Roku Developer Program

[cesarcarlos]

I'm new to Roku deveopment and I'm trying to set up a posterGrid on my Home Screen:

HomeScreen.xml

<?xml version="1.0" encoding="UTF-8"?>
<component name="HomeScreen" extends="Group" initialFocus="topics">
    <script type="text/brightscript" uri="HomeScreen.brs" />
    
    <interface>
        <field id="content" type="node" onChange="loadTopics" alwaysNotify="true" />
    </interface>

    <children>
        <PosterGrid 
            id="topics"
            translation="[20,100]"
            basePosterSize="[304,182]"
            itemSpacing = "[10,20]"
            posterDisplayMode = "scaleToFill"
            numColumns = "4"
        />
    </children>
</component>

 I call the RunContentTask sub from MainScene.brs

sub RunContentTask()
    ' Create task for feed retrieving
    m.contentTask = CreateObject("roSGNode", "HomeLoaderTask")
    ' Observe content so we can know when feed content will be parsed
    m.contentTask.ObserveField("content", "OnMainContentLoaded")
    ' GetContent method is executed (MainLoaderTask.brs)
    m.contentTask.control = "run"
    ' Show loading indicator while content is loading
    m.loadingIndicator.visible = true
end sub

sub OnMainContentLoaded()
    ' invoked when content is ready to be used

    ' set focus to home screen
    m.HomeScreen.SetFocus(true)

    ' hide loading indicator because content was retrieved
    m.loadingIndicator.visible = false

    ' populate HomeScreen with content
    m.HomeScreen.content = m.contentTask.content
    
end sub

HomeLoaderTask.xml

<?xml version="1.0" encoding="UTF-8"?>
<component name="HomeLoaderTask" extends="Task">
    <interface>
        <field id="content" type="node" />
    </interface>

    <script type="text/brightscript" uri="HomeLoaderTask.brs" />
</component>

HomeLoaderTask.brs

sub Init()
    m.top.functionName = "GetContent"
end sub


sub GetContent()
    ' request the content feed from API
    xfer = CreateObject("roURLTransfer")
    xfer.SetCertificatesFile("common:/certs/ca-bundle.crt")
    xfer.SetURL("https://my/api/topics")
    rsp = xfer.GetToString()
    rootChildren = []
    rows = {}

    json = ParseJson(rsp)
    
    if json <> invalid
        for each category in json
            value = json.Lookup(category)

            ' if parsed key value having other objects in it
            if Type(value) = "roArray"
                row = {}
                row.title = category
                row.children = []
                for each item in value
                    itemData = GetItemData(item)
                    row.children.Push(itemData)
                end for
                rootChildren.Push(row)
            end if
        end for

        contentNode = CreateObject("roSGNode", "ContentNode")
        contentNode.Update({
            children: rootChildren
        }, true)

        m.top.content = contentNode
        
    end if
end sub

function GetItemData(topic as Object) as object
    item = {}
    item.id = topic.topicId
    item.hdPosterURL = topic.url
    item.title = topic.topicName
    return item
end function

Finally in HomeScreen.brs I have the loadTopics() sub

sub Init()
    m.topicsList = m.top.FindNode("topics")
    m.topicsContent = createObject("roSGNode","ContentNode")
    m.top.SetFocus(true)
    m.top.ObserveField("visible", "OnVisibleChange")
end sub

sub OnVisibleChange()
    if m.top.visible = true
        m.topicsList.SetFocus(true)
    end if
end sub

sub loadTopics() ' invoked when item metadata retrieved
    

    content = m.top.content
    
    'there is no data in m.top.content
    ...
end sub

The problem is that even though rootChildren is being populated correctly in HomeLoaderTask.brs, m.top.content isn't (if I try to debug, the contentNode is never populated) so when I try to load the content in the loadTopics() sub, I have no data.

I've been testing this for hours, and have no idea why the data is not being saved to the HomeScreen content field.

[joetesta · Accepted solution]

how are you concluding there's no data; did you check for a child node of the content node?

You're currently setting an array ('rootChildren') of associative arrays as the child of the contentnode, that probably won't work (I believe it expects children to be nodes and not objects like arrays).

If you just want to pass back data, use a field type of "array" or "assocArray" (instead of "node");

in your task xml:

<field id="content" type="array" />

then in your task brs:

m.top.content = rootChildren

[cesarcarlos]

Thanks, this worked!