Description
Mobile Applications Development
Uses: Internet, RecyclerView, Option-Menus, Multiple AsyncTasks,
JSON Data, Swipe-Refresh, Dialogs, SQLite Database
App Highlights:
x This app allows the user to display a sorted list of selected stocks. List entries include the stock symbol (and
company name), the current price, the daily price change amount and price percent change.
x There is no need to use a different layout for landscape orientation in this application.
x Selected stock symbols and the related names should be stored in the device’s SQLite Database.
x A Stock class should be created to represent each individual stock in the application. Required data includes:
Stock Symbol (String), Company Name (String), Price (double), Price Change (double), and Change
Percentage (double).
x Clicking on a stock opens a browser displaying the Market Watch web page for that stock
x Swipe-Refresh (pull-down) refreshes stock data
x The application is made up of 1 activity, shown below:
Add Stock Options-Menu
Item (shown as Icon)
RecyclerView list of Stocks (list
entries have their own layout)
List scrolls up & down
Long-Click on a Stock entry to
delete (with delete confirmation)
Click on a Stock entry opens a
web browser to the Market
Watch site for the selected stock
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 2 of 18
Document Contents: Application Behaviors:
A) Internet Data A) Add Stocks
B) Application Behavior Diagrams: B) Delete Stocks
C) Application Behavior Flowcharts C) Refresh Stock Data
D) Database D) Open Browser with Stock Data
E) Development Plan
A) Internet Data:
Downloading data for a stock symbol requires 2 downloads – one download to acquire the full stock symbol and
company name, and a second download to acquire the financial data for the stock. See the “Adding a Stock”
flowchart later in this document for development details.
Download 1: Stock Symbol & Company Data
When selecting a stock, a user can enter a partial or complete stock symbol or company name. This information is
used to download a list of stocks matching the provided name data. This downloaded list is presented to the user
as a selectable list of stocks that match their criteria.
Download Source: http://stocksearchapi.com
NOTE: You MUST sign up with the http://stocksearchapi.com website to get an API KEY. Your API KEY must be
supplied with all stock queries. Once you sign up (the only data they need is an email address) – log in to access
your API Key (shown with Your Account).
Query Format: http://stocksearchapi.com/api/?api_key=your-api-key-here&search_text=user-entered-string
For example, if your API Key was “ABC123xyz” and the user-entered text was “CSO”, your full URL would be:
http://stocksearchapi.com/api/?api_key= ABC123xyz&search_text=CSO
Download Results Example:
Results are returned in JSON format, as a JSONArray containing the results data from the query. The data we are
interested in is the “company_name” and “company_symbol”.
Your results will include either ONE stock (Example using search text “TSLA”):
(When only one stock matches the user’s criteria, no list-selection-dialog is needed)
[
{
“company_name”:”Tesla Motors, Inc.”,
“company_symbol”:”TSLA”,
“listing_exchange”:”NASDAQ”
}
]
Or two or more Stocks (Example using search text “CSO”)
(When multiple stocks matches the user’s criteria, a list-selection-dialog is needed)
[
{
“company_name”:”Cornerstone OnDemand, Inc.”,
“company_symbol”:”CSOD”,
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 3 of 18
“listing_exchange”:”NASDAQ”
},
{
“company_name”:”CSOP FTSE China A50 ETF”,
“company_symbol”:”AFTY”,
“listing_exchange”:”NYSE ARCA”
},
{
“company_name”:”CSOP MSCI China A International Hedged ETF”,
“company_symbol”:”CNHX”,
“listing_exchange”:”NYSE ARCA”
},
{
“company_name”:”CSOP China CSI 300 A-H Dynamic ETF”,
“company_symbol”:”HAHA”,
“listing_exchange”:”NYSE ARCA”
}
]
Or NO stock (no match found)
Response Code: 404 Not Found
Download 2: Stock Financial Data
When you have the desired stock symbol (and company name), you use the stock symbol to download financial
data for that stock.
Download Source: http://finance.google.com (No sign up or API Key is necessary)
Query Format: http://finance.google.com/finance/info?client=ig&q=user-selected-stock-symbol
For example, if the selected stock symbol was TSLA, your full URL would be:
http://finance.google.com/finance/info?client=ig&q=TSLA
Download Results:
Results are returned in JSON format, as a JSONArray containing the results data from the query. The data we
are interested in is highlighted below.
Your results will include either ONE stock (Example using search text “TSLA”):
Note, the first 2 characters in the JSON results are “//”. These must be removed before parsing as JSON data.
