Apologies if I've just managed to miss it in the docs, but I can't find a way to do this in Apollo Client.
I've read about query batching, but this in fact the opposite of what I want to do. I want my queries sent as separate isolated queries.
Happy to expand on details if needed, but I think the title says it all.
so, my solution has been to create a new component that
returns null (i.e. renders nothing)
runs a useQuery and puts the result into an array (who's setter is passed in from the parent)
This new component sits inside a loop that iterates all my different variable sets that I want to fire the query with.
Related
I want to perform an action based to the result of an asynchronous NGXS action.
In a Angular frontend app I'm using NGXS for state management. Some of the actions involve talking to a backend via REST calls. Those actions are implemented as asynchronous actions, with the reducer functions in my state classes returning an Observable.
What I'm looking for is a way to get hands on the result of the backend call, to be able to perform some action.
One use case I'm trying to implement is navigation to just created objects: Business objects are created in the frontend (Angular) app with a couple of domain properties. They get persisted in the backend, and as a result an ID for this object is created and returned to the frontend, and incorporated into the NGXS store. As a direct response to this, I'd like to navigate to a detail view for the new object. To do so, I need
(a) the information that the call has been returned successful, and
(b) the answer from the backend (the ID in this case).
Another slightly more complicated use case is the assignment of a number of tags to an business object. The tags are entities by themselfes, and have an ID each. In the UI, the user can either pick existing or add new tags. Either way, multiple tags can be added in a single step in the UI, which means I have to
call the backend for each new tag to create the ID
after all missing tags are created, update the business object with the list of tag IDs
In general, there are use cases in the frontend that depend on the result of a backend call, and there is no clean way to find this result in the store (although it's in there)
I know I can subscribe to the Observable returned from the store's dispatch method (as shown in asynchronous actions).
I also know about action handlers. In both cases I can attach code to the event of an action finished, but neither option enables me to get the result of the backend call. In the fist case, the Observable carries the whole store, while in the latter case I get the original Action, which is unfortunately missing the essential information (the ID).
The part you're missing here are selectors. Dispatching actions is not supposed to give you back a result. The only purpose of the Observable returned by store.dispatch() is to tell you when the action's handlers are done.
To get to the data returned by your calls to the backend, you have to patch the state inside your action handler. And then, outside of your state, you can access the data using store.select() or store.selectSnapshot() depending on what you need. Your state class should look somewhat like this (untested):
#State()
export class SampleState {
#Selector(SampleState)
sampleSelector(state) {
return state.sampleObject;
}
#Action(SampleAction)
sampleAction(ctx: StateContext<any>, action: sampleAction) {
return sampleBackendCall(/* ... */).pipe(
tap((result) => {
ctx.patchState({ sampleObject: result });
})
);
}
}
Now you can access this result where ever you need using the Store. For the use case of navigating to an element after its creation, you can combine a subscription to store.dispatch() with a store.selectSnapshot() like this:
store.dispatch(new SampleAction()).subscribe(() => {
navigateTo(store.selectSnapshot(SampleState.sampleSelector));
});
Note that in this easy case a selectSnapshot is perfectly fine, as we only want to get the value we just finished writing into the state. In most cases though, you will want to use store.select() or the #Select() decorator because they return Observables which enable you to also correctly display changes in your state.
That said, I'd like to add that if saving data inside the state is not necessary for you at all, then probably NGXS is the wrong library for you in the first place and you could as well just use an ordinary angular service directly returning the result of the backend call, like suggested in the comments.
I'm using Google Data Studio to visualize results from various queries (from different tables within the same BigQuery-database).
For this reason, I created and use multiple data-sources-connectors. Each one of them has a SQL query included and makes use of an defined input parameter (which can be changed by report editors) - called "userid". It is the same id for all queries and resulting charts.
However, when I click "Manage URL parameters", I'm not allowed to use the same URL parameter for more than one data source (instead they are called ds0, ds1, ds2 etc - although they all end up being used as "userid").
If I add a data source under File - Report Settings, a new field "userid" appears, which I can alter - this will update ALL charts in the report with the very same userid (as expected). This works, but I do want to make use of an url which delivers an report with all updated queries depending on ONE userid.
