QML script provider similar to image provider

harchu

Hi, I have written a simple image provider which basically gets the images from the network. Is there something similar that can be done for javascript files as well? I want to be able to get the javascript resources from the network too using my custom code. Where would i have to make the change to do this?
Thanks,
Rohit

p3c0

Hi,

To load an Image from Network in QML you can use
@
Image {
source: "http://upload.wikimedia.org/wikipedia/commons/b/b8/Qt-logo.png"
}
@

And use import to get JavaScript from network. for eg.
@
import "http://192.168.0.16/sample.js" as Remote

Component.onCompleted: console.log(Remote.myFunction())
@

Remember that the Qualifier should start with a Capital letter.

harchu

Hi,
Thanks for the reply.
I needed to use custom code to get these javascript files. For example, for the images, i was able to do that using a custom Image provider where I can add some security and get the image id and i can get the image from my resource manager. I want to be able to do the same for scripts which i will obtain from the same resource manager. Is there a way to achieve that?
Thanks,
Rohit

p3c0

Do you mean you want to download JavaScript files from C++ code ?

harchu

Yes, that is right. I want to be able to download the file from c++ and then use it. I am assuming i would have to make a change to or inherit from some Qt class.
Basically i want to have control over obtaining the javascript file, since i want to add a security layer. if there is a solution to do this from javascript, then that would work too.
Thanks,
Rohit

p3c0

You can use "QNetworkAccessManager::get":http://qt-project.org/doc/qt-5/qnetworkaccessmanager.html#get to download the file. Checkout the examples for how to use it.

harchu

Ok. but how do i make Qt/QML use this code to download the file? Can it be done via a plugin?
I want to be able to use this custom code when someone writes:
import "some-uri" as Remote
At this point it should get the file using my plugin.

p3c0

bq. but how do i make Qt/QML use this code to download the file?

From C++ did you check the examples of QNetworkAccessManager::get ?

You can call C++ functions from QML. Check "qtqml-cppintegration-topic":http://qt-project.org/doc/qt-5/qtqml-cppintegration-topic.html and especially "qtqml-cppintegration-exposecppattributes":http://qt-project.org/doc/qt-5/qtqml-cppintegration-exposecppattributes.html
I'm not sure about the plugin as I have never used one.

harchu

@p3c0: Thanks. I get how to use the QNetworkAccessManager to download the file. But I need to be able to run this code whenever someone uses the import statement for external javascript files. Sorry for not being clear before.

p3c0

Well then check "registering-an-instantiable-object-type":http://qt-project.org/doc/qt-5/qtqml-cppintegration-definetypes.html#registering-an-instantiable-object-type. Create a Q_INVOKABLE function in it where you download the file then you can call this function from QML after instantiating it.

harchu

@p3c0: I am not able to get the example you stated above to work actually

import "http://192.168.0.16/sample.js" as Remote

I have my own node.js file server running on 8030 which i am trying to access using the below import statement:

import "http://127.0.0.1:8030/testbrowser.js" as Browser

Sometimes it does send a request to my server and my server correctly responds too, but the app then exits for some reason. do you know why that is?

thanks,
Rohit

p3c0

Sorry but i haven't used node.js. I have used it with particularly simple example like few JavaScript functions in sample.js and it works as expected.

harchu

Actually node.js is not the issue here..as the server does work when i try to access the file in the browser.
Do you know why the download would not work in QML? My app exits with an exit code 255.
Thanks

p3c0

Can you try with some simple Javascript file which will contain just a few functions ?

harchu

i tried with an empty javascript file too and it did not seem to work

p3c0

I tested it with apache server and it worked. The js file contains a simple function which returns a string.

sample.js
@
function myFunction() {
return "Hello Qt"
}
@

and the from QML
@
import "http://192.168.1.3/sample.js" as Remote
...
//and on some Button click calling it as
Remote.myFunction()
@

harchu

It seems to work when I create a Qt Quick Application project from Qt Creator and try to import the javascript file from the node js server.

However the import fails when I create a Qt Quick UI project. Is there a way to enable this behavior in a Qt Quick UI project?