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Contract class for a weather application called Sunshine
/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.android.sunshine.app.data;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.net.Uri;
import android.provider.BaseColumns;
import android.text.format.Time;
/**
* Defines table and column names for the weather database.
*/
public class WeatherContract {
// The "Content authority" is a name for the entire content provider, similar to the
// relationship between a domain name and its website. A convenient string to use for the
// content authority is the package name for the app, which is guaranteed to be unique on the
// device.
public static final String CONTENT_AUTHORITY = "com.example.android.sunshine.app";
// Use CONTENT_AUTHORITY to create the base of all URI's which apps will use to contact
// the content provider.
public static final Uri BASE_CONTENT_URI = Uri.parse("content://" + CONTENT_AUTHORITY);
// Possible paths (appended to base content URI for possible URI's)
// For instance, content://com.example.android.sunshine.app/weather/ is a valid path for
// looking at weather data. content://com.example.android.sunshine.app/givemeroot/ will fail,
// as the ContentProvider hasn't been given any information on what to do with "givemeroot".
// At least, let's hope not. Don't be that dev, reader. Don't be that dev.
public static final String PATH_WEATHER = "weather";
public static final String PATH_LOCATION = "location";
// To make it easy to query for the exact date, we normalize all dates that go into
// the database to the start of the the Julian day at UTC.
public static long normalizeDate(long startDate) {
// normalize the start date to the beginning of the (UTC) day
Time time = new Time();
time.set(startDate);
int julianDay = Time.getJulianDay(startDate, time.gmtoff);
return time.setJulianDay(julianDay);
}
/* Inner class that defines the table contents of the location table */
public static final class LocationEntry implements BaseColumns {
public static final Uri CONTENT_URI =
BASE_CONTENT_URI.buildUpon().appendPath(PATH_LOCATION).build();
public static final String CONTENT_TYPE =
ContentResolver.CURSOR_DIR_BASE_TYPE + "/" + CONTENT_AUTHORITY + "/" + PATH_LOCATION;
public static final String CONTENT_ITEM_TYPE =
ContentResolver.CURSOR_ITEM_BASE_TYPE + "/" + CONTENT_AUTHORITY + "/" + PATH_LOCATION;
// Table name
public static final String TABLE_NAME = "location";
// The location setting string is what will be sent to openweathermap
// as the location query.
public static final String COLUMN_LOCATION_SETTING = "location_setting";
// Human readable location string, provided by the API. Because for styling,
// "Mountain View" is more recognizable than 94043.
public static final String COLUMN_CITY_NAME = "city_name";
// In order to uniquely pinpoint the location on the map when we launch the
// map intent, we store the latitude and longitude as returned by openweathermap.
public static final String COLUMN_COORD_LAT = "coord_lat";
public static final String COLUMN_COORD_LONG = "coord_long";
public static Uri buildLocationUri(long id) {
return ContentUris.withAppendedId(CONTENT_URI, id);
}
}
/* Inner class that defines the table contents of the weather table */
public static final class WeatherEntry implements BaseColumns {
public static final Uri CONTENT_URI =
BASE_CONTENT_URI.buildUpon().appendPath(PATH_WEATHER).build();
public static final String CONTENT_TYPE =
ContentResolver.CURSOR_DIR_BASE_TYPE + "/" + CONTENT_AUTHORITY + "/" + PATH_WEATHER;
public static final String CONTENT_ITEM_TYPE =
ContentResolver.CURSOR_ITEM_BASE_TYPE + "/" + CONTENT_AUTHORITY + "/" + PATH_WEATHER;
public static final String TABLE_NAME = "weather";
// Column with the foreign key into the location table.
public static final String COLUMN_LOC_KEY = "location_id";
// Date, stored as long in milliseconds since the epoch
public static final String COLUMN_DATE = "date";
// Weather id as returned by API, to identify the icon to be used
public static final String COLUMN_WEATHER_ID = "weather_id";
// Short description and long description of the weather, as provided by API.
// e.g "clear" vs "sky is clear".
public static final String COLUMN_SHORT_DESC = "short_desc";
// Min and max temperatures for the day (stored as floats)
public static final String COLUMN_MIN_TEMP = "min";
public static final String COLUMN_MAX_TEMP = "max";
// Humidity is stored as a float representing percentage
public static final String COLUMN_HUMIDITY = "humidity";
// Humidity is stored as a float representing percentage
public static final String COLUMN_PRESSURE = "pressure";
// Windspeed is stored as a float representing windspeed mph
public static final String COLUMN_WIND_SPEED = "wind";
// Degrees are meteorological degrees (e.g, 0 is north, 180 is south). Stored as floats.
public static final String COLUMN_DEGREES = "degrees";
public static Uri buildWeatherUri(long id) {
return ContentUris.withAppendedId(CONTENT_URI, id);
}
/*
Student: This is the buildWeatherLocation function you filled in.
*/
public static Uri buildWeatherLocation(String locationSetting) {
return CONTENT_URI.buildUpon().appendPath(locationSetting).build();
}
public static Uri buildWeatherLocationWithStartDate(
String locationSetting, long startDate) {
long normalizedDate = normalizeDate(startDate);
return CONTENT_URI.buildUpon().appendPath(locationSetting)
.appendQueryParameter(COLUMN_DATE, Long.toString(normalizedDate)).build();
}
public static Uri buildWeatherLocationWithDate(String locationSetting, long date) {
return CONTENT_URI.buildUpon().appendPath(locationSetting)
.appendPath(Long.toString(normalizeDate(date))).build();
}
public static String getLocationSettingFromUri(Uri uri) {
return uri.getPathSegments().get(1);
}
public static long getDateFromUri(Uri uri) {
return Long.parseLong(uri.getPathSegments().get(2));
}
public static long getStartDateFromUri(Uri uri) {
String dateString = uri.getQueryParameter(COLUMN_DATE);
if (null != dateString && dateString.length() > 0)
return Long.parseLong(dateString);
else
return 0;
}
}
}
@mkVictimized

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@mkVictimized mkVictimized commented Dec 10, 2016

it's helpful.

@wushbin

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@wushbin wushbin commented Mar 8, 2017

thanks

@TusharSharma23

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@TusharSharma23 TusharSharma23 commented Jun 23, 2018

why enums are not used for constants?

@doct0rX

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@doct0rX doct0rX commented Jul 13, 2018

@TusharSharma23 they doing that for Android performance pattern;
https://www.youtube.com/watch?v=Hzs6OBcvNQE
and I certainly think that they are dump to trade some memory for significant code quality!

@chethankumartk

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@chethankumartk chethankumartk commented Oct 12, 2018

Thanks a lot :)

@ososstar

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@ososstar ososstar commented Jan 31, 2019

well into weather table i see 10 columns but they're 9 without COLUMN_WEATHER_ID

@getsadzeg

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@getsadzeg getsadzeg commented Apr 22, 2019

@ososstar I think it's different id. _id(which is primary key + autoincrement) and _count are provided by BaseColumns interface it seems.

@imhnna

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@imhnna imhnna commented May 15, 2019

nice

@ashwanisng

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@ashwanisng ashwanisng commented Mar 30, 2020

very helpful..!!

@FTW-Khushal

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@FTW-Khushal FTW-Khushal commented Jul 7, 2020

i was here (with 2020 corona pandemic)

@shivanshuraj

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@shivanshuraj shivanshuraj commented Dec 5, 2020

Thanks :)

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