id,page,ref,title,content,breadcrumbs,references contributing:contributing-upgrading-codemirror,contributing,contributing-upgrading-codemirror,Upgrading CodeMirror,"Datasette bundles CodeMirror for the SQL editing interface, e.g. on this page . Here are the steps for upgrading to a new version of CodeMirror: Install the packages with: npm i codemirror @codemirror/lang-sql Build the bundle using the version number from package.json with: node_modules/.bin/rollup datasette/static/cm-editor-6.0.1.js \ -f iife \ -n cm \ -o datasette/static/cm-editor-6.0.1.bundle.js \ -p @rollup/plugin-node-resolve \ -p @rollup/plugin-terser Update the version reference in the codemirror.html template.","[""Contributing""]","[{""href"": ""https://codemirror.net/"", ""label"": ""CodeMirror""}, {""href"": ""https://latest.datasette.io/fixtures"", ""label"": ""this page""}]" contributing:contributing-using-fixtures,contributing,contributing-using-fixtures,Using fixtures,"To run Datasette itself, type datasette . You're going to need at least one SQLite database. A quick way to get started is to use the fixtures database that Datasette uses for its own tests. You can create a copy of that database by running this command: python tests/fixtures.py fixtures.db Now you can run Datasette against the new fixtures database like so: datasette fixtures.db This will start a server at http://127.0.0.1:8001/ . Any changes you make in the datasette/templates or datasette/static folder will be picked up immediately (though you may need to do a force-refresh in your browser to see changes to CSS or JavaScript). If you want to change Datasette's Python code you can use the --reload option to cause Datasette to automatically reload any time the underlying code changes: datasette --reload fixtures.db You can also use the fixtures.py script to recreate the testing version of metadata.json used by the unit tests. To do that: python tests/fixtures.py fixtures.db fixtures-metadata.json Or to output the plugins used by the tests, run this: python tests/fixtures.py fixtures.db fixtures-metadata.json fixtures-plugins Test tables written to fixtures.db - metadata written to fixtures-metadata.json Wrote plugin: fixtures-plugins/register_output_renderer.py Wrote plugin: fixtures-plugins/view_name.py Wrote plugin: fixtures-plugins/my_plugin.py Wrote plugin: fixtures-plugins/messages_output_renderer.py Wrote plugin: fixtures-plugins/my_plugin_2.py Then run Datasette like this: datasette fixtures.db -m fixtures-metadata.json --plugins-dir=fixtures-plugins/","[""Contributing""]",[] contributing:devenvironment,contributing,devenvironment,Setting up a development environment,"If you have Python 3.8 or higher installed on your computer (on OS X the quickest way to do this is using homebrew ) you can install an editable copy of Datasette using the following steps. If you want to use GitHub to publish your changes, first create a fork of datasette under your own GitHub account. Now clone that repository somewhere on your computer: git clone git@github.com:YOURNAME/datasette If you want to get started without creating your own fork, you can do this instead: git clone git@github.com:simonw/datasette The next step is to create a virtual environment for your project and use it to install Datasette's dependencies: cd datasette # Create a virtual environment in ./venv python3 -m venv ./venv # Now activate the virtual environment, so pip can install into it source venv/bin/activate # Install Datasette and its testing dependencies python3 -m pip install -e '.[test]' That last line does most of the work: pip install -e means ""install this package in a way that allows me to edit the source code in place"". The .[test] option means ""use the setup.py in this directory and install the optional testing dependencies as well"".","[""Contributing""]","[{""href"": ""https://docs.python-guide.org/starting/install3/osx/"", ""label"": ""is using homebrew""}, {""href"": ""https://github.com/simonw/datasette/fork"", ""label"": ""create a fork of datasette""}]" contributing:general-guidelines,contributing,general-guidelines,General guidelines,"main should always be releasable . Incomplete features should live in branches. This ensures that any small bug fixes can be quickly released. The ideal commit should bundle together the implementation, unit tests and associated documentation updates. The commit message should link to an associated issue. New plugin hooks should only be shipped if accompanied by a separate release of a non-demo plugin that uses them.","[""Contributing""]",[] contributing:id1,contributing,id1,Contributing,"Datasette is an open source project. We welcome contributions! This document describes how to contribute to Datasette core. You can also contribute to the wider Datasette ecosystem by creating new Plugins .",[],[] csv_export:csv-export-url-parameters,csv_export,csv-export-url-parameters,URL parameters,"The following options can be used to customize the CSVs returned by Datasette. ?