Using the npm package azure-maps-control. After the user drags around in the map. I would like to upgrade the points of intrest using a API call. For this i found multiple events. It looks like that the sourcedata event can be used. Unfortunately after dragging i need the new GPS locations. How do i retrieve those?
For your scenario you will most likely want to wait until the user has stopped moving the map before making a request to a service to retrieve custom data since doing this while the map moves would potentially generate tens of requests per second. What you will want to do is monitor the moveend event of the map by doing something like map.events.add('moveend', yourCallbackFunction). When this event fires, you can then retrieve the center position of the map using map.getCamera().center. Here is a code sample from the Azure Maps team that does all of this and a bit more: https://azuremapscodesamples.azurewebsites.net/?sample=Load%20POIs%20as%20the%20map%20moves This sample makes multiple requests when the moveend event fires as the service it calls returns a max of a 100 results at a time, and this sample steps through and pulls in additional results.
Related
This is a detailed Flux Architecture question.
Say I have a resource that gets asynchronously prepared. Let's take User Data as an example.
There are multiple different ways to get this user data - in our example it may be that it requires a few different subsequent queries to generate from the server or is stored locally as a whole.
Case 1:
User data needs sequential steps. Fire USER_DATA_1_SUCESS, USER_DATA_2_SUCCESS. Other stores listen for USER_DATA_2_SUCCESS.
Case 2:
User Data is locally available as a whole. Fire a USER_DATA_READY action.
I'm trying to figure out how to go from a linear state completion (USER_DATA_2_SUCESS) to a resource ready event (USER_DATA_READY) in the stores. I can't call USER_DATA_READY directly from the stores - I get a can't call action in the middle of dispatch error. At the same time I want granularity - I want to control the different stages of putting the data together.
I'd like to have one way to condense these calls with good design. The option I can think of is:
Add a convenience 'Ready' function in a client class that is visible to the store. Call it with a tiny timeout in the stores callback for USER_DATA_2_SUCCESS.
Can anyone suggest a better flow?
My problem is I'm making too many API requests, which I want to cut down if possible. Below I'll describe the situation:
I have three pages, all linked using ngRoute. Like this:
Page A: Teams (list of teams)
URL: "/teams"
Page B: Team Details (list of players)
URL: "/teams/team-details"
Page C: Player Details (list of player stats)
URL: "/teams/team-details/player-details"
Page A is populated by pulling an array of the teams from an API very easily using a simple $resource.query() request, and using ng-repeat to iterate through them.
Page B is populated by calling an html template and populating specific fields with values from a separate API request to the /team-details endpoint, taking the team_id value from the clicked element on Page A.
Page C (as with page B) takes a player_id from the clicked player on Page B and calls the /player-details endpoint using that value. This is yet another separate request.
This all works fine, but as you can imagine, a single user could quite easily rack up in excess of 100 API requests within an hour.
I have a request limit of 1000/hour, so if a mere 10 users are online at the same time, it could easily exceed my limit and shut down my API.
If I could access the API as one single master endpoint that outputted all data and subdata in one set, then that would solve my problem, but since I need to request separate endpoints I can't see how to do this.
Is there a better way to approach this? Or are these excessive API requests the only way?
Any help would be appreciated.
As far as I can see, Your model looks suitable for the application and meets how an API-driven application should work...
However, One potential cut-down you could make is to cache some of the results locally. i.e. store a local version of some of the data that is unlikely to change within a session. For example, If the number of teams is unlikely to change, then store the results of 1 API request locally and use that instead of recalling data from your API.
Following on from this route, you could choose to only update certain data after a certain time period. So, if a user has looked at some team-details then refuse to update this data for the next 10-20minutes. However, this does again depend how time-sensitive your data is.
We need to run some operation on our Firebase DB and manipulate data after certain input is given by user from the Mobile Device modifying a flag.
Currently we are using on() to listen to particular flag in each users node. We are running this listener from a Nodejs server hosted on Heruku.
If we plan to have 100 thousand users we will have 100 thousand listener. One listener for each users flag which is waiting to be manipulated by user on the Mobile device.
Is this a good design in terms of Firebase?
Ideally we can create a REST API which is called by users and then on the Node JS server we can manipulate the data.
What is the best way to run background operation on Data on Firebase based on user input?
We were using Parse earlier and it was easy to achieve this using Parse Cloud code. With Firebase we are having issues because of this.
If we plan to have 100 thousand users we will have 100 thousand listener. One listener for each users flag which is waiting to be manipulated by user on the Mobile device.
This sounds like a bad data design. While it is definitely possible to listen for changes to hundreds of thousands of items, it shouldn't require hundreds of thousands listeners.
My guess (because you didn't include a snippet of your JSON) is that you have a structure similar to this:
users
$uid
name: "user6155746"
flag: "no"
And you're attaching a listener in just the flag of each user with something like:
ref.child('users').on('child_added', function(userSnapshot) {
userSnapshot.ref().child('flag').on('value', function(flagSnapshot) {
console.log('the flag changed to '+flagSnapshot.val());
});
})
In code this is simple, in practice you'll have a hard time managing the "flag listeners". When will you remove them? Do you keep a list of them?
All of these things become a list simpler if you isolate the information that you're interested in in the JSON tree:
users
$uid
name: "user6155746"
userFlags
$uid: "no"
Now you can just listen on userFlags to see if the flag of any user has changed:
ref.child('userFlags').on('child_changed', function(userSnapshot) {
console.log('Flag of user '+userSnapshot.key()+' changed to '+userSnapshot.val());
});
With this you have a single listener, monitoring the flag of potentially hundreds of thousands of users.
I am developing a WPF application on an Intel Ultrabook. As the Ultrabook already includes GPS sensors, how can I go about retrieving my current location inside my app using this sensor?
I am not able to find any sample code to get me started. Any guidance is appreciated.
See:
http://msdn.microsoft.com/en-us/library/system.device.location.geocoordinatewatcher(v=vs.100).aspx
especially the statement:
To begin accessing location data, create a GeoCoordinateWatcher and call Start or TryStart to initiate the acquisition of data from the current location provider.
The Status property can be checked to determine if data is available. If data is available, you can get the location one time from the Position property, or receive continuous location updates by handling the PositionChanged event.
My program fills an array with data from a facebook page feed but every time i go from one tab to another it wants to reload this data, is there any way i can cache this array so that it will not reload the information unless its changed?
This is exactly why your Views should not contain Service logic. Instead, your View should dispatch an event asking for the service call and your Controller (you do have one, right?) should catch that event and decide whether to act on it or not.
How do you know the data hasn't changed without reloading it?
Maybe what you need is to store the timestamp of the last service call, than measure the amount of time before executing the service call again.
Perhaps with a 5-minute timeout, if the user continuously changes tabs within 5-minutes from the last service call, the array persists previously loaded data.
After 5-minutes, if the user changes back to that tab the service call can fire, load data, than update the timestamp to prevent loading.