This is the backend code for Anonygram, an image board that allows users to explore and contribute to their current metros without the pressure to make an account or follow anyone.
Returns an array of image posts that were submitted within a specified distance of the queried latitude and longitude. If there are no submissions within the query parameters, then the server makes a call to the Google Places API and returns an array of up to 20 images of businesses in the area.
Sample query
/api/images/?sort={SORTBY}&lat={LATITUDE}&lon={LONGITUDE}&distance={DISTANCE}{SORTBY}- either new, where the response is ordered by timestamp, or top, where the response is ordered by the number of karma (i.e. upvotes){LATITUDE}- the latitude of the query location, which can be provided by the HTML5 Geolocation API{LONGITUDE}- the longitude of the query location, which can be provided by the HTML5 Geolocation API{DISTANCE}- the distance in kilometers within the query location to find image posts. If not included in the query, the distance defaults to 20km.
Example response
[
{
"id": 42,
"image_text": "amazing waterslide across the street!",
"image_url": "https://anonygram-images.s3.amazonaws.com/58f5951ccc35f88f3594172657d81f31",
"karma_total": 3,
"latitude": "51.482",
"longitude": "-0.007",
"user_id": "7ad87401-dda8-48f0-8ed8-a6bc9756e53c",
"create_timestamp": "2019-12-12T17:58:03.868Z",
}
]id- string- uuid of an image postimage_text- string- the description, flavor text, or caption of an image postimage_url- string- URL of where the image is hosted on Anonygram's S3 serverkarma_total- integer- the number of upvotes that an image post haslatitude- float- latitude of the image post's location *longitude- float- longitude of the image post's location *user_id- string- uuid of the user that submitted the image post (returns null if it is an anonymous post from an unregistered user)create_timestamp- string- timestamp in ISO format denoting when the post was submitted
* note that latitude and longitude are truncated to 3 decimal places to maintain anonymity
A typical image submission is made via a POST request using the multipart/form-data encoding type in a form submit. The uploaded file must have a file extension of either jpeg, jpg, png, gif. The server compresses the transmitted data to JPEG format, auto-rotates it based on the image's EXIF metadata (i.e. if the image were taken in portrait mode on an iPhone), and then stores the image on Anonygram's S3 server. The resulting URL that points to the asset on S3 is stored as a field in the images table within Anonygram's database.
If the user making the image submission is registered and logged in, their user_id is stored with the image in the database. This allows the user to delete their submission later, which is documented in the DELETE request below.
Example request
{
body: {
image_text: 'amazing waterslide across the street!',
latitude: '51.4825766',
longitude: '-0.0076589'
},
user: {
id: '7ad87401-dda8-48f0-8ed8-a6bc9756e53c',
username: 'admin',
password: '$2a$12$WtU7R79oJnrqDqVpGlDSyuvk5ELkkrk8uOZ3ki6CkRlP.SP6p6G8y',
karma_balance: 25
},
file: {
fieldname: 'someImage',
originalname: 'waterslide.png',
encoding: '7bit',
mimetype: 'image/png',
destination: 'uploads/',
filename: '58f5951ccc35f88f3594172657d81f31',
path: 'uploads\\58f5951ccc35f88f3594172657d81f31',
size: 141628
}
}A successful POST requires a latitude, longitude, and the image file itself. Latitude and longitude can be provided by the HTML5 Geolocation API.
The submitted image must meet community guidelines and will be rejected with a status
400if questionable content is detected by the Google Vision API.
This endpoint upvotes an image submission specified by submission_id, by incrementing the image's karma_total by 1. The upvoter must be a registered and logged in user with a positive karma_balance. Additionally, the submission's user_id must match the upvoter's id, otherwise the server responds with a status 403 (i.e. users may not upvote their own submissions).
If no submission could be found by submission_id, the server responds with a status 400.
This endpoint allows a registered and logged in user to remove an image that they posted from the database, specified by submission_id. If the id of the user making the DELETE request does not match the user_id of the submission, the server responds with a status 401.
If no submission could be found by submission_id, the server responds with a status 400.
Returns an array of comments associated with an image submission specified by submission_id. Every comment contains a user_id of the user that posted the comment, but the displayed username is randomly generated on the client to maintain anonymity.
If no submission could be found by submission_id, the server responds with a status 404.
Example response
[
{
"comment_id": "fcf3fa7b-a1ca-4314-bbd5-5dba75ba5991",
"comment_text": "wow that's wild!",
"comment_timestamp": "2019-12-12T23:32:14.876Z",
"submission_id": 42,
"user_id": "7ad87401-dda8-48f0-8ed8-a6bc9756e53c"
}
]comment_id- string- uuid of a commentcomment_text- string- the contents of a posted commentcomment_timestamp- string- timestamp in ISO format denoting when the comment was createdsubmission_id- integer- the id of an image submission that the comment was posted touser_id- string- uuid of the user that posted the comment
This endpoint allows a registered and logged in user to post a comment to an image submission specified by submission_id.
If no submission could be found by submission_id, the server responds with a status 404.
Example request
{
"user_id": "7ad87401-dda8-48f0-8ed8-a6bc9756e53c",
"comment_text": "wow that's wild!"
}Returns the data for the user specified by user_id.
If no user could be found by user_id, the server responds with a status 400.
Example response
{
"id": "7ad87401-dda8-48f0-8ed8-a6bc9756e53c",
"karma_balance": 25
}The karma_balance (i.e. the number of remaining upvotes that a user has) of each registered user in the Anonygram database is reset to 25 every hour, whether or not any karma was spent in that hour.
Note that the
usernameof the specified user is not included in the response so as to maintain anonymity.
- Express for handling API requests
- Node for interacting with the file system
- Multer for handling file uploads
- AWS SDK for interfacing with Amazon's S3 service
- Sharp for image manipulation / compression
- Google Vision for image recognition / content arbitration
- Google Places for retrieving local business images
- Knex.js for interfacing with the PostgreSQL database
- Postgrator for database migration
- Mocha, Chai, Supertest for endpoints testing
- JSON Web Token, bcryptjs for user authentication / authorization