_header=off This removes the first row of the CSV file specifying the headings - only the row data will be returned. ?_stream=on Stream all matching records, not just the first page of results. See below. ?_dl=on Causes Datasette to return a content-disposition: attachment; filename=""filename.csv"" header.","[""CSV export""]",[] csv_export:id1,csv_export,id1,CSV export,"Any Datasette table, view or custom SQL query can be exported as CSV. To obtain the CSV representation of the table you are looking, click the ""this data as CSV"" link. You can also use the advanced export form for more control over the resulting file, which looks like this and has the following options: download file - instead of displaying CSV in your browser, this forces your browser to download the CSV to your downloads directory. expand labels - if your table has any foreign key references this option will cause the CSV to gain additional COLUMN_NAME_label columns with a label for each foreign key derived from the linked table. In this example the city_id column is accompanied by a city_id_label column. stream all rows - by default CSV files only contain the first max_returned_rows records. This option will cause Datasette to loop through every matching record and return them as a single CSV file. You can try that out on https://latest.datasette.io/fixtures/facetable?_size=4",[],"[{""href"": ""https://latest.datasette.io/fixtures/facetable.csv?_labels=on&_size=max"", ""label"": ""In this example""}, {""href"": ""https://latest.datasette.io/fixtures/facetable?_size=4"", ""label"": ""https://latest.datasette.io/fixtures/facetable?_size=4""}]" csv_export:streaming-all-records,csv_export,streaming-all-records,Streaming all records,"The stream all rows option is designed to be as efficient as possible - under the hood it takes advantage of Python 3 asyncio capabilities and Datasette's efficient pagination to stream back the full CSV file. Since databases can get pretty large, by default this option is capped at 100MB - if a table returns more than 100MB of data the last line of the CSV will be a truncation error message. You can increase or remove this limit using the max_csv_mb config setting. You can also disable the CSV export feature entirely using allow_csv_stream .","[""CSV export""]",[] custom_templates:css-classes-on-the-body,custom_templates,css-classes-on-the-body,CSS classes on the ,"Every default template includes CSS classes in the body designed to support custom styling. The index template (the top level page at / ) gets this: The database template ( /dbname ) gets this: The custom SQL template ( /dbname?sql=... ) gets this: A canned query template ( /dbname/queryname ) gets this: The table template ( /dbname/tablename ) gets: The row template ( /dbname/tablename/rowid ) gets: The db-x and table-x classes use the database or table names themselves if they are valid CSS identifiers. If they aren't, we strip any invalid characters out and append a 6 character md5 digest of the original name, in order to ensure that multiple tables which resolve to the same stripped character version still have different CSS classes. Some examples: ""simple"" => ""simple"" ""MixedCase"" => ""MixedCase"" ""-no-leading-hyphens"" => ""no-leading-hyphens-65bea6"" ""_no-leading-underscores"" => ""no-leading-underscores-b921bc"" ""no spaces"" => ""no-spaces-7088d7"" ""-"" => ""336d5e"" ""no $ characters"" => ""no--characters-59e024"" and elements also get custom CSS classes reflecting the database column they are representing, for example:
id name
1 SMITH
