dash-tools 1.5.1

Plotly Dash Templating and Deployment Tools

Create, Run and Deploy Templated Plotly Dash Apps from Terminal

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About

dashtools is an open-source toolchain for Plotly Dash. With a user-friendly command line interface, creating Dash applications and deploying them to Heroku has never been quicker.

Includes user and developer-friendly app templates where generating a new app only takes seconds. In fact, it will take longer to install this tool than it will to use it.

Installation

Ready to use dashtools? Installation is easy with pip:

pip install dash-tools

Find dash-tools on PyPi

Requires:

• Git CLI which can be downloaded Here
• Heroku CLI which can be downloaded Here
• OS Linux, MacOS, Windows
• Python Version ≥ 3.6

Usage Examples

A. Create an App

1. Create a Dash project in a new directory called "MyDashApp" (using your terminal or command prompt):

   Note

   "MyDashApp" can be changed to any name. However, for the purpose of this tutorial, we recommend keeping it as "MyDashApp".

   dashtools init MyDashApp
   

2. Open the default app.py file that comes with this project:

   Windows

    .\MyDashApp\src\app.py
   

   Linux and Mac OS

    ./MyDashApp/src/app.py
   

3. Replace the code in app.py with your own app code. Make sure to keep the server = app.server right after app instantiation:

4. Make sure you are in your project's root directory:

   cd MyDashApp
   

5. Run your app to ensure it works:

   Linux and Mac OS

   python src/app.py
   

   Windows

   python src\app.py
   

Deploy App to Web with Heroku

6. Deploy to Heroku:

   dashtools heroku --deploy
   

   Alert!

   After the `requirements.txt` file is created, compare the libraries your app is using with the libraries in the `requirements.txt` file. If your app uses additional libraries, make sure to add them to the requirements file before moving forward with the subsequent steps of deployment.

Pushing App Changes to Heroku (Optional)

7. If you make changes to your app after deploying it, push them to Heroku using:

   dashtools heroku --update
   

B. Create an App with Local CSV sheet

A common use for Dash is to display CSV data that is located inside the project folder. For this, you can use the CSV DashTools template to create a project with CSV data.

1. Using App template with CSV

   dashtools init MyCSVApp csv
   

2. Replace the code in app.py with your own app's code, like shown in example A above. Make sure to keep code lines 13, 26, and 27.

   • 13: server = app.server
   • 23: PATH = pathlib.Path(__file__).parent
   • 24: DATA_PATH = PATH.joinpath("data").resolve()

3. Replace the default CSV file in the data folder with your own CSV file

4. Make sure you are in your project's root directory:

   cd MyCSVApp
   

5. Run your app to ensure it works:

   Linux and Mac OS

   python src/app.py
   

   Windows

   python src\app.py
   

Deploy App to Web with Heroku

6. Deploy to Heroku:

   dashtools heroku --deploy
   

   Alert!

   After the `requirements.txt` file is created, compare the libraries your app is using with the libraries in the `requirements.txt` file. If your app uses additional libraries, make sure to add them to the requirements file before moving forward with the subsequent steps of deployment.

Pushing App Changes to Heroku (Optional)

7. If you make changes to your app after deploying it, push them to Heroku using:

   dashtools heroku --update
   

C. Additional Examples

Tutorial - Making Changes and Deploying to Heroku

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Templates

Templates contain boilerplate code for projects, making it much easier to start with useful baseline apps. Example A shown above uses the "default" template, as no template argument was specified. Example B shown above uses the "csv" template.

Available Templates

1. To list out available templates, use the templates --list command:

   dashtools templates --list
   

   Click the dropdowns below to see screenshots.

   Template: 'advanced'

   To use this template, type: dashtools init MyFuturisticApp advanced

   Advanced multi-page template. Includes examples of ClientsideCallbacks, multi-page routing, external stylesheets, header, footer, and 404 page.

   Template: 'csv'

   To use this template, type: dashtools init MyCSVLoaderApp csv

   Example of CSV file loading. Includes the default CSV load example from Plotly.

   Template: 'default'

   To use this template, type: dashtools init MyAmazingApp default

   Basic Dash template. See Dash Docs

   Template: 'fastdash'

   To use this template, type: dashtools init StellarDashApp fastdash

   Fast Dash template. See Fast Dash Docs

   Template: 'iris'

   To use this template, type: dashtools init MyFantasticApp iris

   Iris theme. See Faculty.ai Example

   Template: 'leaflet'

   To use this template, type: dashtools init BestMapApp leaflet

   Dash leaflet plugin. See Dash Leaflet

   Template: 'mantine'

   To use this template, type: dashtools init MyGreatApp mantine

   Basic mantine template. See Dash Mantine

   Template: 'multipage'

   To use this template, type: dashtools init MyPristineApp multipage

   New multipage theme. See Multipage Plugin

   Template: 'sidebar'

   To use this template, type: dashtools init MySnazzyApp sidebar

   Sidebar theme. See Faculty.ai Example

   Template: 'tabs'

   To use this template, type: dashtools init MyBeautifulApp tabs

   Tabs theme with dynamically generated content. See Faculty.ai Example

2. To use a certain template, simply choose a directory name, followed by one of the template names listed above. Here, we will choose "tabs":

   dashtools init MyWonderfulApp tabs
   

3. Follow the steps in Example A to replace default app with your own app and deploy to heroku.

Format

Templates may include different components, modules and layouts. They have the following format:

AppName
│-- Procfile
│-- README.md
│-- requirements.txt [1]
│-- runtime.txt
│
└── src
    |-- app.py
    |-- __init__.py
    |-- assets/      [2]
    |-- containers/  [2]
    |-- components/  [2]
    └-- data/        [2]

[1] Created during deployment

[2] Not included in all templates

Commands

Usage

dashtools <command> [options]

Commands and Options

• heroku Handle Heroku deployment. Choose option:
  • --deploy Deploys the current project to Heroku
  • --update [remote name (OPTIONAL)] Push changes to existing Heroku remote
• init <app name> [template (OPTIONAL)] Create a new app
  • --dir, -d Specify alternative create location
• run Run app locally from the current directory
  • --set-python-shell-cmd Specify the python shell command, e.g. python3 or python3.exe, etc.
• templates List and create templates
  • --init <directory to convert> Creates a template from specified directory
  • --list List available templates

Other Options

• --help, -h Display help message
• --version, -v Display version

Troubleshooting

Running into issues? Outlined below are common errors and solutions. If you do not find an answer below, please Submit an Issue Ticket.

Common heroku --deploy Issues

    Error when creating requirements.txt file

Problem: You encounter an error when generating a requirements.txt file

Solution: Verify that you are running the dashtools heroku --deploy command from a valid plotly dash app directory. E.g. there is a src/app.py file.

    No webpage displayed after Heroku deployment, no error messages

Problem: You are able to deploy your project online to Heroku, but nothing is displayed on the page

Solution1: This may be due to missing libraries that your app needs to run successfully. Check the requirements.txt. file.

Solution2: This may due to the fact that you forgot to add server = app.server to you main app.py file

    Procfile is incorrect

Problem: When deploying, you get an error "Procfile is incorrect"

Solution: When deploying an app, the Procfile is checked for validity. Make sure that your Procfile points to the correct server entrypoint, e.g. server = app.server.

    No solution found

Solution: Try typing into the terminal or command prompt heroku logs --tail. This will give you access to the official heroku logs of your app that enable monitoring your stack error troubleshooting

Common heroku --update Issues

    Your account has reached its concurrent build limit.

Problem: When you try to update and redeploy your app to Heroku too many times within 10 minutes, you will get the above error message

Solution: First, wait a few minutes and try again. If that doesn't work, check out a few possible solutions in this thread.

    Unable to update heroku app

Problem: When you try to update your app, you get an error "Unable to update heroku app. Is the project already deployed?"

Solution: Make sure you have already run git init in the project root directory, and that you have already followed steps to deploy your project to heroku with dashtools heroku --deploy

If both of these steps do not work, verify that the heroku remote was added by running git remote. If you do not see it, try re-deploying your app or manually push to the correct remote with the dashtools heroku --update <remote> option, where <remote> is replaced with the correct remote.

Common init Issues

    No write permission

Problem: You receive a 'write permission' error while trying to init a new app

Solution: Please check your write permissions for the current directory. Try the init command from a different directory.

Common run Issues

    No valid python command found for your system

Problem: You encounter an error: No valid python command found for your system when trying to run your app

Solution: Set the python shell command with "dashtools run --set-python-shell-cmd ". The correct command will be the python command that runs python, eg. python, python.exe, python3, python3.exe on your system. Note that although you may be able to run 'python' from your terminal, this may be an alias command for your terminal, and not the correct command.

    No such file or directory

Problem: You encounter an error: 'No such file or directory' when trying to dashtools run your app

Solution: Verify that you are running the dashtools run command from within a valid project root directory. Your app must be named app.py, or have a valid Procfile pointing to the app file.

    Invalid Procfile

Problem: When you try to run, you get an error "Invalid Procfile"

Solution: When you run an app, the Procfile is checked for validity. Make sure that your Procfile points to the correct server entrypoint, e.g. server = app.server.

Development

See the Developer Guide for more details.

License

MIT License. See LICENSE.txt file.