The Ring programming language version 1.5 book - Part 8 of 31

Ring Documentation, Release 1.5
rowend()
rowstart([])
cellstart([ :style = styleheight(30)])
text("Password")
cellend()
cellstart([])
textbox([:name = "password" , :type = "password"])
cellend()
rowend()
rowstart([])
cellstart([ :style = styleheight(30) ])
cellend()
cellstart([])
submit([:value = "Login" ])
cellend()
rowend()
tableend()
formend()
divend()
divend()
}
Screen Shot:
The response page
#!c:ringbinring.exe -cgi
Load "weblib.ring"
Load "datalib.ring"
Load "ex25_users.ring"
Import System.Web
48.22. Users registration and Login 388

oUser = new UsersModel
oUser.Connect()
lResult = oUser.FindWith("username",aPageVars["username"])
new page {
if lResult
if sha256(aPagevars["password"]+oUser.Salt) = oUser.pwhash
text ("Correct Password!")
aPageVars["sessionid"] = str2hex(randbytes(32))
oUser.UpdateColumn("sessionid",aPageVars["sessionid"])
cookie("sessionid",aPageVars["sessionid"])
else
text ("Bad password!")
ok
else
text("Bad User Name!")
ok
}
oUser.Disconnect()
The next code for checking if the user needs to login or not
#!c:ringbinring.exe -cgi
Load "weblib.ring"
Load "datalib.ring"
Load "ex25_users.ring"
Import System.Web
oUser = new UsersModel
oUser.Connect()
lResult = oUser.FindWith("sessionid",aPageVars["sessionid"])
new page {
if lResult
text("User Name : " + oUser.username )
else
text("Please Login First!")
ok
}
oUser.Disconnect()
48.23 Database, ModelBase & ControllerBase classes
In this section we will see some code from datalib.ring
The next code presents the Database, ModelBase & ControllerBase classes
Import System.Web
Class Database
cServer = "localhost"
cUserName = "root"
cPassword = "root"
cDatabase = "mahdb"
Func Connect
48.23. Database, ModelBase & ControllerBase classes 389

con = mysql_init()
mysql_connect(con, cServer, cUserName, cPassWord,cDatabase)
Func Disconnect
mysql_close(con)
Func Query cQuery
mysql_query(con,cQuery)
Func QueryResult
return mysql_result(con)
Func QueryResultWithColumns
# return columns names + query result
return mysql_result2(con)
Func QueryValue
aResult = mysql_result(con)
if islist(aResult) and len(aResult) >= 1
aResult = aResult[1]
if len(aResult) >= 1
return aResult[1]
ok
ok
return 0
Func EscapeString x
if isstring(x)
return MySQL_Escape_String(con,x)
else
return MySQL_Escape_String(con,string(x))
ok
Private
con = NULL
Class ModelBase from Database
cTableName = ""
cSearchColumn = "name"
aColumns = []
aQueryResult = []
ID = 0
# set table name from class name
classname = lower(classname(self))
if right(classname,5) = :model
cTablename = left(classname,len(classname)-5)
ok
Func Insert
cValues = ""
for x in aColumns
cValues += "'" + EscapeString(aPageVars[x]) + "',"

Next
cValues = left(cValues,len(cValues)-1) # remove last comma
cColumns = ""
for x in aColumns
cColumns += x + ","
next
cColumns = left(cColumns,len(cColumns)-1)
query("insert into " + cTableName + "("+cColumns+") values (" +
cValues + ")" )
Func Update nID
cStr = ""
for x in aColumns
cStr += x + " = '" + EscapeString(aPageVars[x]) + "' , "
# the space after comma is necessary
Next
cStr = left(cStr,len(cStr)-2)
query("update " + cTableName + " set " + cStr + " where id = " + nID )
Func UpdateColumn cColumn,cValue
query("update " + cTableName + " set " + cColumn + " = '" +
EscapeString(cValue) + "' where id = " + self.ID )
Func Count cValue
query("SELECT count(*) FROM " + cTableName +
" where "+cSearchColumn+" like '" + EscapeString(cValue) + "%'")
return queryValue()
Func Read nStart,nRecordsPerPage
query("SELECT * FROM "+ cTableName+" limit " + EscapeString(nStart) + "," +
EscapeString(nRecordsPerPage) )
aQueryResult = queryResult()
Func Search cValue,nStart,nRecordsPerPage
query("SELECT * FROM "+ cTableName+" where "+cSearchColumn+" like '" +
EscapeString(cValue) + "%'" +
" limit " + EscapeString(nStart) + "," + EscapeString(nRecordsPerPage) )
aQueryResult = queryResult()
Func Find nID
query("select * from " + cTableName + " where id = " + EscapeString(nID) )
aResult = queryResult()[1]
# move the result from the array to the object attributes
ID = nID
cCode = ""
for x = 2 to len(aResult)
cCode += aColumns[x-1] + " = hex2str('" + str2hex(aResult[x]) + "')" + nl
next
eval(cCode)
Func FindWith cColumn,cValue

query("select * from " + cTableName + " where "+cColumn+" = '" +
EscapeString(cValue) + "'" )
aResult = queryResult()
if len(aResult) > 0
aResult = aResult[1]
else
return 0
ok
# move the result from the array to the object attributes
ID = aResult[1]
cCode = ""
for x = 2 to len(aResult)
cCode += aColumns[x-1] + " = hex2str('" + str2hex(aResult[x]) + "')" + nl
next
eval(cCode)
return 1
Func Delete ID
query("delete from " + cTableName + " where id = " + EscapeString(ID) )
Func Clear
cCode = ""
for x in aColumns
cCode += x + ' = ""' + nl
next
eval(cCode)
Func LoadModel
# create the columns array
query("SELECT * FROM "+ cTableName + " limit 0,1")
aQueryResult = QueryResultWithColumns()[1]
for x = 2 to len(aQueryResult)
aColumns + lower(trim(aQueryResult[x]))
next
# create attribute for each column
for x in aColumns
addattribute(self,x)
next
Func Connect
Super.Connect()
if nLoadModel = 0
nLoadModel = 1
LoadModel()
ok
private
nLoadModel = 0
Class ControllerBase

nRecordsPerPage = 5
nRecordsCount = 0
nPagesCount = 0
nActivePage = 0
# Dynamic creation of oView = new tablenameView and oModel = new tablename.Model
classname = lower(classname(self))
if right(classname,10) = :controller
tablename = left(classname,len(classname)-10)
cCode = "oView = new " + tablename+"View" + nl
cCode += "oModel = new " + tablename+"Model" + nl
eval(cCode)
oModel.connect()
ok
cSearchName = "searchname"
cPart = "part"
cPageError = "The page number is not correct"
cLast = "last"
cOperation = "operation"
cRecID = "recid"
aColumnsNames = ["id"]
for t in oModel.aColumns
aColumnsNames + t
next
cMainURL = website + "?"
func Routing
switch aPageVars[cOperation]
on NULL showtable()
on :add addrecord()
on :save saverecord()
on :delete deleterecord()
on :edit editrecord()
on :update updaterecord()
off
func ShowTable
nRecordsCount = oModel.Count( aPageVars[cSearchName] )
nPagesCount = ceil(nRecordsCount / nRecordsPerPage)
if aPageVars[cPart] = cLast
aPageVars[cPart] = string(nPagesCount)
ok
nActivePage = number(aPageVars[cPart])
if nActivePage = 0 nActivePage = 1 ok
if ( nActivePage > nPagesCount ) and nRecordsCount > 0
ErrorMsg(cPageError)
return
ok

