S3 File Manager

1. Setting up the S3 bucket:

   First and foremost we need to setup the S3 bucket as a datasource in Appsmith. Refer this tutorial to know how to setup the S3 bucket in appsmith

2. Setting up the UI:

   Next we can continue with building the UI of the App.

   Step 1 : Header

   • Drag and drop a container, which will act as a container for the header

     
   • Next add a Text widget and change the text to "S3 File Manager"

   • Then add an icon button to add the icon of a folder. 

     

    

   Step 2: Bucket Selection

   • Next add a input widget into the canvas, this will act as an input to select the bucket we need to access. Here I am naming the widget as inp_bucket.

     Note:  It is important to name the widgets meaningfully, as it helps us to organise the code and it is easy to bind the widget to the JS Object or Query.

     
   • Then again add a icon widget to refresh the files list
   • Then add a button to open the upload modal
   • Finally add the image widget to show the S3 logo
   • 

    

   Step 3: Main Body

   • Now let's begin building the Main body
   • Drag a list widget into the canvas
   • And remove one of the text widget in the elements and add an icon button.
   • Then add an Tab Widget into the canvas to preview the different files
   • And add the following as the Tab:
     • Image
     • Video
     • Doc

     • Audio

        

   • 

    

   Step 4 : Preview Tab

   • Let's edit the Tab widget we have added in the previous step

   • Now add an Image widget in the image tab

     

   • In the same way add the Video widget into the Video tab

     

   • Next do the same for Doc tab by adding the document viewer widget

     

   • Finally let's finish this step by adding the Audio Widget to the Audio tab

     

   Step 4: Upload Modal

   • Now drag and drop a modal into the canvas.

   • Next change the modal title to Upload to Bucket : {{inp_bucket}}

     

   • Next add a FilePicker Widget, rename it to fpk_upload. This name will be used while writing the JS Code for the Upload logic and change the text to upload File

     
   • Next add an icon button to reset the modal . 

   • Then set the onClick function to reset the mdl_upload modal

     
   • Then add the input widget, Also rename this to inp_FileName, to input the name of the file

   • Set the default value to {{fpk_upload.files[0]?.name || ''}}

     
     

3. Configuring the Queries:

   What is a Query?

   A query is a request for information or action sent to a database, application, or API. It typically retrieves specific data or performs operations based on predefined parameters, helping users extract relevant information or manipulate data according to their needs.

   We need to create 3 queries for this application

   1. getFiles
   2. insertFiles
   3. deleteFiles

   First, Let's create the getFiles query

   getFiles Query:

   This query is required to get all the files in the bucket

   • Go to Queries Tab in appsmith, then click on new Query and select your S3 Datasource

     
   • Next change the bucket name to {{inp_bucket.text}}

   • change the signedURL to yes and unsignedURL to no

     

    

   insertFiles Query:

   This query is used to insert a new file into the bucket. 

   • Again go to the queries tab and click on new Query
   • Change the command to Create a new file .
   • Change the bucket name to {{inp_bucket.text}}

   • And the content to {{fpk_upload.files[0]}} 

     

    

   deleteFiles Query:

   This query is used to delete the files in the bucket

   • Again create a new query.
   • Change the command to Delete Files
   • Change the bucket name to {{inp_bucket.text}}

   • Change the filePath to {{lst_files.selectedItem?.fileName}}

     Note: The chaining operator (?.) in JavaScript allows safe access to properties of an object without causing errors if intermediate properties are undefined or null. It short-circuits evaluation and returns undefined if any part of the chain is null or undefined. For further details, Refer this

     

      

    

4. Writing JS Codes:

    

   Why we need JS in appsmith?

   JavaScript in Appsmith enables dynamic user interfaces, seamless API integration, custom logic implementation, event handling, and data manipulation. It's essential for creating interactive and functional applications that meet specific requirements and provide a superior user experience.

    

   Now let's create a new JS file in appsmith.

   Go to JS -> + New JS Object

   Here, I am giving the name JSUtils For this JS Object.

