.. _custom_images:

------

Uploading custom display images, file-system support
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. note::
    This feature is available from Visionect Software Suite 3.2 onward.

**Uploading custom images**

Uploading an image file to the Visionect client device. The function takes a base64 encoded PNG image and uploads it to the electronic paper sign. The server transforms the PNG image to the device image format before uploading it.

.. code-block:: javascript

    okular.SetImage(target, name, imageData)


Parameters:
 - Target device UUID string.
 - The name parameter should be set to "disconnected", as only changing the disconnected image is currently supported.
 - An imageData base64 encoded PNG image in the data URL string format

Returns: Promise, which is resolved ether with ‘Error’ or with the device file checksum string.

Example:

.. code-block:: javascript

    okular.SetImage(okular.device_uuid, "disconnected", "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQAQMAAAAlPW0iAAAABlBMVEUAAAD///+l2Z/dAAAAM0lEQVR4nGP4/5/h/1+G/58ZDrAz3D/McH8yw83NDDeNGe4Ug9C9zwz3gVLMDA/A6P9/AFGGFyjOXZtQAAAAAElFTkSuQmCC").then(function(result) {
          console.log(result); // Success: print uploaded checksum
      }, function(err) {
          console.log(err);
          // Error: Maybe retry later.
      });




**Displaying a list of files on device**

The API allows the user to list the files located on the device:

.. code-block:: javascript

    okular.ListFiles(target)


Parameters:
 - Target device UUID string.

Returns: Promise, which is resolved ether with ‘Error’ or with the object, containing a file list in the following format:

.. code-block:: javascript

    {"filename1":{"checksum":  string, "size": string }, "filename2":{"checksum":  "...", size: "..." }, ... }


Example:

.. code-block:: javascript

    okular.ListFiles(target).then(function(result) {
          console.log(result); // Success: stuff worked!
    }, function(err) {
          console.log(err);
          // Error: Maybe retry later.
    });
    // Output: {"disconnected.pv2":{"checksum":"1960206407","size":"74975"}}