nStart = (nActivePage-1)*nRecordsPerPage
if aPageVars[cSearchName] = NULL
oModel.Read( nStart,nRecordsPerPage )
else
oModel.Search( aPageVars[cSearchName],nStart,nRecordsPerPage )
ok
oView.GridView(self)
func AddRecord
oModel.clear()
oView.FormViewAdd(Self,:save,false) # false mean don't include record id
func SaveRecord
oModel.Insert()
oView.SaveView(self)
func EditRecord
oModel.Find( aPageVars[cRecID] )
oView.FormViewEdit(Self,:update,true) # true mean include record id
func UpdateRecord
oModel.update( aPageVars[cRecID] )
oView.UpdateView(self)
func DeleteRecord
oModel.Delete( aPageVars[cRecID] )
oView.DeleteView()
func braceend
oModel.Disconnect()
48.24 WebLib API
In this section we will see the web library functions, classes and methods.
Function Parameters Description
LoadVars None Save the request parameters and cookies to aPageVars List
WebPage None Create new object from the WebPage Class
BootStrapWebPage None Create new object from the BootStrapWebPage Class
HTMLSpecialChars cString Encode Special characters to HTML equivalent
Template cFile,oObject Execute Ring Code in cFile after accessing oObject using {}
Alert cMessage Generate HTML Web Page that display cMessage using JavaScript Alert()
HTML2PDF cString Generate and Display PDF File from HTML String (cString)
The Package System.Web contains the next classes
48.24. WebLib API 394

Class Name Description
Application Contains methods for Encoding, Decoding, Cookies & More.
Page Contains methods to generate HTML pages.
ScriptFunctions Contains methods to generate some JavaScript Functions.
StyleFunctions Contains methods to generate CSS.
PageBuffer Generate HTML Page in memory (don’t print the output).
HTML2PDF Generate PDF File from HTML code.
BootStrapPage Using BootStrap Library.
WebPage Generate page using objects for each element.
HtmlPage Like WebPage but doesn’t print the output to stdout.
BootStrapWebPage Generate page using objects, using BootStrap Library.
ObjsBase Parent Class for page objects.
NewObjectsFunctions Methods to create new objects in the page or element.
H1 Wraps HTML H1.
H2 Wraps HTML H2.
H3 Wraps HTML H3.
H4 Wraps HTML H4.
H5 Wraps HTML H5.
H6 Wraps HTML H6.
P Wraps HTML P.
Link Wraps HTML link.
NewLine Wraps HTML NewLine.
Div Wraps HTML Div.
Form Wraps HTML Form.
Input Wraps HTML Input.
TextArea Wraps HTML TextArea.
Select Wraps HTML Select.
Option Wraps HTML Option.
Image Wraps HTML Image.
UL Wraps HTML UL.
LI Wraps HTML LI.
Table Wraps HTML Table.
TR Wraps HTML TR.
TD Wraps HTML TD.
TH Wraps HTML TH.
Audio Wraps HTML Audio.
Video Wraps HTML Video.
Nav Wraps HTML Nav.
Span Wraps HTML Span.
Button Wraps HTML Button.
48.24. WebLib API 395

48.25 Application Class
Method Parameters Description
DecodeString cString Decode request parameters
Decode cString Decode multipart/form-data
GetFileName aArray,cVar Get File Name in aArray using cVar
SetCookie name,value,expires,path,domain,secure Set Cookie
Cookie name,value Set Cookie using name and value only
GetCookies None Get Cookies
URLEncode cString URL Encode
ScriptLibs None Add JavaScript Libraries like BootStrap
Print None Print Page Content
Style cStyle Add cStyle to page CSS content
StartHTML None Add HTTP Header to page content
The method DecodeString is used to get HTTP request parameters.
The methods Decode and GetFileName are used for uploading ﬁles.
The methods SetCookie, Cookie & GetCookies are used for adding and reading cookies.
The methods StartHTML, ScriptsLibs, Style & Print are used for page structure and JS/CSS support.
The method URLEncode is used to encode a URL to be used in HTML pages.
48.26 Page Class
text x add HTMLSpecialChars(x) to page content (accept strings and numbers)
html cString add html code to page content
h1 x add x to page content between <h1> and </h1>
p aPara HTML <p> </p>, uses aPara List as Hash to get attributes
NewLine None add <br /> to page content
AddAttributes aPara Convert aPara list as hash to HTML element attributes
Link aPara HTML <a href> and </a>, uses aPara List as Hash to get attributes
Image aPara HTML <img>, uses aPara List as Hash to get attributes
Button aPara HTML <input type=”button”>, uses aPara List as Hash to get attributes
ButtonLink aPara HTML <input type=”button”>, uses link attribute to navigate to link
Textbox aPara HTML <input type=”text”>, uses aPara List as Hash to get attributes
Editbox aPara HTML <textarea> and </textarea>, uses aPara to get attributes
Combobox aPara HTML <select>, uses items attribute as list for <option>
Listbox aPara HTML <select multiple=’multiple’>, uses items attribute for <option>
ulstart aPara HTML <ul>
ulend aPara HTML </ul>
listart aPara HTML <li>
liend aPara HTML </li>
Continued on next page
48.25. Application Class 396

Table 48.2 – continued from previous page
List2UL aList Generate HTML <ul> including items from Ring List items
DivStart aPara HTML <div>, uses aPara List as Hash to get attributes
NavStart aPara HTML <nav>, uses aPara List as Hash to get attributes
SpanStart aPara HTML <span>, uses aPara List as Hash to get attributes
BoxStart None Generate Div with black background to be used as page header
DivEnd None HTML </div>
NavEnd None HTML </nav>
SpanEnd None HTML </span>
BoxEnd None HTML </div>, the same as divend()
FormStart cAction HTML <form>, with cAction as the action attribute or an empty value
FormPost cAction HTML <form method=”post”> , with cAction as the action attribute
FormEnd None HTML </form>
Submit aPara HTML <input type=”submit”>
Hidden cName,cValue HTML <input type=”hidden”>
FormUpload x HTML Form, method=”post” enctype=”multipart/form-data” and x = action
UploadFile x HTML <input type=”ﬁle”> and name = x
Video aPara HTML <video>
Audio aPara HTML <audio>
GetColor aPara Select Color
Radio aPara HTML <input type=”radio”>
Checkbox aPara HTML <input type=”checkbox”>
Spinner aPara HTML <input type=”number”>
Slider aPara HTML <input type=”range”>
TableStart aPara HTML <table>
TableEnd None HTML </table>
RowStart aPara HTML <tr>
RowEnd None HTML </tr>
CellStart aPara HTML <td>
CellEnd None HTML </td>
HeaderStart aPara HTML <th>
HeaderEnd None HTML </th>
aPara in the page methods is a list contains attributes and values. Using aPara we can set values for the next attributes
classname id name align style dir value onclick oncontextmenu ondblclick
onmousedown onmouseenter onmouseleave onmousemove onmouseover onmouseout
onmouseup onkeydown onkeypress onkeyup onabort onbeforeunload onerror
onhashchange onload onpageshow onpagehide onresize onscroll onunload
onblur onchange onfocus onfocusin onfocusout oninput oninvalid onreset
onsearch onselect onsubmit ondrag ondragend ondragenter ondragleave
ondragover ondragstart ondrop oncopy oncut onpaste onafterprint
onbeforeprint oncanplay oncanplaythrough ondurationchange onemptied
onended onloadeddata onloadedmetadata onloadstart onpause onplay
onplaying onprogress onratechange onseeked onseeking onstalled onsuspend
ontimeupdate onvolumechange onwaiting animationend animationiteration
animationstart transitionend onmessage onopen onmousewheel ononline
onoffline onpostate onshow onstorage ontoggle onwheel ontouchcancel
ontouchend ontouchmove ontouchstart color opacity background backgroundattachment
backgroundcolor backgroundimage backgroundposition backgroundrepeat backgroundclip
backgroundorigin backgroundsize border borderbottom borderbottomcolor
borderbottomleftradius borderbottomrightradius borderbottomstyle borderbottomwidth
bordercolor borderimage borderimageoutset borderimagerepeat borderimageslice
48.26. Page Class 397

