Develop Reference

Save a List of custom object in savedInstanceState

I am currently building an app to retrieve information for a remote server. the data received are JSON and I am build a list of Data using the class below :
public class RedditData {
private RedditTopic data;
public RedditTopic getData() {
return data;
}
}
and RedditTopic class is defined as below:
public final class RedditTopic {
private static final String TAG = RedditTopic.class.getSimpleName();
private String author;
private String thumbnail;
private String title;
private String num_comments;
private long created_utc;
private String data;
private String name;
public RedditTopic(){};
public String getData() {
return data;
}
public String getAuthor() {
return author;
}
public String getThumbnail(){
return thumbnail;
}
public String getTitle(){
return title;
}
public String getComments(){
return num_comments + " comments";
}
public long getCreated_utc(){
return created_utc;
}
public String getRedditName(){
return name;
}
}
both of these classes are used to translate a JSON into an Object formatted data.
I do not want to really change them to make them Parceable to avoid impacting the extraction of JSON.
I have added :
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
Log.d(TAG, ">>>>>>>>>>>>>>>>>>>>>>>> SAVE");
savedInstanceState.putParcelableArrayList("RedditList", myListOfData );
super.onSaveInstanceState(savedInstanceState);
}
#Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
Log.d(TAG, ">>>>>>>>>>>>>>>>>>>>>>>> RESTORE");
List<RedditData> myListOfData = savedInstanceState.getParcelableArrayList("RedditList");
}
Android complain because I need to implement Parceable in my class RedditData and I assume probably in the RedditTopic Class as well because RedditData returned a List of RedditTopic.
Is there a better way to do it? keep the List as I have it without requiring the Parceable option.
I do not have a List of String, it's a list of object.
Any idea?
Regards

Make your model objects parcleable.
There is a great extension, https://plugins.jetbrains.com/plugin/7332-android-parcelable-code-generator that will generate the neccesary parcelable methods for your class.
I highly recommend it.

How to autocomplete text in a textview with firebase database in an android app

I want something like below image. Image is of autocomplete search from firebase website itself.
I've seen many post about this, but those posts does not seem to work with firebase above 3.0.
I want to search in an autcomplete textview either with entering name or number. Here's an entry from my database
In short, it should suggest entries from my firebase database as I start typing.

One solution for achieving this would be loading your data from the realtime database into an ArrayList before you start searching.
So to do this first you'll need to check when the Firebase Listener
is done retrieving your data from the database. Firebase Listeners are not executed in sequence and the ValueListener is always executed last. So you can do something like retrieve your data through a ChildListener and then execute to ValueListener to make sure the data is completely retrieved rootRef.addListenerForSingleValueEvent()
Later when your data is retrieved and stored in a arraylist you can follow this to add the search functionality
Hope it helps!

First of all add the required dependencies of firebase and glide or other dependency for image view in build.gradle .
Create a reference for the tree as follows
mUserDatabase = FirebaseDatabase.getInstance().getReference("YourTreeRootNameHere");
Pass the string in the text field with a onTextChanged method to the following function firebaseUserSearch. Make necessary changes in the following function according to your code.
private void firebaseUserSearch(String searchText) {
Query firebaseSearchQuery = mUserDatabase.orderByChild("sName").startAt(searchText).endAt(searchText + "\uf8ff");
FirebaseRecyclerAdapter<Users, SearchActivity.UsersViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Users, SearchActivity.UsersViewHolder>(
Users.class,
R.layout.list_layout,
SearchActivity.UsersViewHolder.class,
firebaseSearchQuery
) {
#Override
protected void populateViewHolder(SearchActivity.UsersViewHolder viewHolder, final Users model, final int position) {
viewHolder.setDetails(getApplicationContext(), model.getName(), model.getPlace(), model.getImage());
}
};
mResultList.setAdapter(firebaseRecyclerAdapter);
}
// View Holder Class
public static class UsersViewHolder extends RecyclerView.ViewHolder {
View mView;
public UsersViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
public void setDetails(Context ctx, String userName, String userStatus, String userImage){
TextView user_name = (TextView) mView.findViewById(R.id.name_text);
TextView user_status = (TextView) mView.findViewById(R.id.status_text);
ImageView user_image = (ImageView) mView.findViewById(R.id.profile_image);
user_name.setText(userName);
user_status.setText(userStatus);
Glide.with(ctx).load(userImage).into(user_image);
}
}
Create your layout for recyclerView and define the data model class. For example this function uses a Users.class that is shown below.
public class Users {
public String name, image, place;
public Users(){
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getImage() {
return image;
}
public void setImage(String image) {
this.image = image;
}
public String getPlace() {
return place;
}
public void setPlace(String status) {
this.place = status;
}
public Users(String name, String image, String place) {
this.name = name;
this.image = image;
this.place = place;
}
}

sort List of Object by one of Object's field

I understand that Collections.sort(list) does the work for a list of strings, but what about list of Object? Say I have this object Contact:
public class Contact implements Serializable {
private SerializableBitmap picture;
private String name;
private String location;
public Contact() {
}
public void setPicture(SerializableBitmap picture) {
this.picture = picture;
}
public void setName(String name) {
this.name = name;
}
public void setLocation(String location) {
this.location = location;
}
public SerializableBitmap getPicture() {
return picture;
}
public String getName() {
return name;
}
public String getLocation() {
return location;
}
}
Then I have an ArrayList of this object. Is it possible to sort the list based on Contact name? I'm trying to populate it with ListView, but it should be in ascending order.

