Components

from collections import UserDict
from lxml import html as lx
from pprint import pprint

Str and repr

In notebooks, FT components are rendered as their syntax highlighted XML/HTML:

sentence = P(Strong("FastHTML is ", I("Fast")), id='sentence_id')
sentence

<p id="sentence_id">
<strong>FastHTML is <i>Fast</i></strong></p>

Elsewhere, they are represented as their underlying data structure:

print(repr(sentence))

p((strong(('FastHTML is ', i(('Fast',),{})),{}),),{'id': 'sentence_id'})

source

FT.str

FT.str ()

Return str(self).

If they have an id, then that id is used as the component’s str representation:

f'hx_target=#{sentence}'

'hx_target=#sentence_id'

source

FT.radd

FT.radd (b)

'hx_target=#' + sentence

'hx_target=#sentence_id'

source

FT.add

FT.add (b)

sentence + '...'

'sentence_id...'

fh_html and fh_hx

source

attrmap_x

attrmap_x (o)

source

ft_html

ft_html (tag:str, *c, id=None, cls=None, title=None, style=None, attrmap=None, valmap=None, ft_cls=None, **kwargs)

ft_html('a', **{'@click.away':1})

<a @click.away="1"></a>

ft_html('a', {'@click.away':1})

<a @click.away="1"></a>

ft_html('a', UserDict({'@click.away':1}))

<a @click.away="1"></a>

c = Div(id='someid')

ft_html('a', id=c)

<a id="someid" name="someid"></a>

source

ft_hx

ft_hx (tag:str, *c, target_id=None, hx_vals=None, hx_target=None, id=None, cls=None, title=None, style=None, accesskey=None, contenteditable=None, dir=None, draggable=None, enterkeyhint=None, hidden=None, inert=None, inputmode=None, lang=None, popover=None, spellcheck=None, tabindex=None, translate=None, hx_get=None, hx_post=None, hx_put=None, hx_delete=None, hx_patch=None, hx_trigger=None, hx_swap=None, hx_swap_oob=None, hx_include=None, hx_select=None, hx_select_oob=None, hx_indicator=None, hx_push_url=None, hx_confirm=None, hx_disable=None, hx_replace_url=None, hx_disabled_elt=None, hx_ext=None, hx_headers=None, hx_history=None, hx_history_elt=None, hx_inherit=None, hx_params=None, hx_preserve=None, hx_prompt=None, hx_request=None, hx_sync=None, hx_validate=None, hx_on_blur=None, hx_on_change=None, hx_on_contextmenu=None, hx_on_focus=None, hx_on_input=None, hx_on_invalid=None, hx_on_reset=None, hx_on_select=None, hx_on_submit=None, hx_on_keydown=None, hx_on_keypress=None, hx_on_keyup=None, hx_on_click=None, hx_on_dblclick=None, hx_on_mousedown=None, hx_on_mouseenter=None, hx_on_mouseleave=None, hx_on_mousemove=None, hx_on_mouseout=None, hx_on_mouseover=None, hx_on_mouseup=None, hx_on_wheel=None, hx_on__abort=None, hx_on__after_on_load=None, hx_on__after_process_node=None, hx_on__after_request=None, hx_on__after_settle=None, hx_on__after_swap=None, hx_on__before_cleanup_element=None, hx_on__before_on_load=None, hx_on__before_process_node=None, hx_on__before_request=None, hx_on__before_swap=None, hx_on__before_send=None, hx_on__before_transition=None, hx_on__config_request=None, hx_on__confirm=None, hx_on__history_cache_error=None, hx_on__history_cache_miss=None, hx_on__history_cache_miss_error=None, hx_on__history_cache_miss_load=None, hx_on__history_restore=None, hx_on__before_history_save=None, hx_on__load=None, hx_on__no_sse_source_error=None, hx_on__on_load_error=None, hx_on__oob_after_swap=None, hx_on__oob_before_swap=None, hx_on__oob_error_no_target=None, hx_on__prompt=None, hx_on__pushed_into_history=None, hx_on__replaced_in_history=None, hx_on__response_error=None, hx_on__send_abort=None, hx_on__send_error=None, hx_on__sse_error=None, hx_on__sse_open=None, hx_on__swap_error=None, hx_on__target_error=None, hx_on__timeout=None, hx_on__validation_validate=None, hx_on__validation_failed=None, hx_on__validation_halted=None, hx_on__xhr_abort=None, hx_on__xhr_loadend=None, hx_on__xhr_loadstart=None, hx_on__xhr_progress=None, **kwargs)

ft_hx('a', hx_vals={'a':1})