borderimagesource borderimagewidth borderleft borderleftcolor borderleftstyle
borderleftwidth borderradius borderright borderrightcolor borderrightstyle
borderrightwidth borderstyle bordertop bordertopcolor bordertopleftradius
bordertoprightradius bordertopstyle bordertopwidth borderwidth boxdecorationbreak
boxshadow bottom clear clip display float height left margin marginbottom marginleft
marginright margintop maxheight maxwidth minheight minwidth overflow overflowx
overflowy padding paddingbottom paddingleft paddingright paddingtop position
right top visibility width verticalalign zindex aligncontent alignitems alignself
flex flexbasis flexdirection flexflow flexgrow flexshrink flexwrap justifycontent
order hangingpunctuation hyphens letterspacing linebreak lineheight overflowwrap
tabsize textalign textalignlast textcombineupright textindent textjustify
texttransform whitespace wordbreak wordspacing wordwrap textdecoration
textdecorationcolor textdecorationline textdecorationstyle textshadow
textunderlineposition @fontface @fontfeaturevalues font fontfamily fontfeaturesettings
fontkerning fontlanguageoverride fontsize fontsizeadjust fontstretch fontstyle
fontsynthesis fontvariant fontvariantalternates fontvariantcaps fontvarianteastasian
fontvariantligatures fontvariantnumeric fontvariantposition fontweight direction
textorientation unicodebidi writingmode bordercollapse borderspacing captionside
emptycells tablelayout counterincrement counterreset liststyle liststyleimage
liststyleposition liststyletype @keyframes animation animationdelay animationdirection
animationduration animationfillmode animationiterationcount animationname
animationplaystate animationtimingfunction backfacevisibility perspective
perspectiveorigin transform transformorigin transformstyle transition
transitionproperty transitionduration transitiontimingfunction transitiondelay
boxsizing content cursor imemode navdown navindex navleft navright navup
outline outlinecolor outlineoffset outlinestyle outlinewidth resize textoverflow
breakafter breakbefore breakinside columncount columnfill columngap columnrule
columnrulecolor columnrulestyle columnrulewidth columnspan columnwidth columns
widows orphans pagebreakafter pagebreakbefore pagebreakinside marks quotes
filter imageorientation imagerendering imageresolution objectfit objectposition
mask masktype mark markafter markbefore phonemes rest restafter restbefore
voicebalance voiceduration voicepitch voicepitchrange voicerate voicestress
voicevolume marqueedirection marqueeplaycount marqueespeed marqueestyle datatoggle
dataride datatarget dataslideto dataslide datadismiss dataplacement datacontent
datatrigger dataspy dataoffset dataoffsettop
48.27 ScriptFunctions Class
This class contains methods for adding JavaScript code to the generated web page.
The class methods are merged to the Page class, so we can use the next methods with page objects directly.
Script cCode Add cCode string between <script> and </script>
ScriptRedirec-
tion
cURL set window.location to cURL
ScriptFunc cFuncName,cCode Define function cFuncName that contains cCode
ScriptFuncAlert cFuncName,cMsg Define function cFuncName that uses alert() to print
cMsg
ScriptFuncAjax cFuncName,cLink,cDiv Define function cFuncName that load cLink in cDiv
ScriptFuncClean cFuncName,cDiv Define function cFuncName that clear the cDiv
ScriptFuncSe-
lect
cF,aL,cD,cR,cGR,cFC,nTO,cL1,cL2 Used to Edit/Delete Grid Record
ScriptScroll-
Fixed
cDiv,nSize Set cDiv as Fixed Div with Size = nSize
48.27. ScriptFunctions Class 398

48.28 StyleFunctions Class
This class contains methods for adding CSS to the generated web page.
Like ScriptFunctions Class, The StyleFunctions class methods are merged to the Page class, so we can use the next
methods with page objects directly.
StyleFloatLeft None Return float: left ;
StyleFloatRight None Return float: right ;
StyleSizeFull None Return width: 100% ; height: 100% ;
Stylecolor x Return ” color: ” + x + ” ; “
Stylebackcolor x Return ” background-color: ” + x + ” ;”
StyleTextCenter None Return “text-align: center ;”
StyleTextRight None Return “text-align: right ;”
StyleTextLeft None Return “text-align: left ;”
StyleSize x,y Return ” width: ” + x + ” ; height: ” + y + ” ;”
StyleWidth x Return ” width: ” + x + ” ;”
StyleHeight x Return ” height: ” + x + ” ;”
StyleTop x Return ” top: ” + x + ” ;”
StyleLeft x Return ” Left: ” + x + ” ;”
StylePos x,y Return ” top: ” + x + ” ;” + ” Left: ” + y + ” ;”
StyleHorizontalCenter None Return ” margin-right:auto ; margin-left:auto; “
StyleMarginTop x Return ” margin-top: ” + x + ” ;”
StyleMarginRight x Return ” margin-right: ” + x + ” ;”
StyleMarginLeft x Return ” margin-left: ” + x + ” ;”
StyleDivCenter nWidth,nHeight Create Div in the center of the page
StyleAbsolute None Return ” position:absolute ;”
StyleFixed None Return ” position:fixed ;”
StyleZIndex x Return ” z-index: ” + x + ” ;”
StyleFontSize x Return ” font-size: ” + x + ” ;”
StyleGradient x Generate Gradient (x values from 1 to 60)
StyleTable None Set table properties
StyleTableRows id Set different color to even and odd rows in the table
StyleTableNoBorder None Return ” border-style: none;”
48.29 WebPage Class
We use braces to access the active WebPage object attributes
Each one of these attribute will return a new object to access again using braces.
48.28. StyleFunctions Class 399

Attribute Description
H1 Wraps HTML H1.
H2 Wraps HTML H2.
H3 Wraps HTML H3.
H4 Wraps HTML H4.
H5 Wraps HTML H5.
H6 Wraps HTML H6.
P Wraps HTML P.
Link Wraps HTML link.
NewLine Wraps HTML NewLine.
Div Wraps HTML Div.
Form Wraps HTML Form.
Input Wraps HTML Input.
TextArea Wraps HTML TextArea.
Select Wraps HTML Select.
Option Wraps HTML Option.
Image Wraps HTML Image.
UL Wraps HTML UL.
LI Wraps HTML LI.
Table Wraps HTML Table.
TR Wraps HTML TR.
TD Wraps HTML TD.
TH Wraps HTML TH.
Audio Wraps HTML Audio.
Video Wraps HTML Video.
Nav Wraps HTML Nav.
Span Wraps HTML Span.
Button Wraps HTML Button.
48.30 HtmlPage Class
The same as the WebPage class with the next changes
1. No output to the stdout
2. Provide the Output Method to get the output
Syntax:
output() ---> The output as string
48.30. HtmlPage Class 400