   First we need to custom logic to decide which tab needs to be shows for that specific file format. 

   defaultTab: {
           html: 'Doc',
           txt: 'Doc',
           gif: 'Image',
           jpg: 'Image',
           jpeg: 'Image',
           png: 'Image',
           svg: 'Image',
           mp4: 'Video',
           mkv: 'Video',
           mpeg: 'Video',
           doc: 'Doc',
           docx: 'Doc',
           pdf: 'Doc',
           mp3: 'Audio',
           wav: 'Audio'
       },
       nameToExt(name=lst_files.selectedItem?.fileName){
           if(!name){return 'Image'}
           const ext = name?.split('.').pop().toLocaleLowerCase();
           return this.defaultTab[ext]
       }

   This code splits the extension of the file from the file name and finds the appropriate tab to showcase/preview the file.

   This object named defaultTab contains key-value pairs where the keys represent file extensions (without the dot) and the values represent the default category associated with those file types. For example, HTML, TXT, and DOC files are categorised as "Doc", while GIF, JPG, PNG, and SVG files are categorised as "Image". Similarly, MP4, MKV, and MPEG files are categorised as "Video", and MP3 and WAV files are categorised as "Audio".

   The function extracts the file extension by splitting the name at the last dot and converting it to lowercase. This is done to ensure consistency as file extensions are often case-insensitive.

   Then, the function looks up the file extension in the defaultTab object defined earlier. If a matching category is found, it returns that category; otherwise, it returns 'Image' by default.
    

   Next we have the upload logic

   uploadFile: async () => {
           await insertFiles.run();
           await closeModal('mdl_upload');
           resetWidget('fpk_upload')
           await getFiles.run()
       }

   And then we have the Default item Logic for the list

   defaultItem: 0

   The entire code for the JS is Here:

   export default {
       
       defaultItem: 0,
       
       uploadFile: async () => {
           await insertFiles.run();
           await closeModal('mdl_upload');
           resetWidget('fpk_upload')
           await getFiles.run()
       },
       
       defaultTab: {
           html: 'Doc',
           txt: 'Doc',
           gif: 'Image',
           jpg: 'Image',
           jpeg: 'Image',
           png: 'Image',
           svg: 'Image',
           mp4: 'Video',
           mkv: 'Video',
           mpeg: 'Video',
           doc: 'Doc',
           docx: 'Doc',
           pdf: 'Doc',
           mp3: 'Audio',
           wav: 'Audio'
       },
       nameToExt(name=lst_files.selectedItem?.fileName){
           if(!name){return 'Image'}
           const ext = name?.split('.').pop().toLocaleLowerCase();
           return this.defaultTab[ext]
       }
   
   }

5. Connecting Queries & JS Object with Widgets:

   Now let's connect the widgets with the queries.

   First Let's connect the list Widget with the getFiles Query.

   • Select the list widget and in the properties tab
   • Set the items to {{getFiles.data}}
   • And set the Data Identifier to fileName
   

   Next set the defaultItem of the list widget to {{JSUtils.defaultItem}}

   Then we need to connect the list elements, 

   First select the Image widget in the list. and change its Data to {{currentItem.signedUrl}}

   

   Next select the text widget inside the list and change its Text to {{currentItem.fileName}}

   

   And set the onClick property of the icon button with the delete symbol to deleteFiles Query

   

   Now let's connect the defaultTab property of the tab widget to {{JSUtils.nameToExt() || 'Image'}}

   

   Next let's connect each of the preview tabs(Image, Video, Doc, Audio)

   Select the Image Widget and set the Data to {{lst_files.selectedItem?.signedUrl}}

   

   Similarly do this for the video, Doc and audio widget using the same code
    

   
   
   

   
    Next let's connect the upload button with the JS Code

   • Select the Modal and Select the Upload button. 
   • in the properties panel, Set the onClick property to Execute a JS Function -> JSUtils -> uploadFile
   

   That's all, Now we have a working S3 File Manager app entirely made using appsmith

Conclusion

Additional Resources

• App Preview