MapKnitter is a map making open source tool. It is a unique tool which helps to knit a map using a very simple smooth process with amazing user experience. The user just enters the title of the map, the place or the coordinates of the place. After the map is created, the user can upload images and plot them, resize them and perform other functions with the image.

Recently I worked on the task of Multiple images export. It is a very good function of MapKnitter that helps the user get all the images in jpg, zip, and GeoTIFF format.

Previously, the image exporter of map knitter was as follows:
All the images of the map were exported and then the user would download the entire zip which contains the Knitted images.
Now, the user can select only the images he would like to export and just download them.

Now after some modifications which we've done, our functionality is improved as follows.
If in a map, there are a lot of images, and the user wishes to export only a few of them, he can easily to that and the time to export also reduces.

So for this, along with the guidance of my mentor, I implemented multiple image export.

The export function for all the images of the map was already present so I had to just modify it.

First, I created a user interface that shows all the images placed on the grid and the user can select any of the images he would like to export. After selecting an image, a red border was created around it to show that the image is selected and upon deselecting it, it comes to its original state. I did this with the help of jQuery.

After completing this, when the export button is pressed, the Ajax call associated with it records the id of the map and all the images ready for the export. I stored all the images that have a red border just after the Start Export button was clicked. So by this, I was sending an array and retrieving the values in the export function of maps controller.

The complete activity can be seen in this PR.

I would also be writing a blog on image reordering in the sidebar using drag and drop and by sorting using different parameters.