CHAPTER
FORTYNINE
USING RINGLIBCURL
In this chapter we will learn about using RingLibCurl
49.1 Get Request
Example:
load "libcurl.ring"
curl = curl_easy_init()
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1)
curl_easy_setopt(curl, CURLOPT_URL, "http://ring-lang.sf.net")
curl_easy_perform(curl)
curl_easy_cleanup(curl)
49.2 Post Request
Example:
load "libcurl.ring"
cPostThis = "page=4&Number1=4&Number2=5"
curl_easy_setopt(curl, CURLOPT_URL, "http://localhost/ringapp/index.ring?page=3")
curl_easy_setopt(curl, CURLOPT_POSTFIELDS, cPostThis)
49.3 Facebook Login
Example:
401

load "libcurl.ring"
see "Enter Email : " give $login_email
See "Enter Password : " give $login_pass
curl_easy_setopt(curl, CURLOPT_URL, 'https://www.facebook.com/login.php')
curl_easy_setopt(curl, CURLOPT_POSTFIELDS,'charset_test=j u s t a t e s t'+
' &email='+urlencode($login_email)+'&pass='+
urlencode($login_pass)+'&login=Login')
curl_easy_setopt(curl, CURLOPT_POST, 1)
curl_easy_setopt(curl, CURLOPT_HEADER, 0)
curl_easy_setopt(curl, CURLOPT_COOKIEJAR, "cookies.txt")
curl_easy_setopt(curl, CURLOPT_COOKIEFILE, "cookies.txt")
curl_easy_setopt(curl, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U;"+
" Windows NT 5.1; en-US; rv:1.8.1.3) Gecko/20070309 Firefox/2.0.0.3")
curl_easy_setopt(curl, CURLOPT_REFERER, "http://www.facebook.com")
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, FALSE)
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 2)
mylist = curl_slist_append(NULL,'Accept-Charset: utf-8')
curl_slist_append(mylist,'Accept-Language: en-us,en;q=0.7,bn-bd;q=0.3')
curl_slist_append(mylist,'Accept: text/xml,application/xml,'+
'application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5')
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, mylist)
curl_easy_setopt(curl, CURLOPT_COOKIESESSION, false)
Func URLEncode cStr
cOut = ""
for x in cStr
if isalnum(x)
cOut += x
but x = " "
cOut += "+"
else
cOut += "%"+str2hex(x)
ok
next
return cOut
49.4 Save Output to String
Example:
load "libcurl.ring"
49.4. Save Output to String 402

curl_easy_setopt(curl, CURLOPT_URL, "http://ring-lang.sf.net")
cOutput = curl_easy_perform_silent(curl)
See "Output:" + nl
see cOutput
49.5 Get Stock Data From Yahoo
Example:
Load "libcurl.ring"
### Part 1 --- Get Crumb and Cookie -----------------------------------------
See "Start curl_easy_init(): "+ nl
curl = curl_easy_init() ### >>> HANDLE >>> 01006BD0 CURL 0
curl_easy_setopt(curl, CURLOPT_COOKIEJAR, "cookies.txt")
curl_easy_setopt(curl, CURLOPT_COOKIEFILE, "cookies.txt")
curl_easy_setopt(curl, CURLOPT_URL, "https://finance.yahoo.com/quote/AMZN/history")
### HTML Data >>> STDOUT Window, Use curl_easy_perform_silent >>> String
cOutput = curl_easy_perform_silent(curl) ### GO Get Data >>> String
### Extract Crumb from data
### "CrumbStore":{"crumb":"abcdefghijk"},
if cOutput != NULL
newStr1 = substr(cOutput, substr(cOutput, '"CrumbStore":{"crumb":"' ), 48 )
nPosS = substr(newStr1, ':"' ) ; ### Start of crumb -2
nPosE = substr(newStr1, '"}' ) ; ### End of crumb
nCount = nPosE - nPosS -2 ### size of crumb
myCrumb = substr(newStr1, nPosS +2, nCount)
See "myCrumb.: |"+ myCrumb +"|" +nl
### UniCode "u002F" replace it with "/"
if substr( myCrumb, "u002F")
myCrumb = substr( myCrumb, "u002F", "/")
See "myCrumb2: |"+ myCrumb +"|"+ nl
ok
else
See "No Connectivity to Yahoo. Looking for Cookie and Crumb." +nl +nl
ok
### Part 2 --- Send URL with Crumb, and Cookie -----------------------------------------
49.5. Get Stock Data From Yahoo 403

### Send URL+Crumb to Yahoo to fetch 1st stock history data,
$url = "https://query1.finance.yahoo.com/v7/finance/download/AMZN?period1=1277856000&period2=
curl_easy_setopt(curl, CURLOPT_URL, $url);
cStr = curl_easy_perform_silent(curl)
See cStr
curl_easy_cleanup(curl) ### REMEMBER to CLOSE CURL
Output:
myCrumb.: |sEEeW97mxvN|
Date,Open,High,Low,Close,Adj Close,Volume
2010-07-05,110.650002,117.480003,109.000000,117.260002,117.260002,21000400
2010-07-12,117.809998,124.879997,117.320000,118.489998,118.489998,29407300
2010-07-19,118.379997,121.250000,105.800003,118.870003,118.870003,74252100
49.5. Get Stock Data From Yahoo 404

CHAPTER
FIFTY
USING RINGZIP
In this chapter we will learn about using RingZip
50.1 Create Zip File
Example : Create myfile.zip contains 4 files
load "ziplib.ring"
oZip = zip_openfile("myfile.zip",'w')
zip_addfile(oZip,"test.c")
zip_addfile(oZip,"zip.c")
zip_addfile(oZip,"zip.h")
zip_addfile(oZip,"miniz.h")
zip_close(oZip)
50.2 Extract Zip File
Example : Extract myfile.zip to myfolder folder.
load "ziplib.ring"
zip_extract_allfiles("myfile.zip","myfolder")
50.3 Print Files in Zip file
Example : Print file names in the myfile.zip
load "ziplib.ring"
oZip = zip_openfile("myfile.zip",'r')
for x=1 to zip_filescount(oZip)
see zip_getfilenamebyindex(oZip,x) + nl
next
zip_close(oZip)
50.4 Using RingZip Classes
The RingZip library comes with two classes. The Zip class and the ZipEntry class.
405

Example (1):
load "ziplib.ring"
new Zip {
setFileName("myfile.zip")
open("w")
newEntry() {
open("test.c")
writefile("test.c")
close()
}
close()
}
Example (2):
load "ziplib.ring"
new Zip {
SetFileName("myfile.zip")
Open("w")
AddFile("test.c")
AddFile("zip.c")
AddFile("zip.h")
AddFile("miniz.h")
Close()
}
Example (3):
load "ziplib.ring"
new zip {
ExtractAllFiles("myfolder")
}
Example (4):
load "ziplib.ring"
new Zip {
Open("r")
see FilesCount()
Close()
}
Example (5):
load "ziplib.ring"
new Zip {
Open("r")
for x = 1 to filescount()
See GetFileNameByIndex(x) + nl
next
Close()
50.4. Using RingZip Classes 406

}
50.5 Zip Class Reference
Methods:
Method Description/Output
SetFileName(cName) Set the Zip file name
GetFileName() Return the Zip file name
Open(cMode) Open File, cMode = “a”, “w” or “r”
Close() Close the Zip File
AddFile(cFileName) Add file to the Zip file
ExtractAllFiles(cFolder) Extract all files from the Zip file
FilesCount() Return files count in the Zip file
GetFileNameByIndex(nIndex) Return file name in the Zip file by file index
NewEntry() Create new ZipEntry object
50.6 ZipEntry Class Reference
Methods:
Method Description/Output
Open(cFileName) Open new Entry
WriteFile(cFileName) Write File to the Entry
WriteString(cString) Write String to the Entry
Close() Close the Entry
50.5. Zip Class Reference 407