<a hx-vals='{"a": 1}'></a>

ft_hx('a', hx_target=c)

<a hx-target="#someid"></a>

For tags that have a name attribute, it will be set to the value of id if not provided explicitly:

Form(Button(target_id='foo', id='btn'),
     hx_post='/', target_id='tgt', id='frm')

<form hx-post="/" hx-target="#tgt" id="frm" name="frm"><button hx-target="#foo" id="btn" name="btn"></button></form>

source

File

File (fname)

Use the unescaped text in file fname directly

a = Input(name='nm')
a

<input name="nm">

a(hx_swap_oob='true')

<input name="nm" hx-swap-oob="true">

<input name="nm" hx-swap-oob="true">

show

source

show

show (ft, *rest, iframe=False, height='auto', style=None)

Renders FT Components into HTML within a Jupyter notebook.

When placed within the show() function, this will render the HTML in Jupyter notebooks.

show(sentence)

FastHTML is Fast

You can also display full embedded pages in an iframe:

picocss = "https://cdn.jsdelivr.net/npm/@picocss/pico@latest/css/pico.min.css"
picolink = (Link(rel="stylesheet", href=picocss))

fullpage = Html(
    Head(picolink),
    Body(
        H2("Heading 2"),
        P("Paragraph")
    )
)

show(fullpage, height=100, iframe=True)

fill_form and find_inputs

source

fill_form

fill_form (form:fastcore.xml.FT, obj)

Fills named items in form using attributes in obj

@dataclass
class TodoItem:
    title:str; id:int; done:bool; details:str; opt:str='a'

todo = TodoItem(id=2, title="Profit", done=True, details="Details", opt='b')
check = Label(Input(type="checkbox", cls="checkboxer", name="done", data_foo="bar"), "Done", cls='px-2')
form = Form(Fieldset(Input(cls="char", id="title", value="a"), check, Input(type="hidden", id="id"),
                     Select(Option(value='a'), Option(value='b'), name='opt'),
                     Textarea(id='details'), Button("Save"),
                     name="stuff"))
form = fill_form(form, todo)
assert '<textarea id="details" name="details">Details</textarea>' in to_xml(form)
form

<form><fieldset name="stuff">    <input value="Profit" id="title" class="char" name="title">
<label class="px-2">      <input type="checkbox" name="done" data-foo="bar" class="checkboxer" checked="1">
Done</label>    <input type="hidden" id="id" name="id" value="2">
<select name="opt"><option value="a"></option><option value="b" selected="1"></option></select><textarea id="details" name="details">Details</textarea><button>Save</button></fieldset></form>

@dataclass
class MultiSelect:
    items: list[str]

multiselect = MultiSelect(items=['a', 'c'])
multiform = Form(Select(Option('a', value='a'), Option('b', value='b'), Option('c', value='c'), multiple='1', name='items'))
multiform = fill_form(multiform, multiselect)
assert '<option value="a" selected="1">a</option>' in to_xml(multiform)
assert '<option value="b">b</option>' in to_xml(multiform)
assert '<option value="c" selected="1">c</option>' in to_xml(multiform)
multiform

<form><select multiple="1" name="items"><option value="a" selected="1">a</option><option value="b">b</option><option value="c" selected="1">c</option></select></form>

@dataclass
class MultiCheck:
    items: list[str]

multicheck = MultiCheck(items=['a', 'c'])
multiform = Form(Fieldset(Label(Input(type='checkbox', name='items', value='a'), 'a'),
                          Label(Input(type='checkbox', name='items', value='b'), 'b'),
                          Label(Input(type='checkbox', name='items', value='c'), 'c')))
multiform = fill_form(multiform, multicheck)
assert '<input type="checkbox" name="items" value="a" checked="1">' in to_xml(multiform)
assert '<input type="checkbox" name="items" value="b">' in to_xml(multiform)
assert '<input type="checkbox" name="items" value="c" checked="1">' in to_xml(multiform)
multiform