//[
{
“id”:”12607212″,
“t”:”TSLA”,
“e”:”NASDAQ”,
“l”:”277.99″,
“l_fix”:”277.99″,
“l_cur”:”277.99″,
“s”:”0″,
“ltt”:”3:50PM EST”,
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 4 of 18
“lt”:”Feb 21, 3:50PM EST”,
“lt_dts”:”2017-02-21T15:50:19Z”,
“c”:”+5.76″,
“c_fix”:”5.76″,
“cp”:”2.12″,
“cp_fix”:”2.12″,
“ccol”:”chg”,
“pcls_fix”:”272.23″
}
]
Note, the first 2 characters in the JSON results are “//”. These must be removed before parsing as JSON data.
Or NO stock (no match found)
Response Code: 400 Bad Request
The data contained in the JSON financial data is as follows (those we need are highlighted):
x id Internal Stock Identifier
x t Ticker
x e Exchange
x l Last Trade Price (lowercase “L”)
x l_fix (Same as last trade price)
x l_cur Last Trade Price With Currency (Same as Last Trade Price if stock trades in Dollars,
otherwise alternate currency is shown.)
x s LastTradeSize (always seems to be zero)
x ltt Last Trade TimeStamp
x lt Last Trade Time & Date Formatted
x lt_dts Last Trade Time & Date Formatted – Z time
x c Price Change Amount (always with +/-)
x c_fix Price Change Amount (No “+” when positive, “-“ if negative)
x cp Price Change Percentage
x cp_fix (Always the same as Price Change Percentage)
x ccol “chr” or “chg”
x pcls_fix Previous Close Price
Always check to be sure the “Ticker” value (the stock symbol) matches the symbol you were trying to download.
The Stock Symbol and Company Name, and the Last Trade Price, Price Change Amount & Price Change
Percentage make up the data for one stock. Your Stock class should contain these 5 data elements.
Using these 5 data elements, you can create a Stock object with all data reflecting the user’s choice.
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 5 of 18
B) Application Behavior Diagrams:
1) App MainActivity
“Add Stock” action is
an Options-Menu
with a single item
(shown as Icon)
Each stock entry contains the
Stock Symbol (AAPL), the
company name (Apple Inc.),
the Last Trade Price (135.72),
the price change direction
(▲ for positive Price Change
Amount, ▼ for negative
Price Change Amount), the
Price Change Amount (0.38),
and the Price Change
Percentage (0.28%) in
parentheses.
If the stock’s Price Change
Amount is a positive value,
then entire entry should use
a green font. If the Price
Change Amount is a negative
value, then entire entry
should use a red font.
A scrollbar should be
present along the
right-hand side
Long-Click on a Stock
entry to delete (with
delete confirmation)
Clicking on a Stock entry opens a
web browser to the Market
Watch site for the selected stock
RecyclerView list
entries have their
own layout
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 6 of 18
1) Adding a stock – only one stock matched the search string (Stock Selection dialog should only allow capital
letters):
2) Adding a stock – multiple stocks matched the search string (Stock Selection dialog should only allow capital
letters, stock selection dialog should display the stock symbol and company name):
AMZN
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 7 of 18
3) Adding a stock with no Network Connection (No buttons on the error dialog):
4) Adding a stock – specified stock is a duplicate (Stock Selection dialog should only allow capital letters, No
buttons on the dialog):
AMZN
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 8 of 18
1) Adding a stock – specified stock is not found (Stock Selection dialog should only allow capital letters, No buttons
on the dialog):
6) Swipe-Refresh (pull-down) reloads (re-downloads) current stock data:
WXYZ
Pull
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 9 of 18
7) Swipe-Refresh attempt with no network connection (No buttons on the error dialog):
8) Long-Press on a stock to delete it:
Pull
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 10 of 18
9) Click on a stock to open the MarketWatch.com website entry for the selected stock:
MarketWatch URL’s are in the form: http://www.marketwatch.com/investing/stock/some_stock
For example: http://www.marketwatch.com/investing/stock/TSLA
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 11 of 18
C) Application Behavior Flowcharts:
a) Adding a Stock
Display Add Stock
Symbol Entry
Dialog
Download
Stock Name
Details
(Async)
Execute an Async Task (using entered symbol)
http://stocksearchapi.com/api/
?api_key=Your_API_Key+Goes_Here
&search_text=User_Entry
(This gets you stock symbols and
company names)
Did you
Get a Stock
result?
