How can I get metadata for an epub?

[Jemeni11]

I want to get basic stuff like the author's name, publisher, description, etc. Is there any way of doing this???

[kravchenko-anton]

Hey, in you project work useReader hook?

[kravchenko-anton]

Mee too needed metadata

[Jemeni11]

Hey, in you project work useReader hook?

No, I am not

[D3troit98]

Anyone figured a way on this? Or should we have to edit the code

[siphu]

You'll have to edit the template or patch the default template to get the meta data.
inside the book.ready, you can add something like -

window.ReactNativeWebView.postMessage(JSON.stringify({ type: "meta", data: book.package.metadata }));

you'll also have to patch the View.tsx to also pass that data back to wherever you want to use it.

if you want to get the book cover, then you'll have to be more creative by -

1. reading the url through book.coverUrl()
2. converting it to a blob
3. using FileReader to convert it into a base64.

[kravchenko-anton]

Oh my good, you know any complete case for example?

[Jemeni11]

You'll have to edit the template or patch the default template to get the meta data. inside the book.ready, you can add something like -

window.ReactNativeWebView.postMessage(JSON.stringify({ type: "meta", data: book.package.metadata }));

you'll also have to patch the View.tsx to also pass that data back to wherever you want to use it.

if you want to get the book cover, then you'll have to be more creative by -

1. reading the url through book.coverUrl()
2. converting it to a blob
3. using FileReader to convert it into a base64.

Thanks !!!
I did this and it works.
Unfortunately, the book.coverUrl() doesn't work. It returns an empty object Object{}

[siphu]

@Jemeni11
this is what how I did it -

const meta = book.package.metadata;
book.coverUrl().then(async (url) => {
    var reader = new FileReader();
    reader.onload = (res) => { 
        window.ReactNativeWebView.postMessage(JSON.stringify({ type: "cover", cover: reader.result, meta: meta }));
    }
    reader.readAsDataURL(await fetch(url).then(res => res.blob()));
  }).catch(()=>{
    window.ReactNativeWebView.postMessage(JSON.stringify({ type: "cover", cover: undefined, meta: meta }));
  });

[Jemeni11]

Once again, thanks !!! This worked!!

I made a pull request adding this feature: #73

[kravchenko-anton]

How can I get the metadata for a book that the user won't open?
for example the user hasn't opened the book and how can I get the book's metadata right away. It is also interesting whether it is possible to make the translation functionality of the book?
and how can you do offline reading guys?

[Jemeni11]

How can I get the metadata for a book that the user won't open?
for example the user hasn't opened the book and how can I get the book's metadata right away. It is also interesting whether it is possible to make the translation functionality of the book?

I do not know how to do this with this library but you can use xmldom and do something like this:

const { DOMParser } = require("@xmldom/xmldom");

let xmlMetadata;

export async function parseXML(xmlFile) {
  try {
    const response = await fetch(xmlFile);
    const xmlText = await response.text();
    const parser = new DOMParser();
    const xmlDoc = parser.parseFromString(xmlText, "application/xml");  // "application/xml" or "text/xml"

    xmlMetadata = {
      title: xmlDoc.getElementsByTagName("dc:title")[0].textContent,
      author: xmlDoc.getElementsByTagName("dc:creator")[0].textContent,
      date: xmlDoc.getElementsByTagName("dc:publisher")[0].textContent,
    };
    return xmlMetadata;
  } catch (error) {
    console.error(`Error parsing XML: ${error}`);
  }
}

where xmlFile is the path to the .opf file of the epub.

Of course you'll need to unzip the epub to even get to the .opf file in the first place and I don't know how to do that.

[Jemeni11]

and how can you do offline reading guys?

I ... did not notice this. Are you saying this library only works if there's an internet connection?

[Jemeni11]

Of course you'll need to unzip the epub to even get to the .opf file in the first place and I don't know how to do that.

UPDATE:
You can use any of these libraries:

• Epub-ocf
• Adm-zip
• JSZip

You'll have to read the docs because I only skimmed through but from what I saw they should work.

I even tested JSZip and it printed out the correct output

[kravchenko-anton]

I tried these three libraries but they either do not work with react native expo or they are long out of date, can you please show me an example code that could unzip epub like on JSZip site?
Thank you very much and sorry, I am new to react native

Of course you'll need to unzip the epub to even get to the .opf file in the first place and I don't know how to do that.

UPDATE: You can use any of these libraries:

• Epub-ocf
• Adm-zip
• JSZip

You'll have to read the docs because I only skimmed through but from what I saw they should work.

I even tested JSZip and it printed out the correct output

[Jemeni11]

I tried these three libraries but they either do not work with react native expo or they are long out of date, can you please show me an example code that could unzip epub like on JSZip site? Thank you very much and sorry, I am new to react native

Of course you'll need to unzip the epub to even get to the .opf file in the first place and I don't know how to do that.

UPDATE: You can use any of these libraries:

• Epub-ocf
• Adm-zip
• JSZip

You'll have to read the docs because I only skimmed through but from what I saw they should work.
I even tested JSZip and it printed out the correct output

Hey @Anton-Kravkenko
I made an app using JSZip and Expo
Here's the repo: https://github.com/Jemeni11/ePub-file-details
When an ePub is selected, the app lists out all the files in the epub.

[kravchenko-anton]

Oh my good, thank you

[kravchenko-anton]

I fixed the problem of difference epub files and missing components using google book api, title is in all, with it I did it. There is no other choice, almost all applications for reading books use this approach