crowdsourced-map

crowdsourced-map (Demo) is a simple map application that allows anyone to add pins to a public map. There are no frameworks, packages, or servers involved. It uses a Google Form as its backend, so you can host it anywhere you can host a few HTML/CSS/JS files. You can even just .zip up the project and send it to users.

The project was originally developed for a literacy non-profit that wanted readers to add their favourite books to a map, based on the book's setting. I've written a walkthrough below with someone who works at that non-profit in mind: someone who doesn't code, and would not be comfortable setting up a server to run the back-end for a similar application. More advanced users might find the walkthrough a little slow-paced, but it will get you set up nonetheless.

crowdsourced-map is free under the MIT License, but Google requires that you pay for the use of its Maps API. They offer $200 of free credit each month, which should cover most use-cases for an application like this one. Be advised Google requires that you provide a credit card to use this free credit. You can set up and test crowdsourced-map without signing up for a Google Maps API key, but you will need one by the time you publish the app.

A note on scale

Since crowdsourced-map doesn't use a typical backend, it is not possible to enforce any real security measures around data submission. Only use crowdsourced-map in environments where you are expecting a small audience, such as a local fundraising drive, personal project, or a school assignment. Even after you take these precautions, an attacker can always insert bad data due to the crowdsourced nature of the map. Removing malicious entries is easy, but please be aware of the risk.

Walkthrough

1. Get a copy of crowdsourced-map

If you're familar with Git, clone this repo. If you're not, click Clone or Download, Download ZIP, then unzip the downloaded file. Delete the docs folder.

2. Set up your Google Form

To begin using crowdsourced-map, you need to set up the Google Form that will serve as the back-end for the app. Create a new Google Form in Google Drive and add the fields you would like users to be able to enter. The original crowdsourced-map allowed users to enter their own name, the name of a book they read, the author of that book, and finally a "Location" field for the book's setting. You can pick whatever fields suit your use case, but you must include "Location", "Latitude", and "Longitude" fields. crowdsourced-map is easiest to use if you pick three custom fields in addition to the Location/Latitude/Longitude fields. With that said, you can use any number of fields with some editing. If you use a corporate Google account, make sure that your form can be filled by someone outside your organization. Do this by clicking the gear icon on the Edit Form page and unchecking the appropriate box.

Forget about how it looks!

Don't worry about the Latitude/Longitude fields or how the Google Form looks; the user will never see them.

3. Set up your Google Sheet

Once your Google Form is complete, make sure it is sending its results to a Google Sheet. You can find the Sheet by clicking on the Responses tab of the Edit Form page and clicking the green Sheets icon. Once the Sheet is open, go to File > Publish to Web... and click Publish. Close the Publish box and click the Share button at the top right. Turn link sharing on, and make sure "Anyone with the link can view" is selected. Make a note of the link and in particular the spreadsheet ID. The spreadsheet ID is the long alphanumeric code betqween /d/ and /edit. For instance, if your sharable link is https://docs.google.com/spreadsheets/d/1MkdonOT3oP4ofwgM_9DL3njkBNrcValWMt-X-WKveDI/edit?usp=sharing, the spreadsheet ID is 1MkdonOT3oP4ofwgM_9DL3njkBNrcValWMt-X-WKveDI. In your copy of crowdsourced-map, add the spreadsheet ID to the const spreadsheetID = line in scripts/map.js.

4. Gather your Google Form data

You will need to gather some data from your Google Form. Open your Form, and enter your browser's developer tools. If you're not sure how to do this, Google instructions for the browser you use. Most modern developer tools place an icon that resembles a cursor entering a box in the top-left corner of the window. Click that icon, and then click on one of the text boxes on your Form. The developer tools will highlight the code behind that text box. Here is an example: In the line of code highlighted, make a note of the value for name=. In the screenshot above, it is entry.870886307. Repeat this for every input on the form. Finally, search in the developer tools inspector for /formResponse. A URL will be highlighted. Take a note of this URL. Example:

5. Input your Form data into your website

You will now use the data you gathered in step 4 to make crowdsourced-map come to life. Open your copy of index.html. Make the following changes:

• On line 27, where the <form> element begins, replace the action= value with the /formResponse URL you gathered in step 4.
• Following line 27 are small repeated blocks of code, wrapped in <div class="book-input"> tags. Replace the name= value on the <input> tag in the block with the corresponding entry.XXXXXXXXX value you grabbed in step 4. Take this take to update the text in the input's <label> as well. At this point, you should have a functioning application. Just open the index.html file in a web browser, and you should be able to add values to the map. That said, some map features will be disabled since you have not yet gotten permission (an API key) from Google to use the map.

6. Acquire a Google Maps API key

Follow step 1 of Google's tutorial on acquiring an API key. You will be prompted to add referrers during the setup process. Add the URL of the site at which you will be hosting your map, so that others cannot use your key. You will need both the Javascript Maps API and the Places API. Once you have your API key, open index.html. Add your key to line 9, remove line 8 above, and remove the comment symbols (arrows) around line 9. Your site is now complete!

7. Distribute your site

If you work in an environment with a systems adminstrator or IT person, give them your copy of the crowdsourced-map folder. The simplest way to distribute your site without outside help is to simply send your users a copy of the crowdsourced-map folder. This is admittedly low-tech, but is useful for testing or deploying your site to very small groups of friends or colleagues. The easiest method to publish your site "for real" is to use GitHub Pages. This process begins with uploading your copy of crowdsourced-map to GitHub. A full explanation of how to do this or how to configure GitHub Pages is beyond the scope of this tutorial, but GitHub offers a Help Centre with instructions, and many tutorials can be found online.

This concludes the walkthrough. If you get stuck, or have outstanding questions, feel free to email me at [email protected].