I can't seem to find exactly what I'm looking for after a few day's worth of hunting, so if anyone has seen exactly what I'm trying to do elsewhere, I'd love a link or two.
Anyway, I'm trying to build an app to connect into an ERP system that returns user access information in JSON format via REST request using an e-mail address and password. Most users of the system only have a singular access role, so no big deal for them, but others have multiple roles. The trouble I'm having is taking these multiple access roles and adding them into a ListView where they can select the role with which they wish to use to gain access.
Trouble is, I need a display that uses two lines per selection (to properly display all user-pertinent data) and some way to record the user selection. The data useful in the background for the selection would not be displayed, as it would not mean anything to the user. I've been able to take the JSON response and map it to a custom class I designed for it without any problems (not actually all that useful, mostly only helps for discerning the results count prior to displaying multiple results to the ListView). But I can't figure out how to properly build the ListView layout and map the data to the layout. I'm having trouble understanding how to build the view and insert data into new list items.
The best I figure, if I can get the results to display in a ListView and then record the selection in the shared preferences, I'll be golden.
If the listview items being populated from some JSONArray then you could use listview.setOnItemClickListener to get the position of the selected item and match it from the array.Your question seems a little vague. Can you post some code of what you've tried so that it becomes a little clearer?
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I'm writing an android application that has a search feature that needs to autocomplete from a list of stores. This list will only have up to a few thousand stores in it.
My current methodology is to send a LIKE query to the database every few hundred ms after the user has stopped typing and to populate the autocomplete list with these results.
Would using this method be stressful to the database?
It has been suggested to me that this wouldn't work because making continuous calls would be poor for users with a slow connection and that I should load all the stores into memory and filter from there.
At my work I ran into a similar problem a few months back. The contents of a text box filled by the user were supposed to filter their available options to choose from in a list of strings. The list needed to be updated every time the user typed a key so database calls to fetch records that matched their text were being made several times a second.
This ended up being wayy to slow to update as someone was typing, and this was only with several thousand records and with a server that was being accessed on site.
If you want to update as quickly as someone can type, making that many database calls simply won't do. Users will get pretty antsy having to let their phone buffer to type in some text.
In Short: Make one databse call and load it up onto the phone, and run your filter algorithm from there.
Regularly syncing the list of stores from your back end to the user's device and implementing autocomplete locally is the best way to go.
The JobScheduler API provides a flexible way to set constraints on your background syncing processes.
I have a SearchView in ActionBar and I'm using onQueryTextListener with it. I have a Listview in activity's layout to which the ActionBar belongs. There are two Textviews in ListView. So, as user enter text into searchview, a web query(api) is performed on the text and the results(array) received are used to populate the listview. Just like AutoCompleteTextView but instead displaying results in listview.
I am using a HandlerThread to perform this query and populating the listview and I have implemented it in onQueryTextChange which is working.
But, the problem is that it takes long time to display results. The results are displayed after user is done entering input. However, I want results to be displayed as user enter text(Like Google suggest). How can I do this?
I imagine Google uses cached results on their servers to speed up the response to queries. You could use something like MemCache or Varnish to provide results faster. If the results require searches you could also improve the speed by using a search engine like Apache Solr or Lucene.
Google will also have very good server infrastructure with cached results being located all over the world so always near the user. The results will probably vary from server to server so that they give what local users want. I remember calculating a few years back based on trying to improve response times for online gaming that Europe is something like a tenth of a second from North America.
You can also fake this information. You can download results that you anticipate a user would want on to their device and fill the autocomplete from a database on the device. A request can also be sent to the server at the same time and the autocomplete results updated once the response is received from the server. This to some extent depends on the complexity of what you are searching. If there are only a limited number of results you could easily store them all on the device.
I currently have several fragment tabs , each with a feed of user statuses, being I have about a 100 other users posting from their accounts there is constantly new data every few minutes. currently the users only choice is to switch fragments back and fourth to get the entire fragment to reload which sends another http request and returns the new data as well as all the old data the user already had. it just doesnt seem efficient, know there has to be a better way. Can someone give me a overview of the most efficient way to keep this data fresh without having the user switch tabs back and fourth?
Is this where using sqlite and/or services comes into play?
