Post local image to facebook group via Graph API - reactjs

Question

I'm working on a React project with Facebook user integration.
I need to post a client-side generated image to a private group on behalf of the logged-in user.
Using the {group-id}/photo endpoint I can successfully post a picture which already exists on the web providing the url and caption parameters:
const postImageUrlToFacebook = () => {
const url = "https://upload.wikimedia.org/wikipedia/commons/e/e0/New.gif";
let caption = "test upload url image from React";
httpFacebookGraphClient(facebookToken)
.post("/" + ldlTestFacebookGroupId + "/photos", { url, caption })
.then((res) => {
console.log(res.data);
})
.catch((err) => {
console.log(err);
});
};
The definition of the httpFacebookGraphClient is the following:
import axios, { AxiosRequestConfig } from "axios";
const httpFacebookGraphClient = (token: string | null) => {
const defaultOptions = {
baseURL: "https://graph.facebook.com/v14.0",
method: "get",
// withCredentials: true,
headers: {
"Content-Type": "application/json",
},
};
// Create instance
let instance = axios.create(defaultOptions);
// Set the access token parameter for any request
instance.interceptors.request.use((config: AxiosRequestConfig): AxiosRequestConfig => {
if (!config) {
config = {};
}
if (!config.params) {
config.params = {};
}
config.params.access_token = token;
config.params.limit = "999";
return config;
});
return instance;
};
export default httpFacebookGraphClient;
I would now need to start from a default svg, modifiy some g tags inside of it via javascript, convert to jpg and post it to a facebook group.
Let's suppose the starting SVG is the following:
<svg id="Livello_1" data-name="Livello 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 150 107"><defs><style>.cls-1,.cls-3,.cls-4,.cls-5{fill:#ffc000;}.cls-2{fill:#fff;}.cls-3,.cls-4,.cls-5{stroke:#fff;stroke-miterlimit:10;}.cls-3{stroke-width:0.87px;}.cls-4{stroke-width:0.79px;}.cls-5{stroke-width:0.65px;}</style></defs><title>bannerino scegli il tuo sconto</title><path class="cls-1" d="M136.88,2.63a10,10,0,0,1,10,10V94.37a10,10,0,0,1-10,10H13.13a10,10,0,0,1-10-10V12.63a10,10,0,0,1,10-10H136.88m0-2H13.13a12,12,0,0,0-12,12V94.37a12,12,0,0,0,12,12H136.88a12,12,0,0,0,12-12V12.63a12,12,0,0,0-12-12h0Z"/></svg>
I started from the end, trying to post a local image to the Facebook group before trying to build the image, but I'm already stuck.
Reading the Facebook api docs at this link I found this sentence on the url parameter;
The URL of a photo that is already uploaded to the Internet. You must specify this or a file attachment
mentioning a file attachment.
Again on the Facebook docs I found this that explain how to upload a file to Facebook to use it in subsequent api calls, but I can't make it to work.
Anyone could give me a hint on how to proceed?

Answer 1

I found the way around this and I can successfully post an image selected by input field client side.
React component state:
const [fileToUpload, setFileToUpload] = useState<any>();
inputFileChangeHandler:
const inputFileChangeHandler = (event: React.ChangeEvent<HTMLInputElement>) => {
if (event.currentTarget != null && event.currentTarget.files != null) {
setFileToUpload(event.currentTarget.files[0]);
}
};
uploadImageToFacebook:
const uploadImageToFacebook = () => {
let caption = "test upload local image from React";
const fileReader = new FileReader();
fileReader.onloadend = async () => {
if (fileReader.result != null) {
const photoData = new Blob([fileReader.result], { type: "image/png" });
const formData = new FormData();
formData.append("source", photoData);
formData.append("caption", caption);
httpFacebookGraphClient(facebookToken)
.post("/" + ldlTestFacebookGroupId + "/photos", formData, {
headers: {
"Content-Type": "multipart/form-data",
},
})
.then((res) => {
console.log(res.data);
})
.catch((err) => {
console.log(err);
});
}
};
fileReader.readAsArrayBuffer(fileToUpload);
};
On jsx:
<input type="file" id="file-input" onChange={inputFileChangeHandler} />
<button onClick={uploadImageToFacebook}>Invia</button>