CHAPTER
FIFTYONE
GRAPHICS AND 2D GAMES PROGRAMMING USING RINGALLEGRO
In this chapter we will learn how to use the allegro game programming library in our Ring applications.
We have the file gamelib.ring that load the DLL library that contains wrappers for the Allegro functions
Load "allegro.rh"
Loadlib("ring_allegro.dll")
The file gamelib.ring uses the Load instruction to execute the file allegro.rh which is a ring source code file con-
tains constants to be used in our programs. Then using the function LoadLib() we can load the DLL library
“ring_allegro.dll”.
To write portable code we can change the gamelib.ring to check the platform before loading the DLL/So file.
51.1 Drawing, Animation and Input
The next example uses the Allegro library for drawing, moving objects on the screen and getting input from the
keyboard and the mouse.
Load "gamelib.ring"
al_init()
al_init_image_addon()
display = al_create_display(640,480)
al_show_native_message_box(display, "Hello", "Welcome",
"Using Allegro from the Ring programming language",
"", 0);
al_clear_to_color(al_map_rgb(0,0,255))
BOUNCER_SIZE = 40
bouncer_x = 10
bouncer_y = 20
bouncer = al_create_bitmap(BOUNCER_SIZE, BOUNCER_SIZE)
al_set_target_bitmap(bouncer)
for x = 1 to 30
bouncer_x += x
bouncer_y += x
al_set_target_bitmap(al_get_backbuffer(display))
408

al_draw_bitmap(bouncer, bouncer_x, bouncer_y, 0)
al_draw_bitmap(bouncer, 200+bouncer_x,200+ bouncer_y, 0)
al_flip_display()
al_rest(0.1)
next
image = al_load_bitmap("man2.jpg")
al_draw_bitmap(image,200,200,0)
al_flip_display()
al_rest(2)
event_queue = al_create_event_queue()
al_register_event_source(event_queue, al_get_display_event_source(display))
ev = al_new_allegro_event()
timeout = al_new_allegro_timeout()
al_init_timeout(timeout, 0.06)
FPS = 60
timer = al_create_timer(1.0 / FPS)
al_register_event_source(event_queue, al_get_timer_event_source(timer))
al_start_timer(timer)
redraw = true
SCREEN_W = 640
SCREEN_H = 480
BOUNCER_SIZE = 32
bouncer_x = SCREEN_W / 2.0 - BOUNCER_SIZE / 2.0
bouncer_y = SCREEN_H / 2.0 - BOUNCER_SIZE / 2.0
bouncer_dx = -4.0
bouncer_dy = 4.0
al_install_mouse()
al_register_event_source(event_queue, al_get_mouse_event_source())
al_install_keyboard()
al_register_event_source(event_queue, al_get_keyboard_event_source())
KEY_UP = 1
KEY_DOWN = 2
KEY_LEFT = 3
KEY_RIGHT = 4
Key = [false,false,false,false]
while true
al_wait_for_event_until(event_queue, ev, timeout)
switch al_get_allegro_event_type(ev)
on ALLEGRO_EVENT_DISPLAY_CLOSE
exit
on ALLEGRO_EVENT_TIMER
# Animation
if bouncer_x < 0 or bouncer_x > SCREEN_W - BOUNCER_SIZE
bouncer_dx = -bouncer_dx
ok
if bouncer_y < 0 or bouncer_y > SCREEN_H - BOUNCER_SIZE
51.1. Drawing, Animation and Input 409

bouncer_dy = -bouncer_dy
ok
bouncer_x += bouncer_dx
bouncer_y += bouncer_dy
# Keyboard
if key[KEY_UP] and bouncer_y >= 4.0
bouncer_y -= 4.0
ok
if key[KEY_DOWN] and bouncer_y <= SCREEN_H - BOUNCER_SIZE - 4.0
bouncer_y += 4.0
ok
if key[KEY_LEFT] and bouncer_x >= 4.0
bouncer_x -= 4.0
ok
if key[KEY_RIGHT] and bouncer_x <= SCREEN_W - BOUNCER_SIZE - 4.0
bouncer_x += 4.0
ok
redraw = true
on ALLEGRO_EVENT_MOUSE_AXES
bouncer_x = al_get_allegro_event_mouse_x(ev)
bouncer_y = al_get_allegro_event_mouse_y(ev)
on ALLEGRO_EVENT_MOUSE_ENTER_DISPLAY
bouncer_x = al_get_allegro_event_mouse_x(ev)
bouncer_y = al_get_allegro_event_mouse_y(ev)
on ALLEGRO_EVENT_MOUSE_BUTTON_UP
exit
on ALLEGRO_EVENT_KEY_DOWN
switch al_get_allegro_event_keyboard_keycode(ev)
on ALLEGRO_KEY_UP
key[KEY_UP] = true
on ALLEGRO_KEY_DOWN
key[KEY_DOWN] = true
on ALLEGRO_KEY_LEFT
key[KEY_LEFT] = true
on ALLEGRO_KEY_RIGHT
key[KEY_RIGHT] = true
off
on ALLEGRO_EVENT_KEY_UP
switch al_get_allegro_event_keyboard_keycode(ev)
on ALLEGRO_KEY_UP
key[KEY_UP] = false
on ALLEGRO_KEY_DOWN
key[KEY_DOWN] = false
on ALLEGRO_KEY_LEFT
key[KEY_LEFT] = false
on ALLEGRO_KEY_RIGHT
key[KEY_RIGHT] = false
on ALLEGRO_KEY_ESCAPE
exit
off
off
if redraw and al_is_event_queue_empty(event_queue)
redraw = false

al_draw_bitmap(bouncer, bouncer_x, bouncer_y, 0)
al_flip_display()
ok
callgc()
end
al_destroy_timer(timer)
al_destroy_allegro_event(ev)
al_destroy_allegro_timeout(timeout)
al_destroy_event_queue(event_queue)
al_destroy_bitmap(bouncer)
al_destroy_bitmap(image)
al_destroy_display(display)
Note: In the previous example we used the function callgc() which is a Ring function to force calling the Garbage
collector inside the While/End loop.
Program Output:
At ﬁrst the program display a messagebox
Then we see two rectangles are moving on the screen

Then we see an image displayed on the screen

Finally we have one rectangle, and we see it moving all of the time on the screen but we can control it using the Mouse
and/or the Keyborad

51.2 Using TrueType Fonts
In this example we will see how to use TrueType Fonts *.ttf in our Games using Allegro
Load "gamelib.ring"
al_init()
al_init_font_addon()
al_init_ttf_addon()
font = al_load_ttf_font("pirulen.ttf",14,0 )
al_draw_text(font, al_map_rgb(255,255,255), 10, 10,ALLEGRO_ALIGN_LEFT,
"Welcome to the Ring programming language")
al_flip_display()
al_rest(2)
Screen Shot:
51.2. Using TrueType Fonts 414

51.3 Playing Sound Files
The next example play a sound ﬁle
Load "gamelib.ring"
al_init()
al_install_audio()
al_init_acodec_addon()
al_reserve_samples(1)
sample = al_load_sample( "footstep.wav" )
sampleid = al_new_allegro_sample_id()
al_play_sample(sample, 1.0, 0.0,1.0,ALLEGRO_PLAYMODE_LOOP,sampleid)
al_flip_display()
al_rest(10)
al_destroy_allegro_sample_id(sampleid)
51.3. Playing Sound Files 415

al_destroy_sample(sample)
al_exit()
51.4 Scaling and Rotating Images
The next example display and rotate an image
Load "gamelib.ring"
al_init()
al_set_target_bitmap(al_get_backbuffer(display))
image = al_load_bitmap("man2.jpg")
al_draw_rotated_bitmap(image,0,0,250,250,150,0)
al_draw_scaled_bitmap(image,0,0,250,250,20,20,400,400,0)
al_flip_display()
al_rest(2)
Screen Shot:
51.4. Scaling and Rotating Images 416