Display a list of the
resulting Stock Symbols
& Company Names in a
Dialog
No Stock Found Multiple Stocks
Send Selected Symbol &
Company Name to
MainActivity
(i.e., make a
“processNewStock”
method in MainActivity)
ONE Stock
Show Error Dialog
Done
Selection Made Done
Dialog Cancelled
Download
Stock Data (Async)
Execute an Async Task
http://finance.google.com/finance/info/
?client=ig
&q=TSLA
(This gets you stock financial data)
Parse JSON Results
in Async’s
onPostExecute
Parse JSON Results
in onPostExecute
Did you get
a response?
No Stock Found
Build Stock object and
send to MainActivity
(i.e., make an
“addNewStock” method
in MainActivity)
Yes
Show Error Dialog
No Stock?
Duplicate
Stock?
Yes
Add Stock to
Stock List
No
Select
“Add Stock”
Menu option
from Main
Activity
Select
“Add Stock”
Menu option
from Main
Activity
Add Stock Process Flow
Sort Stock List
Add Stock to DB
Notify Adapter
of Changed
Dataset
Yes Connected to
Network?
Show Error Dialog
No
Done
MainActivity
AsyncTask1
doInBackground
AsyncTask1
onPostExecute
AsyncTask2
doInBackground
AsyncTask2
onPostExecute
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 12 of 18
b) Swipe-Refresh (pull-down) List:
Pull-Down
(Swipe) to
Refresh Data
Pull-Down
(Swipe) to
Refresh Data
Connected to
Network?
Show Error Dialog
No
Create a temporary
copy of the Stock
List
Yes
Clear the Stock List
(Do not clear the
temporary copy!)
For Each Stock in
the Temporary
Stock List:
Done
Download
Stock Data (Async)
Parse JSON Results
in onPostExecute
Did you get
a response?
Build Stock object and
send to MainActivity
(i.e., make an
“addNewStock” method
in MainActivity)
Show Error Dialog
No Stock?
Duplicate
Stock?
Add Stock to
Stock List
Sort Stock List Add Stock to DB
Notify Adapter
of Changed
Dataset
More Stocks To Process
No Stock
Found
Yes
Yes
No No More Stocks
Swipe-Refresh Process Flow
More Stocks
To Process
Done
Stop the Swipe
Refreshing
No
More
Stocks
MainActivity
AsyncTask2
doInBackground
AsyncTask2
onPostExecute
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 13 of 18
c) Sartup Process:
On Appliction
Startup
On Appliction
Startup
Connected to
Network?
Show Error Dialog
No
Get all Stocks from
the DB, store in a
Temporary List
Yes
For Each Stock in
the Temporary
Stock List:
Done
Download
Stock Data (Async)
Parse JSON Results
in onPostExecute
Did you get
a response?
Build Stock object and
send to MainActivity
(i.e., make an
“addNewStock” method
in MainActivity)
Show Error Dialog
No Stock?
Duplicate
Stock?
Add Stock to
Stock List
Sort Stock List Add Stock to DB
Notify Adapter
of Changed
Dataset
More Stocks To Process
No Stock
Found
Yes
Yes
No No More Stocks
Startup Process Flow
More Stocks
To Process
Done
No
More
Stocks
MainActivity
AsyncTask2
doInBackground
AsyncTask2
onPostExecute
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 14 of 18
d) Long-Press Delete Stock:
Delete Stock Process Flow
Display Delete Stock
Confirmation
Dialog
Long-Click on a
Stock from the
List in Main
Activity
Long-Click on a
Stock from the
List in Main
Activity
Confirmed
Done
Cancelled
Remove Stock
from Stock List
Delete Stock
from DB
Notify Adapter
of Changed
Dataset
MainActivity
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 15 of 18
D) Database
Your application must store the Stock Symbol and Company Name in the android device’s SQLite
database. You will need a Database handler class as we have done in class (you have a posted example
of a Database handler that you can use as a model).
StockWatchTable
StockSymbol CompanyName
AAPL Apple, Inc
AMZN Amazon.com, Inc.
