data from my component.ts to my component.html The Issue I installed CDK Virtual Scroller in my ionic 5.3.3 project: npm add @angular/cdk T Issue Recently I changed my custom input components to use react useFormContext instead o Issue I have a function that when calling it opens a modal from ngbModal, I have imported Issue I am trying to create a basic web component in Angular with Angular Elements. #2246 (comment). adjust the Javascript specification so Browsers officially aren't allowed But yes, in the strictest sense the pipe should make sure that it returns the same array. How do I call 2 API in parallel and the third right after that in RXJS. @jhiemer if it is a bug, then it should be filed, and fixed, rather than worked around it. Have a question about this project? Instead just used something that was suggested somewhere else, sorry can't find where. Oddly enough, the original example works in changeDetection: ON_PUSH and JitChangeDetection until ChangeDetection does another tick then it removes them. Well occasionally send you account related emails. No comments. With Angular 1, I would say no one took the time to take the next step of refactoring their behavior into components. Normally I would tend to return a new array instead of changing the keys in the existing object. @mhevery the thing is, reading through other tickets this does not seem to be a bug. angularfix. Jupp, especially when you take into consideration that all current modern browser sustain the key order of objects (except if you use numbers as key, but that is known). compiler blows up when it sees [. Is there an issue item that I can track to get status updates? Libraries and developer are used to work with objects @mhevery I apologize, but what does that mean? But it's hacky. @rolandjitsu this is kinda supported if you write it like this example, @mhevery inside of *ng-for this doesn't work var i = index; var mykey=item[0]; var value=item[1]. Not supporting this is a mistake in ng2. Or what is the current best practice to do such an iteration with ES2015 and TypeScript (2.2.2)? On Sun, Dec 20, 2015 at 6:06 PM Marc J. Schmidt notifications@github.com I need to iterate over a large object which is just typed as "object". Error trying to diff '[object Object]'. Reply to this email directly or view it on GitHub that way (especially for configurations). var item of myMap.values(); var i = index, var item of myMap.entries(); var i = index, var item of myMap.entries(); var i = index; var mykey=item[0]; var myvalue=item[1]. I am trying to iterate over Map values with the built in ng-for, but I can see that for some reason it is not working. But that's definitely a matter of taste. What's going on is that ngFor is enforcing the developer to shape the collection correctly. This Answer collected from stackoverflow and tested by AngularFix community admins, is licensed under. Is it that ordering is inconsistent, in which case, does that matter? Successfully merging a pull request may close this issue. You were describing unpredictable ordering of object keys , which is different case. #6392. which is it makes it read only. This example doesn't work with JitChangeDetection with changeDetection: ON_PUSH but the default one is fine. Some developers even go so far as to say if Angular 1 did not include ng-repeat then we wouldn't have any performance problems since developers would have to consider how to manage their collections in a view. If there are no other reasons than the perceived inconsistent ordering, considering that iterating through Maps would be very convenient, maybe another look at this could be justified? Does anybody have an idea what I am missing here? What is "not assignable to parameter of type never" error in TypeScript? and sorts the keys. @obscur666 when using your Pipe I ran into: Expression 'entity.props | values in Component@140:26' has changed after it was checked. This issue has been automatically locked due to inactivity. I think the current design is fine. This change may also hurt prototyping which was one of Angular 1's strongest strength but someone could also create a ng-repeat/orderBy/filter directive/pipes which has the same API that relied on side effects, Maps iterate in order per https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map ecmascript-6, typescript Libraries and developer are used to work with objects that way (especially for configurations). When I get an object and transform it into a array I need to return a new object, which results into the error. In the specs, you can iterate over a Map iterable with: And none of the ES5 standard for ()/for ( in ) will work with that. Does the built in ng-for actually support iterating over maps? @mhevery wrote: Jupp, especially when you take into consideration that all current modern I have trouble about a migration from ng-repeat to ngFor. It contains an unknown number of objects of the same type. As it was already said, the original question was about ES6 Map, which is ordered by its specification. Angular's decision is based on theory, but the practice tells us something different. Copyright var creditsyear = new Date();document.write(creditsyear.getFullYear()); as an 'any' type because type '{}' has no index signature". If you want to learn more about ChangeDetection that's a post by Victor Savkin. If so it is the design, I think that a solution for the migration also should be in the design. @mhevery Hi. But the TypeScript compiler keeps giving me the error "error TS7017: Element implicitly h Please let me know and I will gladly do it https://help.github.com/articles/creating-a-pull-request/, @mhevery @IsaacBorrero - here is what I am using - https://gist.github.com/amcdnl/202596c5b85cc66d7002d10bde3ab514. the output of map.keys() is an array. I did it already, but it means we multiply *2 size of list in memory and had to use more lines of code. Are there more solid approaches? @mhevery that would help a lot.