51.5 Display Transparent Image
The next example display image with white background on another image
Load "gamelib.ring"
al_init()
imageback = al_load_bitmap("palace.jpg")
al_draw_bitmap(imageback,0,0,0)
image = al_load_bitmap("man4.png")
al_convert_mask_to_alpha(image,al_map_rgb(255,255,255))
al_draw_bitmap(image,0,0,0)
al_flip_display()
al_rest(10)
51.5. Display Transparent Image 417

Screen Shot:
51.6 Using Threads
In this example we will learn how to use threads from the Allegro library
Load "gamelib.ring"
o1 = new mythreads
Func Main
al_init()
for k = 1 to 5
al_create_thread("o1.thread1()")
next
al_rest(2)
Class Mythreads
cAppName = "Threads Application"
51.6. Using Threads 418

Func Thread1
for x = 1 to 5
see x + nl
next
See 'Thread(1) : Application Name : ' + cAppName + nl
Func Thread2
for x = 1 to 5
see '*****' + x + nl
next
Func Thread3
for x = 1 to 5
see '!!!!' + x + nl
next
Output:
1
2
3
4
5
Thread(1) : Application Name : Threads Application
*****1
*****2
*****3
*****4
*****5
!!!!1
!!!!2
!!!!3
!!!!4
!!!!5
1
2
3
4
5
!!!!1
!!!!2
!!!!3
!!!!4
!!!!5
*****1
*****2
*****3
*****4
*****5
*****1
*****2

*****3
*****4
*****5
!!!!1
!!!!2
!!!!3
!!!!4
!!!!5
1
2
3
4
5
*****1
*****2
*****3
*****1
*****4
*****2
!!!!1
*****5
*****3
1
!!!!2
1
*****4
!!!!1
2
!!!!3
!!!!4
*****5
!!!!2
3
2
!!!!5
!!!!3
4
3
!!!!4
5
4
!!!!5
5

CHAPTER
FIFTYTWO
USING RINGLIBSDL
In this chapter we will learn about using RingLibSDL to create games based on the LibSDL, SDLImage, SDLTTF and
SDLMixer libraries.
Tip: RingLibSDL is not distributed with the binary releases for desktop which uses RingAllegro
Note: To use RingLibSDL, Check ring/android/ringlibsdl folder.
52.1 Create Window
Example:
Load "libsdl.ring"
SDL_Init(SDL_INIT_EVERYTHING)
win = SDL_CreateWindow("Hello World!", 100, 100, 640, 480, SDL_WINDOW_SHOWN)
SDL_Delay(2000)
SDL_DestroyWindow(win)
SDL_Quit()
52.2 Display Image
Example:
Load "libsdl.ring"
ren = SDL_CreateRenderer(win, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC )
bmp = SDL_LoadBMP("hello.bmp")
tex = SDL_CreateTextureFromSurface(ren,bmp)
SDL_FreeSurface(bmp)
SDL_RenderClear(ren)
SDL_RenderCopy2(ren,tex)
SDL_RenderPresent(ren)
SDL_Delay(2000)
SDL_DestroyTexture(tex)
SDL_DestroyRenderer(ren)
SDL_Quit()
421

52.3 Switch between two images
Example:
Load "libsdl.ring"
bmp = SDL_LoadBMP("hello.bmp")
bmp = SDL_LoadBMP("hello2.bmp")
tex2 = SDL_CreateTextureFromSurface(ren,bmp)
for x = 1 to 10 showtex(tex) showtex(tex2) next
SDL_DestroyTexture(tex2)
SDL_Quit()
func showtex oTex
SDL_RenderCopy2(ren,oTex)
SDL_Delay(200)
52.4 Draw Rectangle
Example:
Load "libsdl.ring"
rect = sdl_new_sdl_rect()
sdl_set_sdl_rect_x(rect,10)
sdl_set_sdl_rect_y(rect,10)
sdl_set_sdl_rect_w(rect,100)
sdl_set_sdl_rect_h(rect,100)
SDL_SetRenderDrawColor(ren,255,255,255,255)
SDL_RenderDrawRect(ren,rect)
sdl_destroy_sdl_rect(rect)
SDL_Delay(2000)
SDL_Quit()
52.3. Switch between two images 422

52.5 Display PNG Images
Example:
Load "libsdl.ring"
bmp = IMG_Load("hello3.png")
SDL_RenderCopy2(ren,tex)
SDL_Delay(2000)
SDL_Quit()
52.6 Use TTF Fonts
Example:
Load "libsdl.ring"
TTF_Init()
font = TTF_OpenFont("pirulen.ttf", 16)
color = sdl_new_sdl_color()
sdl_set_sdl_color_r(color,0)
sdl_set_sdl_color_g(color,255)
sdl_set_sdl_color_b(color,0)
text = TTF_RenderText_Solid(font,"Welcome to the Ring language",color)
surface = SDL_GetWindowSurface(win)
SDL_BlitSurface(text, nullpointer(), surface, nullpointer())
SDL_UpdateWindowSurface(win)
SDL_Delay(2000)
SDL_Destroy_SDL_Color(color)
SDL_FreeSurface(text)
TTF_CloseFont(font)
SDL_Quit()
52.7 Display Transparent Images
Example:
52.5. Display PNG Images 423

Load "libsdl.ring"
flags = IMG_INIT_JPG | IMG_INIT_PNG
IMG_Init(flags)
bmp = IMG_Load("stars.jpg")
SDL_RenderCopy(ren,tex,nullpointer(),nullpointer())
bmp = IMG_Load("player.png")
# Image - Set Transparent color (white)
myformat = sdl_get_sdl_surface_format(bmp)
white = SDL_MapRGB(myformat, 255, 255, 255)
SDL_SetColorKey(bmp, SDL_True, white)
rect = sdl_new_sdl_rect()
SDL_RenderCopy(ren,tex,nullpointer(),rect)
SDL_SetTextureBlendMode(tex,2)
SDL_SetTextureAlphaMod(tex,255)
SDL_RenderCopy(ren,tex,nullpointer(),rect)
SDL_Destroy_SDL_Rect(rect)
SDL_Delay(2000)
SDL_Quit()
52.8 Close Window Event
Example:
Load "libsdl.ring"
52.8. Close Window Event 424

myevent = sdl_new_sdl_event()
while true
thevent = sdl_pollevent(myevent)
switch sdl_get_sdl_event_type(myevent)
on sdl_get_sdl_quit()
exit
on sdl_get_sdl_keydown()
Key = SDL_GET_SDL_Event_key_keysym_sym(myevent)
if key = 27 exit ok
off
end
SDL_Quit()
52.9 Mouse Events
Example:
Load "libsdl.ring"
win = SDL_CreateWindow("Mouse Events ", 100, 100, 640, 480, SDL_WINDOW_SHOWN)
TTF_Init()
font = TTF_OpenFont("pirulen.ttf", 16)
color = sdl_new_sdl_color()
sdl_set_sdl_color_r(color,0)
sdl_set_sdl_color_g(color,255)
sdl_set_sdl_color_b(color,0)
surface = SDL_GetWindowSurface(win)
while true
cMsg = ""
sdl_pollevent(myevent)
on SDL_QUIT
exit
on SDL_KEYDOWN
if key = 27 exit ok
on SDL_MOUSEBUTTONDOWN
if sdl_get_Sdl_Event_button_button(myevent) = SDL_BUTTON_LEFT
SDL_SETWINDOWTITLE(win, " Button_Left_Down " )
but sdl_get_Sdl_Event_button_button(myevent) = SDL_BUTTON_MIDDLE
SDL_SETWINDOWTITLE(win, " Button_Middle_Down " )
but sdl_get_Sdl_Event_button_button(myevent) = SDL_BUTTON_RIGHT
SDL_SETWINDOWTITLE(win, " Button_Right_Down " )
ok
on SDL_MOUSEMOTION
52.9. Mouse Events 425