… …
private static final String DATABASE_NAME = “StockAppDB”;
private static final String TABLE_NAME = “StockWatchTable”;
private static final String SYMBOL = “StockSymbol”;
private static final String COMPANY = “CompanyName”;
x DB creation (done in onCreate):
CREATE TABLE TABLE_NAME (
SYMBOL TEXT not null unique,
COMPANY TEXT not null)
x DB Add (Sample method to add a stock to the DB):
public void addStock(Stock stock) {
Log.d(TAG, “addStock: Adding ” + stock.getSymbol());
ContentValues values = new ContentValues();
values.put(SYMBOL, stock.getSymbol());
values.put(COMPANY, stock.getCompany());
database.insert(TABLE_NAME, null, values);
Log.d(TAG, “addStock: Add Complete”);
}
x DB Delete (Sample method to delete a stock from the DB):
public void deleteStock(String symbol) {
Log.d(TAG, “deleteStock: Deleting Stock ” + symbol);
int cnt = database.delete(
TABLE_NAME, “SYMBOL = ?”, new String[] { symbol });
Log.d(TAG, “deleteStock: ” + cnt);
}
CS 442 Mobile Applications
Development (Android Section)
© Christopher Hield 16 of 18
x DB Load All (Sample method to get all stock-company entries from the DB):
public ArrayList<String[]> loadStocks() {
Log.d(TAG, ” loadStocks: Load all symbol-company entries from DB”);
ArrayList<String[]> stocks = new ArrayList<>();
Cursor cursor = database.query(
TABLE_NAME, // The table to query
new String[]{ SYMBOL, COMPANY }, // The columns to return
null, // The columns for the WHERE clause, null means “*”
null, // The values for the WHERE clause, null means “*”
null, // don’t group the rows
null, // don’t filter by row groups
null); // The sort order
if (cursor != null) { // Only proceed if cursor is not null
cursor.moveToFirst();
for (int i = 0; i < cursor.getCount(); i++) { String symbol = cursor.getString(0); // 1st returned column String company = cursor.getString(1); // 2nd returned column stocks.add(new String[] {symbol, company}); cursor.moveToNext(); } cursor.close(); } return stocks; } CS 442 Mobile Applications Development (Android Section) © Christopher Hield 17 of 18 E) Development Plan 1) Create the base app: a. MainActivity with RecyclerView & SwipeRefreshLayout b. Stock Class c. RecyclerView Adapter d. RecyclerView ViewHolder e. Create fake “dummy” stocks to populate the list in the MainActivity onCreate. f. Add the onClick and onLongClick methods. The onLongClick should delete an entry. The onClick can open a Toast message for now. g. Add Stock options-menu opens dialog, on confirmation you can open a Toast message for now. h. SwipeRefresh callback method can open a Toast message for now. 2) Add the database elements: a. Create the database handler. b. Add database handler calls to MainActivity (load, add, delete) c. Code the onClick method to open the browser to the stock’s Market Watch site. 3) Add the internet elements and final integration: a. Create the Stock Symbol – Company Name downloader/parser AsyncTask (stocksearchapi.com) b. Create the Stock Financial Data downloader/parser AsyncTask (finance.google.com) c. Add a method to MainActivity that allows the Stock Symbol – Company Name downloader/parser AsyncTask to send the newly downloaded Stock Symbol & Company Name data back to MainActivity. This method should create and execute the Stock Financial Data downloader/parser AsyncTask. d. Add a method to MainActivity that allows the Stock Financial Data downloader/parser AsyncTask to send the newly created Stock back to MainActivity. e. Implement the Add Stock feature (this uses the results of the above tasks) f. Implement the SwipeRefresh callback to re-download the Stock Financial Data for the loaded stocks g. Add alerts when startup, add, & refresh are attempted when no internet connection is available. CS 442 Mobile Applications Development (Android Section) © Christopher Hield 18 of 18 Assignment Assistance The TAs for our course is available to assist you with your assignment if needed. Questions on assignment requirements and course concepts can be sent to the instructor. Submissions & Grading 1) Submissions must consist of your zipped project folder (please execute Build =>Clean Project before
generating the zip file).
2) Submissions should reflect the concepts and practices we cover in class, and the requirements
specified in this document.
3) Late submissions will be penalized by 10% per week late. (i.e., from one second late to 1 week late:
10% penalty, from one week plus one second late to 2 weeks late: 20% penalty, etc.).
4) Grading will be based upon the presence and proper functionality of all features and behaviors
described in this document.
NOTE
This assignment is worth 300 points. This means (for example) that if you get 89% on this
assignment, your recorded score will be:
(89% * 300 points = 267 points)
Note that this also means that the 10% late submission penalty will be 10% * 300 points = 30 points.
If you do not understand anything in this handout, please ask.
Otherwise the assumption is that you understand the content.
Unsure? Ask!
