CHAPTER 3&4 ZHONGWEI LI TouchDevelop Book

What are we covering Review of Chapter 1-2 TouchDevelop as a scripting language: actions, events, table and record types, global status and library references The Wall: using screen Output & Input Tap events Popping, Pushing | Title & Subtitle | else The Web: handling web-based resources Working with URLs Download and Upload files Structured data REST and web request

Wall: Output Simple Types Demo-1  Simple types on Wall Wall is the screen and accessible to any datatype  → post to wall Directions of output: set reverse & textbox  wall → set reversed(true)  wall → create text box(…) Wall Script

Wall: Output Composite Value Demo-2  Formatted CV on Wall Display of composite value produces a formatted result  Collections → list of items  Each item formatted in appropriate manner Wall Display of Composite Value: (0,0,0) 2/6/ :00 AM [123,456,-789] …

Wall: Output Other Types Media values  Table 3-1: Picture, Board, Song, Sound, Picture Album, Song Album Social values  Table 3-2: Appointment, Contact, Link, Location, Message, Place Home network values  Table 3-3: Media Player, Media Server, Printer Web values  Table 3-4: Web Request, Json Object, Xml Object

Wall: Input of Values from Touchscreen Wall API provides methods that prompt user to enter/pick value  Table 3-5: ask boolean/number/string  Table 3-5(cont): pick date/string/time Example of “prompting for input”  Demo-3

Board Wall: Update Contents Board: Demo-4  Pictures, massages and shapes as sprites Alter the value of currently posted items on Wall  wall → clear Use text box to alter text.  wall → create text box(…)  tb → set text(…) Use board to update sophisticated display  board → update on wall Wall Sprites Scripts: … board := media → create board(200) …

Wall: Tap Events Tap Wall events  Nearly one tap event for every datatype (that’s displayed on screen)  The tapped item is passed as a parameter to the event  Demo-5 Tap board events  Control over the displayed values (to be tapped)  Define variable with Board: Sprite/Sprite Set type in data section causes new event types available(Demo-6)  For sprites, even names has tap/swipe/drag(Demo-6)  More events associated with board(e.g. tap anywhere else)

Wall: Something else Pushing and Popping pages  Stack of pages (each page as an instance of the wall) Titles and Subtitles  Display titles on top of screen (Demo-7) Wall buttons  Button icons may be displayed as page buttons(bottom)  Buttons can trigger events(Demo-8)  Methods of buttons in Table 3-8 On-demand creation of output  empty space event

Web: Working with URLs Encoding & Decoding  Convert: Opening web browser at a specific webpage  web → browse(“url”)  Demo-9 When parsing special characters in a URL  web → url encode()  web → url decode() …abc%25, #?......abc%252 5%2c%23 %3f... encod e decod e

Web: Create and Use Links Use wall with web links  Demo-10 Use of Link datatype  Save link to people  Save link to web resources Wall can be used to hold links to websites  Table 4-2  Post (link) to the wall Check internet connections  web → is connected  web → connection type  web → connection name Wall Web Rerouces.txt,.png… Links to URL

Web: Download and Upload TouchDevelop API provides methods for accessing different kinds of web resources  Table 4-3 Download files (Demo-11)  Text or HTML  Picture  Sounds and music

Web: Downloading Info in JSON format Downloading structured data  Information extracting  web → download()  Special characters  web → html decode/encode Download JSON  web → download json()  Flickr & Twitter Figure 4-6 { "weather": { "curren_weather": [ { "humidity": "87", "pressure": "1005", "temp": "6", "temp_unit": "c”, "weather_code": "1", "weather_text": "Partly cloudy", "wind": [ {"dir": "ENE", "speed": "4", "wind_unit": "kph" } ] } ], "forecast": [ … JSON format: Weather2Weather2  Demo-12

6 c 4 ENE kph … 6 c 4 ENE kph … Web: Downloading Info in XML format XML format: Weather2  Demo-13 Processes  1. Fetch data as String  web → download()  2. Parse the string as XML  web → xml( ) Not easy to figure out the XML data?  Go over DTD Figure 4-8

REST Guidelines and Web Requests HTTP GET and POST requests  Access of RESTful web services HTTP PUT and Delete requests  Not supported by WP platform, yet there’re alternative choices provided by many RESTful web services API method web → create to construct HTTP requests  The request is an instance of Web Request type  The result comes back as an instance of Web Response type  Table 4-4, 4-5

Summary Wall Output & Input  Post & ask different types Updating Wall Contents  Text box & board Wall Events and Others  Tap wall events & Tap board events  Pushing & Popping pages  Title & Subtitles  Wall buttons URLs and Webpages  Web-based links & wall  Check internet connection Down(up)loading Files  Download text, pics, media contents  Uploading strings & pics Structured Data  Download JSON format  Download XML format REST and Web Request

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