Need help translating a Make File into Meson Build File for Vala - gtk

Question

I am working on an Application in Vala. I need to use both webkit2gtk-web-extension-4.0 and webkit2gtk-4.0 in an single project.
I am following the example from -
https://github.com/rschroll/webkitdom/tree/extension
The Make File from the example is as follows:
PKGS=--pkg gtk+-3.0 --pkg libsoup-2.4
EXEC=dom-test
SOURCES=dom-test.vala custom-web-view.vala
LIB_BASE=dom-server
LIB_SOURCES=$(LIB_BASE).vala
LIBRARY=$(LIB_BASE).so
# If you have webkit2gtk-4.0 installed, you will need a Vala from git
# version 6a1a1ab1 (2014/10/16) or later, in order to have the fixed
# .vapi files.
#WEBKIT_VAPI=--pkg webkit2gtk-4.0
#WEBKIT_EXT_VAPI=--pkg webkit2gtk-web-extension-4.0
# Otherwise, use the -3.0 versions included here
WEBKIT_VAPI=--vapidir=. --pkg webkit2gtk-3.0
WEBKIT_EXT_VAPI=--vapidir=. --pkg webkit2gtk-web-extension-3.0 -X -I/usr/include/webkitgtk-3.0
all: $(EXEC) $(LIBRARY)
$(EXEC): $(SOURCES)
valac $(WEBKIT_VAPI) $(PKGS) $^
$(LIBRARY): $(LIB_SOURCES)
valac $(WEBKIT_EXT_VAPI) $(PKGS) --library=$(LIB_BASE) -X -fPIC -X -shared -o $# $^
clean:
rm $(EXEC) $(LIBRARY)
With Meson Build system, I tried to create a subproject with the shared library and link the shared library in the main project. But I am getting the error
DOMServer.vala:1.1-1.10: error: The root namespace already contains a definition for `WebKit'
The main project meson.build file as follows:
project('com.linappfoundry.athmanam', ['c', 'vala'])
domserver_proj = subproject('DOMServer')
domserver_lib = domserver_proj.get_variable('domserver_lib')
cc = meson.get_compiler('c')
m_dep = cc.find_library('m', required : false)
executable(
meson.project_name(),
'AthmanamApp.vala',
'Widgets/MainWindow.vala',
'Widgets/PoemParserWebView.vala',
dependencies: [
dependency('gtk+-3.0'),
dependency('glib-2.0'),
dependency('libsoup-2.4'),
dependency('webkit2gtk-4.0'),
dependency('json-glib-1.0'),
dependency('libxml-2.0'),
m_dep
],
link_with: [domserver_lib],
install: true
)
And subproject's meson.build file is as follows:
project('com.linappfoundry.athmanam.DOMServer', ['c', 'vala'])
domserver_lib = shared_library(
'com.linappfoundry.athmanam.DOMServer',
'src/DOMServer.vala',
dependencies: [
dependency('glib-2.0'),
dependency('gtk+-3.0'),
dependency('libsoup-2.4'),
dependency('webkit2gtk-web-extension-4.0')
],
install: true
)
I am not sure what I am doing wrong here, as I am new to both Vala and Meson.

Answer 1

The error
DOMServer.vala:1.1-1.10: error: The root namespace already contains a definition for `WebKit'
is from the Vala compiler and is saying there is already a definition of Webkit in the global namespace. The error could be as simple as using a keyword with the wrong case, e.g. Using Webkit; when it should be using Webkit;.
Webkit is defined as a namespace in the global (root) namespace and that is done in the VAPI file. Try and find where it is being redefined as something else.