Svelte Reader - an easy way to embed a ePub into your webapp
An svelte-reader for svelte powered by EpubJS
Document
Basic usage
npm install svelte-reader --save
And in your svelte-component...
<script>
import { SvelteReader } from "svelte-reader";
</script>
<div style="height: 100vh">
<SvelteReader url="/files/啼笑因缘.epub" />
</div>
SvelteReader Attributes
Name | Description | Type | Default |
---|---|---|---|
url | book url or arrayBuffer |
string /ArrayBuffer
|
— |
title | the title of the book | string |
— |
showToc | whether to show the toc | boolean |
true |
SvelteReader Slots
Name | Description |
---|---|
title | You have access to title by slot |
SvelteReader props passed to inner EpubView
EpubView Attributes
Name | Description | Type | Default |
---|---|---|---|
url | the path or arrayBuffer of the book |
string /ArrayBuffer
|
— |
location | set / update location of the epub |
string /number
|
— |
tocChanged | when the reader has parsed the book you will receive an array of the chapters | function(toc) |
— |
handleKeyPress | when press the key | function(event) |
|
handleTextSelected | when select text | function(cfiRange,contents) |
|
epubInitOptions | pass custom properties to the epub init function, see epub.js | object |
— |
epubOptions | pass custom properties to the epub rendition, see epub.js's book.renderTo function | object |
— |
getRendition | when epubjs has rendered the epub-file you can get access to the epubjs-rendition object here | function(rendition) |
— |
EpubView Events
Name | Description | Parameters |
---|---|---|
update:location | a function that receives the current location while user is reading. This function is called everytime the page changes, and also when it first renders. | the updated location |
EpubView Slots
Name | Description |
---|---|
loadingView | epub view loadingView |
EpubView Exposes
Name | Description | Type |
---|---|---|
nextPage | display next page | function |
prevPage | display previous page | function |
setLocation | Set the page | function(href) |
Recipes and tips
Save and retrieve progress from storage
Saving the current page on storage is pretty simple, but we need to keep in mind that locationChanged
also gets called on the very first render of our app.
<script>
import { SvelteReader } from "svelte-reader";
let location = localStorage.getItem("book-progress") || null;
let firstRenderDone = false;
const locationChange = (e) => {
const epubcifi = e.detail;
// Since this function is also called on initial rendering, we are using custom state
// logic to check if this is the initial render.
// If you block this function from running (i.e not letting it change the page on the first render) your app crashes.
if (!firstRenderDone) {
location = localStorage.getItem("book-progress");
return (firstRenderDone = true);
}
// This is the code that runs everytime the page changes, after the initial render.
// Saving the current epubcifi on storage...
localStorage.setItem("book-progress", epubcifi);
// And then rendering it.
location = epubcifi; // Or setLocation(localStorage.getItem("book-progress"))
};
</script>
<div style="height: 100vh">
<SvelteReader
url="/files/啼笑因缘.epub"
{location}
on:update:location={locationChange}
/>
</div>
Display page number for current chapter
We store the epubjs rendition in a ref, and get the page numbers in the callback when location is changed. Note that in this example we also find them name of the current chapter from the toc. Also see limitation for pagination for the whole book.
<script>
import { SvelteReader } from "svelte-reader";
let rendition = null,
toc = [];
let page = "";
const getRendition = (val) => (rendition = val);
const getLabel = (toc, href) => {
let label = "n/a";
toc.some((item) => {
if (item.subitems.length > 0) {
const subChapter = getLabel(item.subitems, href);
if (subChapter !== "n/a") {
label = subChapter;
return true;
}
} else if (item.href.includes(href)) {
label = item.label;
return true;
}
});
return label;
};
const locationChange = (e) => {
const epubcifi= e.detail
if (epubcifi) {
const { displayed, href } = rendition.location.start;
if (href !== "titlepage.xhtml") {
const label = getLabel(toc, href);
page = `${displayed.page}/${displayed.total} ${label}`;
}
}
};
</script>
<div style="height: 100vh">
<SvelteReader
url="/files/啼笑因缘.epub"
{getRendition}
tocChanged={val=>toc = val}
on:update:location={locationChange}
/>
</div>
<div class="page">
{ page }
</div>
<style>
.page {
position: absolute;
bottom: 1rem;
right: 1rem;
left: 1rem;
text-align: center;
z-index: 1;
color: #000;
}
</style>
Change font-size
Hooking into epubJS rendition object is the key for this also.
