Databases
StackOverflow2013
Postsdbo
POHow to pass an associative array from a Node.js C++ addon to js code?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHow to pass an associative array from a Node.js C++ addon to js code?
    primarykey
    data
    text
    <p>So, I want to pass a map from C++ code to js script. Keys are numbers and values are lists with objects that are wrapped using ordinary Node.js techniques. That's the code:</p> <pre><code>Handle&lt;Value&gt; topologicalSortedGraph( const Arguments &amp;args ) { HandleScope scope; ... QMap&lt;int, QList&lt;Actor *&gt; &gt; topologicalSortedGraph = scriptContext-&gt;getTopologicalSortedGraph(); const int schemeTiersCount = topologicalSortedGraph.size(); Local&lt;Object&gt; scheme = Object::New( ); for ( int i = 0; schemeTiersCount &gt; i; ++i ) { Local&lt;Object&gt; tier = Object::New( ); foreach ( Actor *actor, topologicalSortedGraph[i] ) { Handle&lt;Value&gt; actorInitData[] = { Int32::New( reinterpret_cast&lt;int&gt;( actor ) ) }; Handle&lt;Value&gt; wrappedActor = ActorWrap::newInstance( 1, actorInitData ); tier-&gt;Set( String::NewSymbol( actor-&gt;getId( ).toLocal8Bit( ).constData( ) ), wrappedActor ); } scheme-&gt;Set( i, tier ); } return scope.Close( scheme ); } </code></pre> <p>Then I invoke following code in the script:</p> <pre><code>var addon = require('./Addon'); ... var scheme = addon.topologicalSortedGraph(); for (var number in scheme) { for (var actor in scheme[number]) { if (actor.isReady()) { addon.tick(actor); break; } } } ... </code></pre> <p>The issue is the script cannot recognize an 'actor' object and it prints to console 'undefined' when 'actor.isReady()' is being invoked. BTW, here is the definition of 'ActorWrap' class:</p> <pre><code>class ActorWrap : public node::ObjectWrap { public: static void init( ); static Handle&lt;Value&gt; newInstance( int argc, const Handle&lt;Value&gt; *argv ); private: ActorWrap( const Actor *initActor ); ~ActorWrap( ); static Handle&lt;Value&gt; newObject( const Arguments &amp;args ); static Handle&lt;Value&gt; id( const Arguments &amp;args ); static Handle&lt;Value&gt; label( const Arguments &amp;args ); static Handle&lt;Value&gt; isDone( const Arguments &amp;args ); static Handle&lt;Value&gt; isReady( const Arguments &amp;args ); static Persistent&lt;Function&gt; CONSTRUCTOR; static const char * CLASS_NAME; const Actor * actor; }; </code></pre> <p>And implementation:</p> <pre><code>Persistent&lt;Function&gt; ActorWrap::CONSTRUCTOR; const char *ActorWrap::CLASS_NAME = "Actor"; ActorWrap::ActorWrap( const Actor *initActor ) : actor( initActor ) { } ActorWrap::~ActorWrap( ) { } void ActorWrap::init( ) { Local&lt;FunctionTemplate&gt; tpl = FunctionTemplate::New( newObject ); tpl-&gt;SetClassName( String::NewSymbol( CLASS_NAME ) ); tpl-&gt;InstanceTemplate()-&gt;SetInternalFieldCount( 1 ); tpl-&gt;PrototypeTemplate( )-&gt;Set( String::NewSymbol( "id" ), FunctionTemplate::New( id )-&gt;GetFunction( ) ); tpl-&gt;PrototypeTemplate( )-&gt;Set( String::NewSymbol( "label" ), FunctionTemplate::New( label )-&gt;GetFunction( ) ); tpl-&gt;PrototypeTemplate( )-&gt;Set( String::NewSymbol( "isDone" ), FunctionTemplate::New( isDone )-&gt;GetFunction( ) ); tpl-&gt;PrototypeTemplate( )-&gt;Set( String::NewSymbol( "isReady" ), FunctionTemplate::New( isReady )-&gt;GetFunction( ) ); CONSTRUCTOR = Persistent&lt;Function&gt;::New( tpl-&gt;GetFunction( ) ); } Handle&lt;Value&gt; ActorWrap::newInstance( int argc, const Handle&lt;Value&gt; *argv ) { HandleScope scope; Handle&lt;Value&gt; objectInitData[] = { argv[0] }; Local&lt;Object&gt; instance = CONSTRUCTOR-&gt;NewInstance( 1, objectInitData ); return scope.Close( instance ); } Handle&lt;Value&gt; ActorWrap::newObject( const Arguments &amp;args ) { HandleScope scope; const Actor *actor = reinterpret_cast&lt;Actor *&gt;( args[0]-&gt;Int32Value( ) ); Q_ASSERT( NULL != actor ); ActorWrap *obj = new ActorWrap( actor ); obj-&gt;Wrap( args.This( ) ); return args.This( ); } Handle&lt;Value&gt; ActorWrap::id( const Arguments &amp;args ) { HandleScope scope; ActorWrap* obj = ObjectWrap::Unwrap&lt;ActorWrap&gt;( args.This( ) ); return scope.Close( String::New( obj-&gt;actor-&gt;getId( ).toLocal8Bit( ).constData( ) ) ); } Handle&lt;Value&gt; ActorWrap::label( const Arguments &amp;args ) { HandleScope scope; ActorWrap* obj = ObjectWrap::Unwrap&lt;ActorWrap&gt;( args.This( ) ); return scope.Close( String::New( obj-&gt;actor-&gt;getLabel( ).toLocal8Bit( ).constData() ) ); } Handle&lt;Value&gt; ActorWrap::isDone( const Arguments &amp;args ) { HandleScope scope; ActorWrap* obj = ObjectWrap::Unwrap&lt;ActorWrap&gt;( args.This( ) ); LocalWorkflow::BaseWorker *worker = obj-&gt;actor-&gt;castPeer&lt;BaseWorker&gt;( ); Q_ASSERT( NULL != worker ); return scope.Close( Boolean::New( worker-&gt;isDone() ) ); } Handle&lt;Value&gt; ActorWrap::isReady( const Arguments &amp;args ) { HandleScope scope; ActorWrap* obj = ObjectWrap::Unwrap&lt;ActorWrap&gt;( args.This( ) ); LocalWorkflow::BaseWorker *worker = obj-&gt;actor-&gt;castPeer&lt;BaseWorker&gt;( ); Q_ASSERT( NULL != worker ); return scope.Close( Boolean::New( worker-&gt;isReady() ) ); } </code></pre> <p>I suspect that something goes wrong when I initialize a 'tier' object in the first snippet. I didn't managed to find any information about setting an object as a property of another one, so may be I was wrong when called just "obj1->Set( string, obj2 );"</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USIvan
    1. USIvan
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POHow to pass an associative array from a Node.js C++ addon to js code?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POHow to pass an associative array from a Node.js C++ addon to js code?
      1. This table or related slice is empty.
      1. VTUpMod
    1. COIt's hard to say since this is a lot of code, but have you done any debugging to narrow down the source? Is the C++ `isReady` being run, even if the return value is wrong? Can you try to simplify a reproducible case?
      singulars
      1. POHow to pass an associative array from a Node.js C++ addon to js code?
      1. USloganfsmyth
    2. COYes, I have. `isReady()` isn't invoked. Script just outputs `undefined` to console like there is no object or such method. That's why I guess that values of `scheme` array ain't initilized properly in C++ code.
      singulars
      1. POHow to pass an associative array from a Node.js C++ addon to js code?
      1. USIvan
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload