How to make flask app download upon click

Once the file finishes execution, a new file called database. Add it directly after the imports:. Row so you can have name-based access to columns. This means that the database connection will return rows that behave like regular Python dictionaries.

Then you execute an SQL query to select all entries from the posts table. You implement the fetchall method to fetch all the rows of the query result, this will return a list of the posts you inserted into the database in the previous step. You close the database connection using the close method and return the result of rendering the index.

You also pass the posts object as an argument, which contains the results you got from the database, this will allow you to access the blog posts in the index.

Remember that post will be a dictionary-like object, so you can access the post title with post['title']. You also display the post creation date using the same method. Once you are done editing the file, save and close it.

Then navigate to the index page in your browser. You can call it by passing it an ID and receive back the blog post associated with the provided ID, or make Flask respond with a Not Found message if the blog post does not exist.

To respond with a page, you need to import the abort function from the Werkzeug library, which was installed along with Flask, at the top of the file:. You add the fetchone method to get the result and store it in the post variable then close the connection. If the post variable has the value None , meaning no result was found in the database, you use the abort function you imported earlier to respond with a error code and the function will finish execution.

If however, a post was found, you return the value of the post variable. Save the app. Type the following code in this new post. This will be similar to the index. You add the title block that you defined in the base.

You can now navigate to the following URLs to see the two posts you have in your database, along with a page that tells the user that the requested blog post was not found since there is no post with an ID number of 3 so far :.

First, open the index. The links on the index page will now function as expected. Up to this point, you have an application that displays the posts in your database but provides no way of adding a new post unless you directly connect to the SQLite database and add one manually. This secret key is used to secure sessions, which allow Flask to remember information from one request to another, such as moving from the new post page to the index page.

The user can access the information stored in the session, but cannot modify it unless they have the secret key, so you must never allow anyone to access your secret key. See the Flask documentation for sessions for more information.

Add it directly following the app definition before defining the index view function:. Add this new function at the bottom of the file:. GET requests are accepted by default. To create the template, open a file called create. Most of this code is standard HTML. It will display an input box for the post title, a text area for the post content, and a button to submit the form.

For example, if you write a long post and you forget to give it a title, a message will be displayed informing you that the title is required.

This will happen without losing the post you wrote since it will be stored in the request global object that you have access to in your templates. This form submits a POST request to your create view function. However, there is no code to handle a POST request in the function yet, so nothing happens after filling in the form and submitting it. You can separately handle the POST request by checking the value of request.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Flask: Download a csv file on clicking a button [duplicate] Ask Question. Asked 6 years, 6 months ago. Active 2 years, 2 months ago. Viewed 74k times. Tarun Dugar Tarun Dugar 8, 7 7 gold badges 39 39 silver badges 70 70 bronze badges. To do all this we will use Flask. What is Flask?

Flask A Python Microframework It makes the process of designing a web application simpler. How Does a Flask App Work? The code lets us run a basic web application that we can serve, as if it were a website. This is what the app. Go to that address and you should see the following: Congrats! You made a website with Flask! More Fun with Flask Earlier you saw what happened when we ran main. So far we have been returning text. I called mine home. Here is some code to get you started.

Remember to always keep the main. Content of about. Moving Forward with Flask and virtualenv Now that you are familiar with using Flask, you may start using it in your future projects. Why use virtualenv? You may use Python for others projects besides web-development. How the directory looks like Activating the virtual environment Now go to your terminal or command prompt. Now we want to show the whole world our project.

Before you Start: You will need a Google Account. At the end of this tutorial your project structure will look like this. Project Folder Structure We will need to create three new files: app. Content of app. Run this command: pip install -t lib -r requirements. The application will be store in the following way: "your project id". Learned how to create Virtual Environments using virtualenv.

What I learned I learned three important things from this small project. The content of the site does not change when the user interacts with it. In a web application, the server is responsible for querying, retrieving, and updating data.

This causes web applications to be slower and more difficult to deploy than static websites for simple applications Reddit. Server Side and Client Side: I learned that a web application has two sides. The client side and the server side.

Next I will create main. In the above source code, the root path or endpoint will simply render the UI. This UI contains only one link for downloading a file from the server. Clicking on the link will ask user to save the file in a chosen location. The file type could be anything. As you see I have tested with four types of files.

I hope this example will work with other file types as well. Now create a download. Notice in the above template file I am using Flask EL Expression language to evaluate the link endpoint.