Though some developers and designers argue between if content should be refreshed automatically of not, I argue content like streams shouldn't be refreshed automatically unless you are expecting very less incoming data.
I have used twitter4j to stream tweets and refresh automatically in one of my test app, twitter4j has a listener that lets you know when new tweets are received. First I pushed data into ListView as soon as new feeds were received and it was kind of flashy but, efficient. Then I queued up data until it reached certain threshold and pushed data into ListView, it was bit better. I thought it was good enough but, when I monitored my "Data Usage", i quite realized why I shouldn't refresh automatically.
Now here are some example implementation:
(Suggest) Do some type of polling or I recommend you to implement
push(like GCM) to let your client-side know that there's new content
in the server.
(Option) Use SyncAdapter with server triggered sync
(Recommend) Let user be in control, it's more than okay to use
Pull-to-Refresh pattern like Facebook or ActionBar sync button like
Google+. It will not make UserExperience any bad.
Now here's how your sample request API should be like or you can match your own config:
{
"fromIndex": 0,
"toIndex": 10
...
}
well, i'll try to give you a general overview to see if you can get it without the need of getting into deepest details, an idea it just came to my mind:
1- you need to configure your server to retrieve from an "specific" point of the content or retrieve a token that you will pass to the server (on next HttpRequest) to know from where part of the content or from where "index" start to send the content again.
2- you need to have a Listener (i dont know how you are showing your data but this is the case of a ListView) that tells you when the user is closely to get to the end of the ListView and let't say if there are already 10 elements, in element 7 the Listener should call the method to get more content from the server.
3- Yes, you need to keep the data already retrieve in SQLite temporarily, you can't use SharedPreference to keep it because it probably would be a lot of data and maintain it in memory could be a bad idea, writing a file is not an option here neither, so SQLite is your best friend in this case.
Maybe there would be more problems specifics about what you are trying to achieve but to me in a general perspective, those 3 points should at least help you in the direction to go.
I need to implement an Android application which allows users to browse a large number of images (10000) stored on a server.
I can use REST style HTTP calls to get the information about images e.g. GET http://uri...?itemsstart=n&itemscount=m which returns me the names and locations of images.
I have a content provider with a cursor adapter which I can use to get this information. I’d like to hook this up to a GridView to allow for scrolling of images.
There are several examples here and elsewhere on the web about using similar scenario for a small fixed number of images : you just use setAdapter on the GridView or ListView and it will do its magic when user initiates a database query via menu etc.
In my case, user should be able to scroll through images continuously while the app is loading them in “chunks” in the background.
My question is how and when to initiate a new query to get a new “chunk” of images in such a way that my CursorAdapter/GridView combination will be updated for continuous scrolling?
I would appreciate some advice about this scenario.
I'm pretty sure it's not viable to do what I'd like to based on some initial research, but I figured it couldn't hurt to ask the community of experts here in case someone knows a way.
I'd like to create a custom field for contacts that the user is able to edit from the main Contacts app; however, the user should only be allowed to select from a list of four specific values. A short list of string values would be ideal, but an int with a min/max range would suffice.
I'm interested in knowing if it's possible either way, but also wondering if it make sense to go this route performance wise. More specifically, would it be better to look up a contact (based on a phone number) each time a call or SMS message is received or better to store my own set of data (consisting of name, numbers, and the custom field) and just syncing contact info in a thread every so often? Or syncing contacts the first time the app is run and then registering for changes using ContentObserver?
Here is a similar question with an answer that explains how to add a custom field to a contact.
Thanks in advance.
I don't see the purpose to have your own set of data against contacts stored in your separate database, as you obviously will run into sync issues. You can use the mimetype and store whatever you want against the contact, in the manner you linked.
Whenever you want to looup contacts you can do that by using your custom mimetype. You get the contact id (from ContactsContract.Data.CONTENT_URI), and then you run another query to get the contact details (from ContactsContract.Contacts.CONTENT_URI). Please note these are different tables.
I'd like to create a custom field for contacts that the user is able to edit from the main Contacts app
I don't see that possible, editable from the main app, when you use your custom mimetypes, and you don't have much options here. The main contact app will display only the fields that are in SDK. You can store details against contacts but they won't show up in the inbuilt edit contact screen.