You need to implement a Custom Comparator like the following
public class ContactComparator implements Comparator<Contact> {
public int compare(Contact contact1, Contact contact2) {
//In the following line you set the criterion,
//which is the name of Contact in my example scenario
return contact1.getName().compareTo(contact2.getName());
}
}
Then all you need is to call it like this (anywhere in your code where you need to have your contacts sorted):
Collections.sort(myContacts, new ContactComparator());
myContacts is the list of Contact objects you need to sort (you name it list in your question).

If you are populating a List you should populate it with just a string[] then find Contact by name to get the contact object back. Then you can sort the string[] for the listview.
As seen in the comment you need to create a new array of object string anyway. It's totally up to you which way you want to do it.

how to get object's attributes

How can I get an object's attributes?
I created an object that has two fields, first one called Title containing the string value "title1" and second one called Description containing the string value "description1". I would like to get the strings inside.
The method item.toString() gets me the two strings one after the other. Is there a way to get the strings separatively?

Just create accessor methods for each field.
Assuming you have declared your fields like this:
private String title;
private String desciption;
create the accessor methods in your class definition like this:
public String getTitle() {
return title;
}
public String getDescription() {
return description;
}
then you just call these methods to get the appropriate value.

Class Declaration
public class Class_Name {
private String Category;
private String Category_Type;
public Class_Name () {
super();
}
public Class_Name(String Category, String Category_Type) {
super();
this.Category = Category;
this.Category_Type = Category_Type;
}
/*public Class_Name (String Category_Type) {
this.Category_Type = Category_Type;
}*/
public String getCategory() {
return Category;
}
public void setCategory(String Category) {
this.Category = Category;
}
public String getCategory_Type() {
return Category_Type;
}
public void setCategory_Type(String Category_Type) {
this.Category_Type = Category_Type;
}
}
In the class where you should use this Object to store and retrieve values.
//Create an object for this class
private Class_Name data;
// To save values
data.setCategory(sCategory);
data.setCategory_Type(sType);
// To retrieve values
String sCategory = data.getCategory();
String sType = data.getCategory_Type();

How to create a model containing arrays

I'm making a model for daily Forecast but I'm having some trouble with creating this model.
It has regular information (date, description...) but I need it to have various Strings of information in it for every 3 hours...(temperatures, wind speed, wind direction etc)
And that's where I don't know how to do it..maybe with an Array of some sort but not sure.
So far, here is what I have:
public class DayForecast implements Serializable{
private String date;
private String description;
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
}
Thx!

Try using ArrayList<HashMap<String,String>>. With this you can implement the same with less hassle and in organized manner.
Example usage:
ArrayList<HashMap<String,String>> list = new ArrayList<HashMap<String,String>>();
HashMap<String,String> data = new HashMap<String,String>();
data.put("description", your_string_description);
data.put("date", your_string_date);
data.put("other", your_string_other_information);
list.add(data);
And to get your data:
list.get(0).get("description"); //will return the string description in position 0
list.get(0).get("date"); //will return the string description in position 0 you can convert it to date if needed
note that the get(0) is the position in your arraylist since with this you can add more items let's say description.

It doesn't sound like an array of Strings would do it, since you mentioned temperature, wind-speed, wind-direction etc. I would create another model for that and store instances of it within the current one.
e.g.
public class WeatherCondition {
private double mTemperature;
private double mWindSpeed;
private String mDirection;
public WeatherCondition(double temperature, double windSpeed, String direction) {
mTemperature = temperature;
mWindSpeed = windSpeed;
mDirection = direction;
}
// ... setter and getter methods ...
}
and
public class DayForecast {
private String mDate;
private String mDescription;
private SparseArray<WeatherCondition> mWeatherConditions = new SparseArray<WeatherCondition>();
public WeatherCondition getWeatherCondition(int timeInHours) {
// return null if no weather condition was set
WeatherCondition weatherCondition = mWeatherConditions.get(timeInHours);
// or you could add some other logic here, if you would want the next available weather condition,
// but make sure to reflect that in the method name
return weatherCondition;
}
public void setWeatherCondition(int timeInHours, WeatherCondition weatherCondition) {
mWeatherConditions.append(timeInHours, weatherCondition);
}
// ... other setter and getter methods
}