sdl_fillrect(surface,nullpointer(),0)
if sdl_get_sdl_event_motion_xrel(myevent) < 0
cMsg += " Left "
else
cMsg += " Right "
ok
if sdl_get_sdl_event_motion_yrel(myevent) < 0
cMsg += " Up "
else
cMsg += " Down "
ok
cMsg += " x = " + sdl_get_sdl_event_motion_x(myevent)
cMsg += " y = " + sdl_get_sdl_event_motion_y(myevent)
showmsg(cMsg)
off
end
SDL_Destroy_SDL_Color(Color)
TTF_CloseFont(font)
SDL_Quit()
func showmsg mymsg
text = TTF_RenderText_Solid(font,mymsg,color)
SDL_BlitSurface(text, nullpointer(), surface, nullpointer())
SDL_UpdateWindowSurface(win)
SDL_FreeSurface(text)
52.10 Play Sound
Example:
Load "libsdl.ring"
Mix_OpenAudio( 44100, MIX_DEFAULT_FORMAT , 2, 10000)
Mix_AllocateChannels(4)
sound = Mix_LoadWav( "sound.wav" )
Mix_VolumeChunk(sound,1)
Mix_PlayChannel(1,sound,0)
while true
thevent = sdl_pollevent(myevent)
on sdl_get_sdl_quit()
exit
on sdl_get_sdl_keydown()
if key = 27 exit ok
off
end
Mix_FreeChunk( sound )
Mix_CloseAudio()
52.10. Play Sound 426

Mix_Quit()
SDL_Quit()
52.10. Play Sound 427

CHAPTER
FIFTYTHREE
DEMO PROJECT - GAME ENGINE FOR 2D GAMES
In this chapter we will learn about using the different programming paradigms in the same project.
We will create a simple Game Engine for 2D Games.
You can use the Engine directly to create 2D Games for Desktop or Mobile.
53.1 Project Layers
The project contains the next layers
• Games Layer (Here we will use declarative programming)
• Game Engine Classes (Here we will use the Object-Oriented Programming paradigm)
• Interface to graphics library (Here we will use procedural programming)
• Graphics Library bindings (Here we have RingAllegro and RingLibSDL)
53.2 Graphics Library bindings
We already have RingAllegro to use the Allegro game programming library and we have RingLibSDL to use the
LibSDL game programming library.
Both of RingAllegro and RingLibSDL are created using the C language with the help of the Ring code generator for
extensions.
Each of them is over 10,000 lines of C code which is generated after writing simple configuration files (That are
processed by the code generator).
Each configuration file determines the functions names, structures information and constants then the generator process
this configuration file to produce the C code and the library that can be loaded from Ring code.
Using RingAllegro and RingLibSDL is very similar to using Allegro and LibSDL from C code where you have the
same functions but we can build on that using the Ring language features
• RingAllegro Source Code : https://github.com/ring-lang/ring/tree/master/extensions/ringallegro
• RingLibSDL Source Code : https://github.com/ring-lang/ring/tree/master/extensions/ringsdl
428

53.3 Interface to graphics library
In this layer we have gl_allegro.ring and gl_libsdl.ring
Each library provides the same functions to be used with interacting with the Graphics Library.
This layer hides the details and the difference between RingAllegro and RingLibSDL.
You have the same functions, Just use it and you can switch between Allegro and LibSDL at anytime.
Why ?
Allegro is very simple, we can use it to quickly create 2D games for Windows, Linux and MacOS X.
In Ring 1.0 we started by supporting Allegro.
Also LibSDL is very powerful and popular, very easy to use for Mobile Development.
Ring 1.1 comes with support for LibSDL so we can quickly create games for Mobile.
Note: We can use just one library for Desktop and Mobile development.
• gl_allegro.ring source code : https://github.com/ring-lang/ring/blob/master/ringlibs/gameengine/gl_allegro.ring
• gl_libsdl.ring source code : https://github.com/ring-lang/ring/blob/master/ringlibs/gameengine/gl_libsdl.ring
53.4 Game Engine Classes
The Engine comes with the next classes
• GameBase class
• Resources class
• Game class
• GameObject class
• Sprite class
• Text class
• Animate class
• Sound class
• Map class
• Source Code : https://github.com/ring-lang/ring/blob/master/ringlibs/gameengine/gameengine.ring
53.5 Games Layer
In this layer we create our games using the Game Engine classes
The classes are designed to be used through Declarative Programming.
In our games we will use the next classes
• Game class
• Sprite class
53.3. Interface to graphics library 429

• Text class
• Animate class
• Sound class
• Map class
Note: Other classes in the engine are for internal use by the engine.
We will introduce some examples and three simple games :-
• Stars Fighter Game
• Flappy Bird 3000 Game
• Super Man 2016 Game
53.6 Game Class
The next table present the class attributes.
Attributes Description
FPS Number determines how many times the draw() method will be called per second.
FixedFPS Number determines how many times the animate() method will be called per second.
Title String determines the window title of the game.
aObjects List contains all objects in the game
shutdown True/False value to end the game loop
The next table present the class methods.
Method Description
refresh() Delete objects.
settitle(cTitle) Set the window title using a string parameter.
shutdown() Close the application.
The next table present a group of keywords deﬁned by the class.
Keyword Description
sprite Create new Sprite object and add it to the game objects.
text Create new Text object and add it to the game objects.
animate Create new Animate object and add it to the game objects.
sound Create new Sound object and add it to the game objects.
map Create new Map object and add it ot the game objects.
53.7 GameObject Class
53.6. Game Class 430

enabled True/False determine the state of the object (Active/Not Active)
x Number determine the x position of the object.
y Number determine the y position of the object.
width Number determine the width of the object.
height Number determine the height of the object.
nIndex Number determine the index of the object in objects list.
animate True/False to animate the object or not.
move True/False to move the object using the keyboard or not.
Scaled True/False to scale the object image or not.
draw Function to be called when drawing the object.
state Function to be called for object animation.
keypress Function to be called when a key is pressed.
mouse Function to be called when a mouse event happens.
Method Description
keyboard(oGame,nkey) Check Keyboard Events
mouse(oGame,nType,aMouseList) Check Mouse Events
rgb(r,g,b) Return new color using the RGB (Red, Green and Blue) Values.
53.8 Sprite Class
Parent Class : GameObject Class
image String determine the image ﬁle name.
point Number determine the limit of automatic movement of the object.
direction Number determine the direction of movement.
nstep Number determine the increment/decrement during movement.
type Number determine the object type in the game (Optional).
transparent True/False value determine if the image is transparent.
Method Description
Draw(oGame) Draw the object
53.9 Text Class
Parent Class : Sprite Class
size Number determine the font size
font String determine the font ﬁle name
text String determine the text to be displayed
color Number determine the color
53.8. Sprite Class 431

Method Description
53.10 Animate Class
frames Number determine the number of frames
frame Number determine the active frame
framewidth Number determine the frame width.
animate True/False determine using animate or not.
scaled True/False determine scaling image or not.
Method Description
53.11 Sound Class
Parent Class : GameObject Class
file String determine the sound file name.
once True/False determine to play the file one time or not (loop).
Method Description
playsound() Play the sound file
53.12 Map Class
aMap List determine the map content using numbers.
aImages List determine the image used for each number in the map.
BlockWidth Number determine the block width (default = 32).
BlockHeight Number determine the block height (default = 32).
Animate True/False determine the animation status.
Method Description
getvalue(x,y) Return the item value in the Map according to the visible part
53.10. Animate Class 432

