View Source Phoenix.HTML (Phoenix.HTML v3.3.1)
The default building blocks for working with HTML safely in Phoenix.
This library provides three main functionalities:
- HTML safety
- Form handling (with CSRF protection)
- A tiny JavaScript library to enhance applications
html-safety
HTML safety
One of the main responsibilities of this package is to provide convenience functions for escaping and marking HTML code as safe.
By default, data output in templates is not considered safe:
<%= "<hello>" %>will be shown as:
<hello>User data or data coming from the database is almost never considered safe. However, in some cases, you may want to tag it as safe and show its "raw" contents:
<%= raw "<hello>" %>
form-handling
Form handling
See Phoenix.HTML.Form.
javascript-library
JavaScript library
This project ships with a tiny bit of JavaScript that listens to all click events to:
Support
data-confirm="message"attributes, which shows a confirmation modal with the given messageSupport
data-method="patch|post|put|delete"attributes, which sends the current click as a PATCH/POST/PUT/DELETE HTTP request. You will need to adddata-towith the URL anddata-csrfwith the CSRF token valueDispatch a "phoenix.link.click" event. You can listen to this event to customize the behaviour above. Returning false from this event will disable
data-method. Stopping propagation will disabledata-confirm
To use the functionality above, you must load priv/static/phoenix_html.js
into your build tool.
overriding-the-default-confirmation-behaviour
Overriding the default confirmation behaviour
You can override the default implementation by hooking
into phoenix.link.click. Here is an example:
window.addEventListener('phoenix.link.click', function (e) {
// Introduce custom behaviour
var message = e.target.getAttribute("data-prompt");
var answer = e.target.getAttribute("data-prompt-answer");
if(message && answer && (answer != window.prompt(message))) {
e.preventDefault();
}
}, false);Link to this section Summary
Functions
Escapes an enumerable of attributes, returning iodata.
Escapes the HTML entities in the given term, returning safe iodata.
Escapes HTML content to be inserted a JavaScript string.
Marks the given content as raw.
Converts a safe result into a string.
Link to this section Types
@type safe() :: {:safe, iodata()}
Guaranteed to be safe
@type unsafe() :: Phoenix.HTML.Safe.t()
May be safe or unsafe (i.e. it needs to be converted)
Link to this section Functions
Escapes an enumerable of attributes, returning iodata.
The attributes are rendered in the given order. Note if a map is given, the key ordering is not guaranteed.
The keys and values can be of any shape, as long as they
implement the Phoenix.HTML.Safe protocol. In addition,
if the key is an atom, it will be "dasherized". In other
words, :phx_value_id will be converted to phx-value-id.
Furthermore, the following attributes provide behaviour:
:aria,:data, and:phx- they accept a keyword list as value.data: [confirm: "are you sure?"]is converted todata-confirm="are you sure?".:class- it accepts a list of classes as argument. Each element in the list is separated by space.nilandfalseelements are discarded.class: ["foo", nil, "bar"]then becomesclass="foo bar".:id- it is validated raise if a number is given as ID, which is not allowed by the HTML spec and leads to unpredictable behaviour.
examples
Examples
iex> safe_to_string attributes_escape(title: "the title", id: "the id", selected: true)
" title=\"the title\" id=\"the id\" selected"
iex> safe_to_string attributes_escape(%{data: [confirm: "Are you sure?"], class: "foo"})
" class=\"foo\" data-confirm=\"Are you sure?\""
iex> safe_to_string attributes_escape(%{phx: [value: [foo: "bar"]], class: "foo"})
" class=\"foo\" phx-value-foo=\"bar\""Escapes the HTML entities in the given term, returning safe iodata.
iex> html_escape("<hello>")
{:safe, [[[] | "<"], "hello" | ">"]}
iex> html_escape('<hello>')
{:safe, ["<", 104, 101, 108, 108, 111, ">"]}
iex> html_escape(1)
{:safe, "1"}
iex> html_escape({:safe, "<hello>"})
{:safe, "<hello>"}Escapes HTML content to be inserted a JavaScript string.
This function is useful in JavaScript responses when there is a need to escape HTML rendered from other templates, like in the following:
$("#container").append("<%= javascript_escape(render("post.html", post: @post)) %>");It escapes quotes (double and single), double backslashes and others.
Marks the given content as raw.
This means any HTML code inside the given string won't be escaped.
iex> raw("<hello>")
{:safe, "<hello>"}
iex> raw({:safe, "<hello>"})
{:safe, "<hello>"}
iex> raw(nil)
{:safe, ""}Converts a safe result into a string.
Fails if the result is not safe. In such cases, you can
invoke html_escape/1 or raw/1 accordingly before.
You can combine html_escape/1 and safe_to_string/1
to convert a data structure to a escaped string:
data |> html_escape() |> safe_to_string()