Question

Have the following domain class:

class Topic {
    byte[] image
}

It’s controller:

class TopicController {

def uploadImage () {
        println params
        if(params.image && params.id && params.image.length != 0){
            def topic = Topic.get(params.id)
            topic.image = params.image
        }
    }

}

And ajax request:

function postImage(){
    var topicId = $('#topic-id').attr('value');
    var imageData = context.getImageData(0,0,canvas.width, canvas.height);
    $.post("../uploadImage", {'id': topicId,'image': imageData.data});
}

It’s not enabled to send image data (imageData.data). What’s right way to do it?
When i remove all references to image, that’s okay, but not what i want. In another case neither id nor image are detected on controller’s side (params map).

UPDATE: The problem was solved in such way. Controller method:

def uploadImage() {
    //println params
    if(params.image && params.id){
        def topic = Topic.get(params.id)
        topic.image = Base64.decode(params.image)
    }
}

JS function:

function postImage(){
        var topicId = $('#topic-id').attr('value');
        var image = canvas.toDataURL("image/png");
        image = image.replace('data:image/png;base64,', '');
        $.post("../uploadImage", {'id': topicId,'image': image});
    }

But i continue to get next messages on the browser side:

Failed to load resource: the server responded with a status of 404 (Not Found)
POST ../uploadImage 404 (Not Found)

What should i do to fix it?

Answer 1

To fix your remaining issue, try rendering some content at the end of your uploadImage method:

def uploadImage() {
    //println params
    if(params.image && params.id){
        def topic = Topic.get(params.id)
        topic.image = Base64.decode(params.image)
    }

    render 'Success'
}

If you don’t do something that causes the response to be committed (e.g. render() or redirect()), Grails will try to render a view with the same name as the action (in your case, uploadImage.gsp).