53.13 Using the Game Engine - Creating the Game Window
Load "gameengine.ring" # Give Control to the Game Engine
func main # Called by the Game Engine
oGame = New Game # Create the Game Object
{
title = "My First Game"
} # Start the Events Loop
Note: if you want to deﬁne global variables, this must be before load “gameengine.ring” because this instruction will
give the control to the game engine.
Screen Shot:
53.14 Using the Game Engine - Drawing Text
53.13. Using the Game Engine - Creating the Game Window 433

{
text {
x = 10 y=50
animate = false
size = 20
file = "fonts/pirulen.ttf"
text = "game development using ring is very fun!"
color = rgb(0,0,0)
}
Screen Shot:
53.15 Using the Game Engine - Moving Text
53.15. Using the Game Engine - Moving Text 434

{
text {
x = 10 y=50
animate = false
size = 20
color = rgb(0,0,0) # Color = black
}
text {
x = 10 y=150
# Animation Part =====================================
animate = true # Use Animation
direction = GE_DIRECTION_INCVERTICAL # Increase y
point = 400 # Continue until y=400
nStep = 3 # Each time y+= 3
#=====================================================
size = 20
text = "welcome to the real world!"
color = rgb(0,0,255) # Color = Blue
}
Screen Shot:
53.15. Using the Game Engine - Moving Text 435

53.16 Using the Game Engine - Playing Sound
{
text {
x = 10 y=50
animate = false
size = 20
color = rgb(0,0,0) # Color = black
}
text {
x = 10 y=150
# Animation Part ======================================
animate = true # Use Animation
direction = GE_DIRECTION_INCVERTICAL # Increase y
53.16. Using the Game Engine - Playing Sound 436

point = 400 # Continue until y=400
nStep = 3 # Each time y+= 3
#======================================================
size = 20
text = "welcome to the real world!"
color = rgb(0,0,255) # Color = Blue
}
Sound { # Play Sound
file = "sound/music1.wav" # Sound File Name
}
53.17 Using the Game Engine - Animation
{
animate {
file = "images/fire.png"
x = 100
y = 200
framewidth = 40
height = 42
nStep = 3 # Used for delay
transparent = true
state = func oGame,oSelf { # Called by engine each frame
oSelf {
nStep--
if nStep = 0
nStep = 3
if frame < 13 # we have 13 frames in animation
frame++ # move to next frame
else
oGame.remove(oself.nIndex) # remove object
ok
ok
}
}
}
53.17. Using the Game Engine - Animation 437

53.18 Using the Game Engine - Animation and Functions
{
for x = 70 to 700 step 50
for y = 70 to 500 step 50
showfire(oGame,x,y)
next
next
func showfire oGame,nX,nY
oGame {
animate {
file = "images/fire.png"
x = nX
53.18. Using the Game Engine - Animation and Functions 438

y = nY
framewidth = 40
height = 42
nStep = 3 # Used for delay
transparent = true
state = func oGame,oSelf { # Called by engine each frame
oSelf {
nStep--
if nStep = 0
nStep = 3
if frame < 13 # we have 13 frames in animation
frame++ # move to next frame
else
frame=1
ok
ok
}
}
}
}
53.18. Using the Game Engine - Animation and Functions 439

53.19 Using the Game Engine - Sprite - Automatic Movement using
Keyboard
Load "gameengine.ring" # Give control to the game engine
{
sprite
{
type = GE_TYPE_PLAYER # Just for our usage
x=400 y=400 width=100 height=100
file = "images/player.png"
transparent = true
Animate=false
Move=true # we can move it using keyboard arrows
Scaled=true
}
53.19. Using the Game Engine - Sprite - Automatic Movement using Keyboard 440

53.20 Using the Game Engine - Sprite - Keypress event
{
sprite
{
transparent = true
Animate=false
Move=false # Custom Movement
Scaled=true
keypress = func oGame,oSelf,nKey {
oSelf {
Switch nKey
on KEY_LEFT
x -= 10
on KEY_RIGHT
x += 10
on KEY_UP
y -= 10
on KEY_DOWN
y += 10
off
}
}
}
53.21 Using the Game Engine - Sprite - Mouse event
{
sprite
{
transparent = true
Animate=false
Scaled=true
oSelf {
53.20. Using the Game Engine - Sprite - Keypress event 441

Switch nKey
on KEY_LEFT
x -= 10
on KEY_RIGHT
x += 10
on KEY_UP
y -= 10
on KEY_DOWN
y += 10
off
}
}
mouse = func oGame,oSelf,nType,aMouseList {
if nType = GE_MOUSE_UP
oSelf {
x = aMouseList[GE_MOUSE_X]
y = aMouseList[GE_MOUSE_Y]
}
ok
}
}
53.22 Using the Game Engine - Sprite - State event
{
sprite
{
transparent = true
Animate=false
Scaled=true
oSelf {
Switch nKey
on KEY_LEFT
x -= 10
on KEY_RIGHT
x += 10
on KEY_UP
y -= 10
on KEY_DOWN
y += 10
off
}
}
mouse = func oGame,oSelf,nType,aMouseList {
53.22. Using the Game Engine - Sprite - State event 442

oSelf {
x = aMouseList[GE_MOUSE_X]
y = aMouseList[GE_MOUSE_Y]
}
ok
}
state = func oGame,oSelf {
oself {
if x < 0 x = 0 ok
if y < 0 y = 0 ok
if x > ogame.width-width
x= ogame.width - width ok
if y > ogame.height-height
y=ogame.height - height ok
}
}
}
53.23 Using the Game Engine - Animate - Events
{
animate {
file = "images/fbbird.png"
x = 10
y = 10
framewidth = 20
scaled = true
height = 50
width = 50
nStep = 3
transparent = true
oSelf {
# Animation
nStep--
if nStep = 0
nStep = 3
if frame < 3
frame++
else
frame=1
ok
ok
53.23. Using the Game Engine - Animate - Events 443

# Move Down
y += 3
if y > 550 y=550 ok
}
}
keypress = func ogame,oself,nKey {
oself {
if nkey = key_space
y -= 55
if y<=0 y=0 ok
ok
}
}
mouse = func ogame,oself,nType,aMouseList {
cFunc = oself.keypress
call cFunc(oGame,oSelf,Key_Space)
ok
}
}
Screen Shot:
53.23. Using the Game Engine - Animate - Events 444

53.24 Using the Game Engine - Map
{
Map {
blockwidth = 80
blockheight = 80
aMap = [
[0,0,0,0,0,0,0,0,0,1,0,0,0,3,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0],
[0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0],
[0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,2,0,0,0,1,0,0,0],
[0,0,0,0,0,0,0,0,0,1,0,0,0,2,0,0,0,3,0,0,0,1,0,0,0,1,0,0,0],
[0,0,0,0,0,0,0,0,0,3,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,3,0,0,0],
[0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0],
53.24. Using the Game Engine - Map 445

[0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0]
]
aImages = ["images/fbwall.png",
"images/fbwallup.png",
"images/fbwalldown.png"]
oSelf {
x -= 3
if x < - 2100 x = 0 ok
}
}
}
Screen Shot:
53.24. Using the Game Engine - Map 446

The Ring programming language version 1.5 book - Part 8 of 31

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The Ring programming language version 1.5 book - Part 8 of 31