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#include "mapnik_featureset.hpp"
#include "mapnik_feature.hpp"
Nan::Persistent<v8::FunctionTemplate> Featureset::constructor;
/**
* **`mapnik.Featureset`**
*
* An iterator of {@link mapnik.Feature} objects.
*
* @class Featureset
*/
void Featureset::Initialize(v8::Local<v8::Object> target) {
Nan::HandleScope scope;
v8::Local<v8::FunctionTemplate> lcons = Nan::New<v8::FunctionTemplate>(Featureset::New);
lcons->InstanceTemplate()->SetInternalFieldCount(1);
lcons->SetClassName(Nan::New("Featureset").ToLocalChecked());
Nan::SetPrototypeMethod(lcons, "next", next);
target->Set(Nan::New("Featureset").ToLocalChecked(), lcons->GetFunction());
constructor.Reset(lcons);
}
Featureset::Featureset() :
Nan::ObjectWrap(),
this_() {}
Featureset::~Featureset()
{
}
NAN_METHOD(Featureset::New)
{
if (!info.IsConstructCall())
{
Nan::ThrowError("Cannot call constructor as function, you need to use 'new' keyword");
return;
}
if (info[0]->IsExternal())
{
v8::Local<v8::External> ext = info[0].As<v8::External>();
void* ptr = ext->Value();
Featureset* fs = static_cast<Featureset*>(ptr);
fs->Wrap(info.This());
info.GetReturnValue().Set(info.This());
return;
}
Nan::ThrowTypeError("Sorry a Featureset cannot currently be created, only accessed via an existing datasource");
return;
}
/**
* Return the next Feature in this featureset if it exists, or `null` if it
* does not.
*
* @name next
* @instance
* @memberof Featureset
* @returns {mapnik.Feature|null} next feature
*/
NAN_METHOD(Featureset::next)
{
Featureset* fs = Nan::ObjectWrap::Unwrap<Featureset>(info.Holder());
if (fs->this_) {
mapnik::feature_ptr fp;
try
{
fp = fs->this_->next();
}
catch (std::exception const& ex)
{
// It is not immediately obvious how this could cause an exception, a check of featureset plugin
// implementations resulted in no obvious way that an exception could be raised. Therefore, it
// is not obvious currently what could raise this exception. However, since a plugin could possibly
// be developed outside of mapnik core plugins that could raise here we are probably best still
// wrapping this in a try catch.
/* LCOV_EXCL_START */
Nan::ThrowError(ex.what());
return;
/* LCOV_EXCL_STOP */
}
if (fp) {
info.GetReturnValue().Set(Feature::NewInstance(fp));
}
}
return;
}
v8::Local<v8::Value> Featureset::NewInstance(mapnik::featureset_ptr fsp)
{
Nan::EscapableHandleScope scope;
Featureset* fs = new Featureset();
fs->this_ = fsp;
v8::Local<v8::Value> ext = Nan::New<v8::External>(fs);
Nan::MaybeLocal<v8::Object> maybe_local = Nan::NewInstance(Nan::New(constructor)->GetFunction(), 1, &ext);
if (maybe_local.IsEmpty()) Nan::ThrowError("Could not create new Featureset instance");
return scope.Escape(maybe_local.ToLocalChecked());
}