","[""Custom pages and templates""]",[] custom_templates:custom-pages-404,custom_templates,custom-pages-404,Returning 404s,"To indicate that content could not be found and display the default 404 page you can use the raise_404(message) function: {% if not rows %} {{ raise_404(""Content not found"") }} {% endif %} If you call raise_404() the other content in your template will be ignored.","[""Custom pages and templates""]",[] custom_templates:custom-pages-errors,custom_templates,custom-pages-errors,Custom error pages,"Datasette returns an error page if an unexpected error occurs, access is forbidden or content cannot be found. You can customize the response returned for these errors by providing a custom error page template. Content not found errors use a 404.html template. Access denied errors use 403.html . Invalid input errors use 400.html . Unexpected errors of other kinds use 500.html . If a template for the specific error code is not found a template called error.html will be used instead. If you do not provide that template Datasette's default error.html template will be used. The error template will be passed the following context: status - integer The integer HTTP status code, e.g. 404, 500, 403, 400. error - string Details of the specific error, usually a full sentence. title - string or None A title for the page representing the class of error. This is often None for errors that do not provide a title separate from their error message.","[""Custom pages and templates"", ""Custom redirects""]","[{""href"": ""https://github.com/simonw/datasette/blob/main/datasette/templates/error.html"", ""label"": ""default error.html template""}]" custom_templates:custom-pages-headers,custom_templates,custom-pages-headers,Custom headers and status codes,"Custom pages default to being served with a content-type of text/html; charset=utf-8 and a 200 status code. You can change these by calling a custom function from within your template. For example, to serve a custom page with a 418 I'm a teapot HTTP status code, create a file in pages/teapot.html containing the following: {{ custom_status(418) }} Teapot I'm a teapot To serve a custom HTTP header, add a custom_header(name, value) function call. For example: {{ custom_status(418) }} {{ custom_header(""x-teapot"", ""I am"") }} Teapot I'm a teapot You can verify this is working using curl like this: curl -I 'http://127.0.0.1:8001/teapot' HTTP/1.1 418 date: Sun, 26 Apr 2020 18:38:30 GMT server: uvicorn x-teapot: I am content-type: text/html; charset=utf-8","[""Custom pages and templates""]",[] custom_templates:custom-pages-parameters,custom_templates,custom-pages-parameters,Path parameters for pages,"You can define custom pages that match multiple paths by creating files with {variable} definitions in their filenames. For example, to capture any request to a URL matching /about/* , you would create a template in the following location: templates/pages/about/{slug}.html A hit to /about/news would render that template and pass in a variable called slug with a value of ""news"" . If you use this mechanism don't forget to return a 404 if the referenced content could not be found. You can do this using {{ raise_404() }} described below. Templates defined using custom page routes work particularly well with the sql() template function from datasette-template-sql or the graphql() template function from datasette-graphql .","[""Custom pages and templates""]","[{""href"": ""https://github.com/simonw/datasette-template-sql"", ""label"": ""datasette-template-sql""}, {""href"": ""https://github.com/simonw/datasette-graphql#the-graphql-template-function"", ""label"": ""datasette-graphql""}]" custom_templates:custom-pages-redirects,custom_templates,custom-pages-redirects,Custom redirects,"You can use the custom_redirect(location) function to redirect users to another page, for example in a file called pages/datasette.html : {{ custom_redirect(""https://github.com/simonw/datasette"") }} Now requests to http://localhost:8001/datasette will result in a redirect. These redirects are served with a 302 Found status code by default. You can send a 301 Moved Permanently code by passing 301 as the second argument to the function: {{ custom_redirect(""https://github.com/simonw/datasette"", 301) }}","[""Custom pages and templates""]",[] custom_templates:customization,custom_templates,customization,Custom pages and templates,Datasette provides a number of ways of customizing the way data is displayed.,[],[] custom_templates:customization-css,custom_templates,customization-css,Writing custom CSS,"Custom templates need to take Datasette's default CSS into account. The pattern portfolio at /-/patterns ( example here ) is a useful reference for understanding the available CSS classes. The core class is particularly useful - you can apply this directly to a or