Therefore, I guess I'm overseeing something - it should be possible to just use one query parameter to update the same "userid" for all queries in all data connectors? Or have I overlooked the possibility to fire multiple queries within one data source connector? Or is it expected to create a looong url full of redundant query parameters in this case?
I'm curious for your input!
Best regards :)
There does not seem to be any good solution for this.
For now the best workaround seems to be to just repeat the parameter multiple times -- it's ugly but it works. For example, use the URL parameter mapping screen to call the parameter u1, u2, etc., and then just pass all of them:
?params={"u1":"foo","u2":"foo"}
(URL encoded of course)
The ugliness is mostly for us developers: it violates our sense of DRY and clean code, and makes the URL much longer than it needs to be. However, most people don't care or know about the URL parameters so its irrelevant to them.
The bigger downside is that when the URL is distributed to clients (bookmarks, mobile apps), every time new data sources are added that require the same URL parameters, a new URL has to be distributed to clients for no good reason. A workaround for this is to build the URL dynamically via a simple redirector function.
This issue https://issuetracker.google.com/issues/180705297 is a feature request to implement this capability.
If you group the elements that you want to control with the same parameter (select and then shift G) then it will give you options to select the data source and the params box to apply to the group.
I am having someone create a bunch of templates (themes) for a website, and want to keep data passed to the views flexible.
For example, with the users in the system I want to be able to supply the top x users and the most recent x users. In my controller I don't want to pass this data to the view, because he might just need the top 5 users and I am querying the top 10 - or worse, I might only get the top 5 and he wants the top 10.
I am thinking there would be two ways to do this.
1 - A view "helpers" file, which could contain functions like. getTopUsers($count) and getNewestUsers($count) which would do the model / repo call.
2 - Create a view presenter to keep these extra functions. I've had a look and there seems to be two main presenter packages - https://github.com/ShawnMcCool/laravel-auto-presenter and https://github.com/laracasts/Presenter
Maybe there is a better way?
There could be half a dozen of these, for various models...
I would pop some client side code into your views and access a route to a controller action (which returns JSON by default) and conditionally add that particular snippet into your view (via a variable passed to the view that determines if the person is logged in). Then you can apply an auth filter to your route to protect it.
Note: with this approach you can pass url parameters to your action. This means you can tell your controller to limit your results more easily.
This is a very interesting question, my friend. What I can think of is the following
1) cheap way, just query 10 or whichever the biggest number, and then pass a variable $count to the view or let view pass a variable to the sub view
2) api call, if you'd like to do AJAX call, then as others suggested, you could just design a new route, getData?count=5.
Normally it's not easy to meet all requirements, and practically speaking in the prototype stage, it'll be more cost-effective to write fixed function like getData5, and getData10, or just make two pages :) it'll be a lot faster than coming up another new architecture design and then realize in the end nobody really uses them.
I'm running in to an issue in that I need to get one value in a cucumber statement, and then give that value to another statement.
Specifically I am getting a JSON object from one page (where that object gets sent to an api endpoint as a preference) and then using information out of that after I query the api, which happens in a completely separate step.
I am suspecting that I have to write the value somewhere, and then pull that value when the step that needs it comes up, but I'm kind of at a loss for doing that as well.
I can provide any further needed details, thanks for any help!
Definitely a rookie question - to which the answer is to use instance variables - #variable_name = get_method in the helper method your step calls.
I'm making a pretty standard AJAXy (well, no XML actually) web page. The browser makes a bunch of API queries that return JSON to run the site. The problem is, I need to add to the API interface each time the page needs to do something new. The new API interface is usually little more than a database query followed by mapping the returned objects to JSON.
What I'd like to do is to get rid of all that server-side duplication and just have the page make database requests itself (using the model interface), but in a way that is safe (i.e. just read only ones). I think this would amount to an interface for constructing Q objects using JSON or something like that, and then send that up to the server, run the query, and return the results. Before I go making my own half-broken architecture for this, I'm wondering if this has already been done well. Also, is this even the best way to go about eliminating this duplication?
Thanks
Search multiple fields of django model without 3rd party app
Django SQL OR via filter() & Q(): Dynamic?
Generate a django queryset based on dict keys
Just replace with operator.and_ where appropriate.