<script>
import { SvelteReader } from "svelte-reader";
let rendition = null;
let size = 100;
const changeSize = (val) => {
size = val;
rendition.themes.fontSize(`${val}%`);
};
const getRendition = (val) => {
rendition = val;
rendition.themes.fontSize(`${size}%`);
};
</script>
<div style="height: 100vh">
<SvelteReader url="/files/啼笑因缘.epub" {getRendition} />
</div>
<div class="size">
<button on:click={() => changeSize(Math.max(80, size - 10))}>-</button>
<span>Current size: {size}%</span>
<button on:click={() => changeSize(Math.min(130, size + 10))}>+</button>
</div>
<style>
.size {
position: absolute;
bottom: 1rem;
right: 1rem;
left: 1rem;
z-index: 1;
text-align: center;
color: #000;
}
</style>
Hightlight selection in epub
This shows how to hook into epubJS annotations object and let the user highlight selection and store this in a list where user can go to a selection or delete it.
<script>
import { onDestroy } from "svelte";
import { SvelteReader } from "svelte-reader";
let rendition = null;
let selections =[]
const setRenderSelection = (cfiRange, contents) => {
selections = [...selections,{text: rendition.getRange(cfiRange).toString(),cfiRange}];
rendition.annotations.add("highlight", cfiRange, {}, null, "hl", {
fill: "red",
"fill-opacity": "0.5",
"mix-blend-mode": "multiply",
});
contents.window.getSelection().removeAllRanges();
};
const getRendition = (val) => {
rendition = val;
rendition.themes.default({
"::selection": {
background: "orange",
},
});
rendition.on("selected", setRenderSelection);
};
const remove = (cfiRange, index) => {
rendition.annotations.remove(cfiRange, "highlight");
selections = selections.filter((item, j) => j !== index);
};
onDestroy(() => {
rendition.off("selected", setRenderSelection);
});
</script>
<div style="height: 100vh">
<SvelteReader url="/files/啼笑因缘.epub" {getRendition} />
</div>
<div class="selection">
Selection:
<ul>
{#each selections as { text, cfiRange }, index}
<li>
{text || ""}
<button on:click={() => rendition.display(cfiRange)}>show</button>
<button on:click={() => remove(cfiRange, index)}>x</button>
</li>
{/each}
</ul>
</div>
<style>
.selection {
position: absolute;
bottom: 1rem;
right: 1rem;
left: 1rem;
z-index: 1;
background-color: white;
color: #000;
}
</style>
Handling missing mime-types on server
EpubJS will try to parse the epub-file you pass to it, but if the server send wrong mine-types or the file does not contain .epub
you can use the epubInitOptions prop to force reading it right.
<script>
import { SvelteReader } from "svelte-reader";
</script>
<div style="height: 100vh">
<SvelteReader url="/my-epub-service" epubInitOptions={{ openAs: "epub" }} />
</div>
Display a scrolled epub-view
Pass options for this into epubJS in the prop epubOptions
<script>
import { SvelteReader } from "svelte-reader";
</script>
<div style="height: 100vh">
<SvelteReader
url="/files/啼笑因缘.epub"
epubOptions={{
flow: "scrolled",
manager: "continuous",
}}
/>
</div>
Enable opening links / running scripts inside epubjs iframe
Epubjs is rendering the epub-content inside and iframe which defaults to sandbox="allow-same-origin"
, to enable opening links or running javascript in an epub, you will need to pass some extra params in the epubOptions
prop.
