BrightScript provides XML support with two BrightScript objects and a set of dedicated language features:
roXMLElement: This object provides support for parsing, generating, and containing XML.
roXMLList: This object is used to contain a list of roXMLElement instances.
The "." Dot Operator has the following features when used with XML objects:
When used with an roXMLElement instance, the "." Dot Operator returns an roXMLList instance of the child tags that match the dot operand. If no tags match the operand, an empty list is returned.
When applied to an roXMLList instance, the "." Dot Operator aggregates the results of performing the above operation on each roXMLElement in the list.
When applied to XML, which is technically case sensitive, the "." Dot Operator is still case insensitive. If you wish to perform a case-sensitive XML operation, use the member functions of the roXMLElement/roXMLList objects.
The “@” Attribute Operator can be used with an roXMLElement instance to return a named attribute. Though XML is case sensitive, the Attribute Operator is always case insensitive. If the Attribute Operator is used with an roXMLList instance, it will only return a value if that list contains exactly one element.
<?xml version="1.0" encoding="utf-8" ?>
<rsp stat="ok">
<photos page="1" pages="5" perpage="100" total="500">
<photo id="3131875696" owner="21963906@N06" secret="f248c84625" server="3125"
farm="4" title="VNY 16R" ispublic="1" isfriend="0" isfamily="0" />
<photo id="3131137552" owner="8979045@N07" secret="b22cfde7c4" server="3078"
farm="4" title="hoot" ispublic="1" isfriend="0" isfamily="0" />
<photo id="3131040291" owner="27651538@N06" secret="ae25ff3942" server="3286"
farm="4" title="172 • 365 :: Someone once told me..." ispublic="1" isfriend="0"
/>
</photos>
</rsp> |
Given the XML in the above example.xml file, then the following code will return an roXMLList instance with three entries:
rsp=CreateObject("roXMLElement")
rsp.Parse(ReadAsciiFile("example.xml"))
? rsp.photos.photo |
The following will return an roXMLElement reference to the first photo (id="3131875696"):
? rsp.photos.photo[0] |
The following will return an roXMLList reference containing the <photos> tag:
? rsp.photos |
The following will return the string “100”:
rsp.photos@perpage |
You can use the roXMLElement.GetText() method to return an element’s text: For example, if the variable <booklist> contains the element <book lang=eng>The Dawn of Man</book>, then the following code will print the string “The Dawn of Man”.
Print booklist.book.gettext() |
Alternatively, using the Attribute Operator will print the string “eng”.
print booklist.book@lang |
REM
REM Interestingness
REM pass an (optional) page of value 1 - 5 to get 100 photos
REM starting at 0/100/200/300/400
REM
REM returns a list of "Interestingness" photos with 100 entries
REM
Function GetInterestingnessPhotoList(http as Object, page=1 As Integer) As Object
print "page=";page
http.SetUrl("http://api.flickr.com/services/rest/?method=flickr.interestingness.getList&api_key=YOURKEYGOESHERE&page="+mid(stri(page),2))
xml=http.GetToString()
rsp=CreateObject("roXMLElement")
if not rsp.Parse(xml) then stop
return helperPhotoListFromXML(http, rsp.photos.photo) 'rsp.GetBody().Peek().GetBody())
End Function
Function helperPhotoListFromXML(http As Object, xmllist As Object, owner=invalid As dynamic) As Object
photolist=CreateObject("roList")
for each photo in xmllist
photolist.Push(newPhotoFromXML(http, photo, owner))
end for
return photolist
End Function
REM
REM newPhotoFromXML
REM
REM Takes an roXMLElement Object that is an <photo> ... </photo>
REM Returns an brs object of type Photo
REM photo.GetTitle()
REM photo.GetID()
REM photo.GetURL()
REM photo.GetOwner()
REM
Function newPhotoFromXML(http As Object, xml As Object, owner As dynamic) As Object
photo = CreateObject("roAssociativeArray")
photo.http=http
photo.xml=xml
photo.owner=owner
photo.GetTitle=function():return m.xml@title:end function
photo.GetID=function():return m.xml@id:end function
photo.GetOwner=pGetOwner
photo.GetURL=pGetURL
return photo
End Function
Function pGetOwner() As String
if m.owner<>invalid return m.owner
return m.xml@owner
End Function
Function pGetURL() As String
a=m.xml.GetAttributes()
url="http://farm"+a.farm+".static.flickr.com/"+a.server+"/"+a.id+"_"+a.secret+".jpg"
return url
End Function |