The b(ack)log

If you haven’t already, take a look at part 1 and 2 and part 3.

Let’s start again, but this time instead of copy and pasting the code, we’ll copy some files from the web to our own site. Go to the empty IPFS folder using Agregore Browser, open your dev tools (Ctrl+Shift+I) and go to the console.

First we’ll create a function that takes an array of File objects and adds it to our site. To add multiple files at once, we need to use a PUT request with a FormData instance as the body. The FormData object will contain a list of the files we’re adding. You can read the more about this on the documentation site.

async function addFiles(files){
    const formData = new FormData()
    files.forEach( (file, index) => {
       formData.append('file', file) 
    })
    const resp = await fetch(window.origin, {method: 'put', body: formData})
    const newLocation = resp.headers.get('location')
    window.location = new URL(newLocation).origin
}

And now let’s get the index.html and lib.js from the web and add them to our site using the function we just defined.

let resp = await fetch('https://www.thebacklog.net/projects/agregore-web-apps/amt3.js')
const libjs = await resp.text()
resp = await fetch('https://www.thebacklog.net/projects/agregore-web-apps/amt3-index.tmpl')
const indexhtml = await resp.text()

addFiles([
    new File([indexhtml], 'index.html', {type: 'text/html'}),
    new File([libjs], 'lib.js', {type: 'text/javascript'}),
])

The last piece that we are still missing to have a usable website is giving it an address. You’ve probably noticed that each time we’ve made a change to our site, the address changed to a new address in the format ipfs://blahblahtoolongandunreadabletoreallypayattentionlinknoteveninthebio. If we want to share our site with other people, we need an unchanging URL to share with other people.

To do that, we can publish our site using a key and obtain an IPNS address that stays the same!!

Lets create the key:

let resp = await fetch('ipns://localhost/?key=mysite', {method: 'POST'})
const key = resp.headers.get('location')

The value of key is the IPNS address that we can share with other people. It will start with the protocol part of the URL ipns:// followed by alpha numeric characters.

We’ve created the key, but it doesn’t yet point at anything. Let’s point it at the ipfs:// address of our site. This can take a while (~30s) so be patient.

resp = await fetch(key, {method: 'POST', body: window.origin})

Once the request succeeds, you can visit your published site by going to the ipns://... URL or by running window.location = key in the console. You can also use an IPFS capable browser on a different device to view the site.

Lets see if we can update the site from the IPNS URL. Run showEditor() in the console, make an edit to index.html and see what happens.

That took a while and didn’t succeed. Looking at the error message in the console, it seems the error is on line 3 of the updateSite function, we hard coded the protocol part of the URL we’re using in fetch. Lets fix that now. Since we can’t save, we need to go back to the last version with an ipfs://... URL. Then change the updateSite function as follows:

async function updateSite(filename, content){
    const resp = await fetch(`${window.origin}/${filename}`, {method: 'put', body: content})
    const newLocation = resp.headers.get('location')
    window.location = new URL(newLocation).origin

Before we publish the site again, let’s add that functionality to ‘lib.js’. Add the following function:

async function publishSite(){
    let resp = await fetch('ipns://localhost/?key=mysite', {method: 'POST'})
    const key = resp.headers.get('location')
    resp = await fetch(key, {method: 'POST', body: window.origin})
    window.location = new URL(resp.headers.get('location')).origin
}

Now run publishSite() in the console, again it will take some time to work. But now once you’re redirected to your site you should be able to update the ipns site!

And lastly, lets add a button to publish our site. Add the following code to the showEditor function:

if (window.origin.startsWith('ipfs://')){
    const button = document.createElement('button')
    button.innerHTML = 'Publish site'
    button.onclick = e => {
        e.preventDefault()
        publishSite()
    }
    sidebar.appendChild(button)
}

Here is the final code of lib.js:

async function publishSite(){
    let resp = await fetch('ipns://localhost/?key=mysite', {method: 'POST'})
    const key = resp.headers.get('location')
    resp = await fetch(key, {method: 'POST', body: window.origin})
    window.location = new URL(resp.headers.get('location')).origin
}

async function updateSite(filename, content){
    const resp = await fetch(`${window.origin}/${filename}`, {method: 'put', body: content})
    const newLocation = resp.headers.get('location')
    window.location = new URL(newLocation).origin
}

async function loadFile(filename){
    const resp = await fetch(filename)
    const content = await resp.text()
    document.getElementById('idFilenameInput').value = filename
    document.getElementById('idContentInput').value = content
}

async function listDir(path){
    const resp = await fetch(window.origin + '?noResolve')
    const files = await resp.json()
    return files
}

async function showEditor(){
    let editorDiv = document.getElementById("editor")
    if (!editorDiv){
        editorDiv = document.createElement('div')
        editorDiv.id = 'editor'
    }
    editorDiv.style = `display: flex;
        flex-direction: column;
        position: absolute;
        top: 0;
        left: 0;
        width: 100vw;
        height: 100vh;
        background-color: rgb(233 233 233 / 95%);
    `
    editorDiv.innerHTML = `<div style="display: flex; flex-grow: 1; padding: 1em">
        <div id="idSidebar" style="padding-right: 1em; min-width: 20vw;"><h2>Files</h2>
        </div>
        <form id="idForm" style="flex-grow: 1; display: flex; flex-direction: column;">
            <label for="idFilenameInput">Filename</label>
            <input type="text" name="filename" id="idFilenameInput"></input>
            <label for="idContentInput">Content</label>
            <textarea id="idContentInput" style="flex-grow: 1;" rows="20"></textarea>
            <input type="submit" value="Save"></input>
        </form>
    </div>`
    document.body.appendChild(editorDiv)
    const form = document.getElementById('idForm')
    form.onsubmit = e => {
        e.preventDefault()
        const filename = document.getElementById('idFilenameInput').value
        const content = document.getElementById('idContentInput').value
        updateSite(filename, content)
    }
    const sidebar = document.getElementById('idSidebar')
    const files = await listDir(window.origin)
    const list = document.createElement('ul')
    list.style =  "list-style: none; padding-inline-start: 0;"
    files.map( file => {
        let li = document.createElement('li')
        li.innerHTML = `<a href="#">${file}</a>`
        li.querySelector('a').onclick = e => loadFile(file)
        list.appendChild(li)
    })
    sidebar.appendChild(list)
    if (window.origin.startsWith('ipfs://')){
        const button = document.createElement('button')
        button.innerHTML = 'Publish site'
        button.onclick = e => {
            e.preventDefault()
            publishSite()
        }
        sidebar.appendChild(button)
    }
}