<script>
import { SvelteReader } from "svelte-reader";
</script>
<div style="height: 100vh">
<SvelteReader
url="/files/啼笑因缘.epub"
epubOptions={{
allowPopups: true, // Adds `allow-popups` to sandbox-attribute
allowScriptedContent: true, // Adds `allow-scripts` to sandbox-attribute
}}
/>
</div>
Get book information
<SvelteReader url='/files/啼笑因缘.epub' getRendition={getRendition}>
</SvelteReader>
{#if information}
<div style='color: #000'>
<img src={information.cover} alt={information.title} style="width: 100px">
<p>标题:{information.title }</p>
<p>作者:{ information.creator }</p>
<p>出版社:{information.publisher }</p>
<p>语言:{ information.language }</p>
<p>出版日期:{ information.pubdate }</p>
<p>修改日期:{ information.modified_date }</p>
<p>介绍:{ information.description }</p>
</div>
{/if}
<script>
import { SvelteReader } from "svelte-reader";
let information = null
const getRendition = (rendition) => {
const book = rendition.book
book.ready.then(() => {
book.loaded.metadata.then(async (metadata) => {
const cover = await book.coverUrl()
information = { ...metadata, cover }
})
})
}
</script>
Import file
<script>
import { SvelteReader } from "svelte-reader";
let url = null;
const onchange = (e) => {
const file = e.target.files[0];
if (window.FileReader) {
var reader = new FileReader();
reader.onloadend = (e) => (url = reader.result);
reader.readAsArrayBuffer(file);
}
};
</script>
<div style="position: relative;height: 100vh;">
{#if url}
<div style="height: 100vh">
<SvelteReader {url} />
</div>
{/if}
<input
type="file"
multiple={false}
accept=".epub"
on:change={onchange}
class="input"
/>
</div>
<style>
.input {
position: absolute;
bottom: 1rem;
right: 1rem;
left: 1rem;
z-index: 1;
}
</style>
Current progress
<script>
import { SvelteReader } from "svelte-reader";
let current = 0;
let rendition, book, displayed;
const getRendition = (val) => {
rendition = val;
book = rendition.book;
displayed = rendition.display();
book.ready
.then(() => {
return book.locations.generate(1600);
})
.then((locations) => {
// Wait for book to be rendered to get current page
displayed.then(function () {
// Get the current CFI
var currentLocation = rendition.currentLocation();
// Get the Percentage (or location) from that CFI
const currentPage = book.locations.percentageFromCfi(
currentLocation.start.cfi
);
current = currentPage;
});
rendition.on("relocated", (location) => {
const percent = book.locations.percentageFromCfi(location.start.cfi);
const percentage = Math.floor(percent * 100);
current = percentage;
});
});
};
const change = (e) => {
const value = e.target.value;
current= value;
var cfi = book.locations.cfiFromPercentage(value / 100);
rendition.display(cfi);
};
</script>
<div style="position: relative">
<div style="height: 100vh">
<SvelteReader
getRendition={getRendition}
url="/files/啼笑因缘.epub"
/>
</div>
<div class="progress">
<input
type="number"
value={current}
min={0}
max={100}
on:change={change}
/>%
<input
type="range"
value={current}
min={0}
max={100}
step={1}
on:change={change}
/>
</div>
</div>
<style>
.progress {
position: absolute;
bottom: 1rem;
right: 1rem;
left: 1rem;
z-index: 1;
color: #000;
display: flex;
flex-wrap: wrap;
justify-content: center;
}
.progress > input[type="number"] {
text-align: center;
}
.progress > input[type="range"] {
width: 100%;
}
</style>
Search in the book
<script>
import { SvelteReader } from "svelte-reader";
let rendition = null;
let searchText = "只在捻花一笑中";
let searchResults = [];
const search = async () => {
if (!searchText) return (searchResults = []);
const res = await doSearch(searchText);
searchResults = res.slice(0, 5);
};
const doSearch = (value) => {
const { book } = rendition;
return Promise.all(
book.spine.spineItems.map((item) => {
return item.load(book.load.bind(book)).then((doc) => {
const res = item.find(value);
item.unload();
return Promise.resolve(res);
});
})
).then((res) => Promise.resolve([].concat.apply([], res)));
};
const go = (href, e) => {
rendition.display(href);
e.stopPropagation();
e.preventDefault();
};
</script>
<div style="position: relative">
<div style="height: 100vh">
<SvelteReader
url="/files/啼笑因缘.epub"
getRendition={(val) => (rendition = val)}
/>
</div>
<div class="search">
<input
value={searchText}
on:input={(e) => (searchText = e.target.value)}
type="text"
placeholder="search"
on:keyup={(e) => e.key === "Enter" && search()}
/>
<div class="searchResults">
{#each searchResults as item, index}
<div class="item" on:click={(e) => go(item.cfi, e)}>
{@html item.excerpt.trim().replace(searchText, `<span style="color: orange">${searchText}</span>`)}
</div>
{/each}
{#if !searchResults.length}
<div>Empty</div>
{/if}
</div>
</div>
</div>
<style>
.search {
position: absolute;
bottom: 1rem;
right: 1rem;
left: 1rem;
text-align: center;
z-index: 1;
color: #000;
background: #fff;
display: flex;
align-items: center;
justify-content: center;
}
.search .searchResults {
width: 200px;
}
.search .searchResults .item {
cursor: pointer;
border-radius: 4px;
overflow: hidden;
white-space: nowrap;
text-overflow: ellipsis;
border-bottom: 1px solid #000;
}
.search .searchResults .item:hover {
background: rgba(0, 0, 0, 0.05);
}
</style>