<form><fieldset><label>      <input type="checkbox" name="items" value="a" checked="1">
a</label><label>      <input type="checkbox" name="items" value="b">
b</label><label>      <input type="checkbox" name="items" value="c" checked="1">
c</label></fieldset></form>

source

fill_dataclass

fill_dataclass (src, dest)

Modifies dataclass in-place and returns it

nt = TodoItem('', 0, False, '')
fill_dataclass(todo, nt)
nt

TodoItem(title='Profit', id=2, done=True, details='Details', opt='b')

source

find_inputs

find_inputs (e, tags='input', **kw)

Recursively find all elements in e with tags and attrs matching kw

inps = find_inputs(form, id='title')
test_eq(len(inps), 1)
inps

[input((),{'value': 'Profit', 'id': 'title', 'class': 'char', 'name': 'title'})]

You can also use lxml for more sophisticated searching:

elem = lx.fromstring(to_xml(form))
test_eq(elem.xpath("//input[@id='title']/@value"), ['Profit'])

source

getattr

getattr (tag)

html2ft

source

html2ft

html2ft (html, attr1st=False)

Convert HTML to an ft expression

h = to_xml(form)
hl_md(html2ft(h), 'python')

Form(
    Fieldset(
        Input(value='Profit', id='title', name='title', cls='char'),
        Label(
            Input(type='checkbox', name='done', data_foo='bar', checked='1', cls='checkboxer'),
            'Done',
            cls='px-2'
        ),
        Input(type='hidden', id='id', name='id', value='2'),
        Select(
            Option(value='a'),
            Option(value='b', selected='1'),
            name='opt'
        ),
        Textarea('Details', id='details', name='details'),
        Button('Save'),
        name='stuff'
    )
)

hl_md(html2ft(h, attr1st=True), 'python')

Form(
    Fieldset(name='stuff')(
        Input(value='Profit', id='title', name='title', cls='char')(),
        Label(cls='px-2')(
            Input(type='checkbox', name='done', data_foo='bar', checked='1', cls='checkboxer')(),
            'Done'
        ),
        Input(type='hidden', id='id', name='id', value='2')(),
        Select(name='opt')(
            Option(value='a')(),
            Option(value='b', selected='1')()
        ),
        Textarea(id='details', name='details')('Details'),
        Button()('Save')
    )
)

source

sse_message

sse_message (elm, event='message')

Convert element elm into a format suitable for SSE streaming

print(sse_message(Div(P('hi'), P('there'))))

event: message
data: <div>
data:   <p>hi</p>
data:   <p>there</p>
data: </div>

Tests

test_html2ft('<input value="Profit" name="title" id="title" class="char">', attr1st=True)
test_html2ft('<input value="Profit" name="title" id="title" class="char">')
test_html2ft('<div id="foo"></div>')
test_html2ft('<div id="foo">hi</div>')
test_html2ft('<div x-show="open" x-transition:enter="transition duration-300" x-transition:enter-start="opacity-0 scale-90">Hello 👋</div>')
test_html2ft('<div x-transition:enter.scale.80 x-transition:leave.scale.90>hello</div>')

assert html2ft('<div id="foo">hi</div>', attr1st=True) == "Div(id='foo')('hi')"
assert html2ft("""
  <div x-show="open" x-transition:enter="transition duration-300" x-transition:enter-start="opacity-0 scale-90">Hello 👋</div>
""") == "Div('Hello 👋', x_show='open', **{'x-transition:enter': 'transition duration-300', 'x-transition:enter-start': 'opacity-0 scale-90'})"
assert html2ft('<div x-transition:enter.scale.80 x-transition:leave.scale.90>hello</div>') == "Div('hello', **{'x-transition:enter.scale.80': True, 'x-transition:leave.scale.90': True})"
assert html2ft("<img alt=' ' />") == "Img(alt=' ')"

Components

Str and repr

FT.__str__

FT.__radd__

FT.__add__

fh_html and fh_hx

attrmap_x

ft_html

ft_hx

File

show

show

fill_form and find_inputs

fill_form

fill_dataclass

find_inputs

getattr

html2ft

html2ft

sse_message

Tests

FT.str

FT.radd

FT.add