Syntax similar to JSX

[Archmonger]

Current Situation

ReactJS has a method of HTML templating called JSX. We currently do not have an equivalent. We need to create a Python-based JSX equivalent that operates similarly to how it is used in ReactJS (Javascript).

The key difference here is we will not use a dedicated file extension (such as .psx) in order to not break existing toolchains. Instead, we will rely on the tag string PEP that adds template literals to Python. Here is an example of the tag string syntax:

from reactpy import html

button_style = {"font_style": "bold"}
button_text = "Click me!"
view = html(t"<button on_click={lambda event: ...} style={button_text}>{button_text}</button>")

While we wait for the tag string PEP to be merged, we could potentially use an interim transpiler to use a similar syntax. The interim transpiler syntax would look something like this:

from reactpy import html

button_style = {"font_style": "bold"}
button_text = "Click me!"
view = html @ f"<button on_click={lambda event: ...} style={button_text}>{button_text}</button>"

Proposed Actions

Aid in the development of this proposed transpiler and then develop an html tag function. An initial implementation of an html tag can be found here.

[bitnom]

If a transpiler is required to get the same sort of syntax as JSX, then how would template literals be any better than fstrings?

[rmorshea]

The main purpose of template literals is to have a dedicated syntax. Transpilers allow you to write any syntax you'd like in your Python files, and at least for JSX, that's already been done. The problem, and the reason I suspect Pyxl never saw wide adoption, is because it breaks all the tools you would normally use with a Python file (e.g. black, flake8, pylint, mypy, the list goes on...). You could as I proposed above, co-opt an existing syntax which is seen infrequently (e.g. tag @ f"..."), but without standardization, no one is going to create tooling that understands that bespoke syntax and provides highlighting and auto-completions.

[rmorshea]

I've published an import-time transpiler that implements that aforementioned tag string spec.

$ pip install tagstr

# tagstr: on
name = "world"
print @ f"hello {name}!"

hello  (<function <lambda> at 0x7f7a8586b920>, 'name', None, None) !

I don't think this is ready for production yet, but with some more work behind this I think it provides a promising alternative to the current, and rather disjointed, patterns for constructing views in ReactPy. Integrating this into ReactPy could also act as a compelling real-world use case for the Tag String PEP itself.

[mtrunkbear]

That could be PSX python syntax extension, or PYX python XML

[mtrunkbear]

@rmorshea Very good work bro, i was reading the tag string docs and tutorial and i think that is a very useful aproximation.

[aranega]

Just for the sake of "state of the art", there is also this project named packed that is similar to pyxl3, but the syntax looks a little bit more like like tsx syntax on some small aspects. I guess the same criticisms apply to this project about the lake of syntax highlight,...

[zx013]

I use BeautifulSoup analyse xml, then it can work below.

@component
def DataList(items, functest=None, filter_by_priority=None, sort_by_priority=False):
    if filter_by_priority is not None:
        items = [i for i in items if i["priority"] <= filter_by_priority]
    if sort_by_priority:
        items = sorted(items, key=lambda i: i["priority"])
    list_item_elements = [f"""<li key="{i["id"]}">{i["text"]}</li>""" for i in items]
    test = "<sdfa>"
    return """
        <ul>
            abcdedfe
            {functest()}
            {"".join(list_item_elements)}
            {test}
            {test}
            def
            ""{""}""
            <div>test</div>
        </ul>
    """

@component
def TodoList(text=""):
    def functest():
        return ("test-----------------------abc")
    tasks = [
        {"id": 0, "text": f"{text} Make breakfast3", "priority": 0},
        {"id": 1, "text": f"{text} Feed the dog", "priority": 0},
        {"id": 2, "text": f"{text} Do laundry", "priority": 2},
    ]
    return """
        <section>
            <h1>My Todo List</h1>
            <DataList items={tasks} functest={functest} filter_by_priority={1} sort_by_priority={True} />
        </section>
    """

@component
def Test():
    a = 2
    b = 3
    return """
        <h1 id="1" class_name="abc">My Todo List {a + b} Test PSX</h1>
        <ul id="2">
            <li id="5">"Design {23} a cool new app</li>
            <li id="4">Build"</li>
            <li>"Share it with the world!</li>
        </ul>
        <TodoList class_name="abc" />
        <TodoList text="abcd">
            <div>abc</div>
        </TodoList>
        <img
            src="https://picsum.photos/id/237/500/300"
            class="img-fluid"
            style="width: 50%; margin-left: 25%;"
            alt="Billie Holiday"
            tabindex="0"
        />
    """

[hasansezertasan]

There is a project that this issue brought to my mind.

RudreshVeerkhare/ReactPy: React implementation in Python 3, which runs on the client-side.

I have never used this project, but I have examined its examples. It allows creating files with the .pyx extension and in these files, you can write HTML with Python, without doing any string formatting.

And I also want to highlight these resources:

• React in Python with Pyodide | Pyodide blog
• Packed: a JSX-style syntax preprocessor for Python : Python
• jviide/htm.py: JSX-like syntax in plain Python

And finally, I love Python syntax and hate micro-syntaxes (Jinja counts).

[zx013]

There is a project that this issue brought to my mind.

RudreshVeerkhare/ReactPy: React implementation in Python 3, which runs on the client-side.

I have never used this project, but I have examined its examples. It allows creating files with the .pyx extension and in these files, you can write HTML with Python, without doing any string formatting.

And I also want to highlight these resources:

• React in Python with Pyodide | Pyodide blog
• Packed: a JSX-style syntax preprocessor for Python : Python
• jviide/htm.py: JSX-like syntax in plain Python

And finally, I love Python syntax and hate micro-syntaxes (Jinja counts).

ReactPy is client side but reactpy is server side. There are two ways to analyze pyx, BeautifulSoup and pypeg2. Then how to use js/ts. component library may be important, reactpy get the easy way get it.

[hasansezertasan]

ReactPy is client side but reactpy is server side. There are two ways to analyze pyx, BeautifulSoup and pypeg2. Then how to use js/ts. component library may be important, reactpy get the easy way get it.

Yep, thanks for informing 🤩.