Load images from disk cache with Picasso if offline

Question

I have some images that I download from different web sites when the app starts, by doing this:

Picasso.with(context).load(image_url).fetch();

Now, suppose the user closes the app and turns offline. When the app starts again, Picasso display the images in this way:

Picasso.with(ctx).load(image_url).placeholder(R.drawable.ph).into(imageView);

The problem is that some images are loaded from the disk cache (yellow triangle in debug mode), and for the others Picasso shows the placeholder.

Why? I'm expecting that every image is loaded from the disk cache.

Bimanous

Perhaps the fetch() has not completed yet and the result is not stored. – Chop

Answer 1

You can use this code by this strategy Picasso will look for images in cache and if it failed only then image will be downloaded over network.

 Picasso.with(context)
                    .load(Uri.parse(getItem(position).getStoryBigThumbUrl()))
                    .networkPolicy(NetworkPolicy.OFFLINE)
                    .into(holder.storyBigThumb, new Callback() {
                        @Override
                        public void onSuccess() {

                        }

                        @Override
                        public void onError() {
                            // Try again online if cache failed
                            Picasso.with(context)
                                    .load(Uri.parse(getItem(position)
                                            .getStoryBigThumbUrl()))
                            .placeholder(R.drawable.user_placeholder)
                            .error(R.drawable.user_placeholder_error)
                                    .into(holder.storyBigThumb);
                        }
                    });

Despoliation

Perfect solution for someone who wants an image caching library! :) – Threescore

No need to write this much :) You can specify multiple network policies. For example .networkPolicy(NetworkPolicy.OFFLINE, NetworkPolicy.NO_CACHE) should have a similar behaviour to your code – Zestful

Answer 2

Do this:

Picasso.with(this)
            .load(url)
            .networkPolicy(NetworkPolicy.OFFLINE)
            .into(imageView);

Also check my previous answer, maybe will help you: Invalidate cache in Picasso

Chigetai

As stated on the API specification, the OFFLINE policy will force the load from disk, skipping network square.github.io/picasso/2.x/picasso/com/squareup/picasso/…. So, if the image changes on server and I am online, will I never notice the change? – Advantage

Answer 3

This logic worked for me:

if network is available:
    Picasso.with(context).load(image).into(imageView);
else:
    Picasso.with(context).load(image).networkPolicy(NetworkPolicy.OFFLINE).into(imageView);

Evangelistic

At least for retrofit:2.2.0, the networkPolicy goes after the load method. – Perreira

Answer 4

Is OkHttp and Okio present on the class path? (or in your dependencies) Because by default Picasso lets the HttpClient handle the caching (it does not do this by default)

You have 2 options

• include the mentioned dependencies (recommended)
• specify the cache manually

Palmetto

it tooks me 3 bloody days to realize that im not inculding those 2 dependencies with picasso , that was really stupid X( X( thank you for pointing that out :D – Brittain

Answer 5

To avoid creating of separate instance of RequestCreator like here , do this:

 RequestCreator request = mPicasso.load(TextUtils.isEmpty(imageUrl) ? null : imageUrl)
                    .placeholder(R.drawable.ic_default)
                    .error(R.drawable.ic_default)
                    .transform(transformations)
                    .noFade()
                    .centerCrop();
            request
                    .networkPolicy(NetworkPolicy.OFFLINE)
                    .into(mImageView, new Callback.EmptyCallback(){
                        @Override
                        public void onError() {
                            super.onError();
                            request.into(mImageView);
                        }
                    });

Lepidote