Skip to content

Latest commit

 

History

History
117 lines (88 loc) · 3.59 KB

TUTORIAL.md

File metadata and controls

117 lines (88 loc) · 3.59 KB
Raw

Tutorial

This tutorial will help you explore a simple use case for Eco. Note that while Eco runs on Python3, it still parses and exports Python2 programs. In order to complete this tutorial, make sure you have also installed Python2.

Installation

Depending on how your version of Python was built, you may need to install SQLite separately. To determine whether you need to do so, run python2 -c "import sqlite3" on your command line. If you get an error message indicating that SQLite is missing on your system, you will need to install SQLite from http://www.sqlite.org/download.html or via your OS's package manager.

You will then need to generate a test database by executing these commands:

  $ wget https://bitbucket.org/softdevteam/eco/downloads/gendb.py
  $ python2 gendb.py

You can then run Eco in the normal way.

Usage

Eco is a language aware editor. When creating a new file we need to specifiy in which language we want to program. Select "File->New" and choose "HTML + Python + SQL" from the list of languages.

We are now writing HTML. Type in the following:

<html>
<head>
</head>
<body>
</body>

At the moment our program is still invalid as shown by the red exclamation mark () under Parsing status on the right-hand-side of the editor.

Let's fix the program by closing the tag. Type:

</html>

Eco incrementally reparses the program on every keystroke. We can see that as soon as we finish typing </html>, the parsing status becomes valid ().

Composed languages

Now we are going to add Python into our HTML program. The grammar we loaded allows for composition of HTML, Python and SQL. Specifically HTML allows Python code wherever it allows html-tags. Move your cursor right after <head> and hit ENTER.

Now hit CTRL+L (or select Edit->Add language box from the menu). From the popup menu select "Python + HTML + SQL". Then type:

    import sqlite3
    c = sqlite3.connect("test.db")

We just created a language box inside of HTML containing Python code.

Let's create another one.

Move you cursor right after <body> hit ENTER and open up the language menu again by hitting CTRL+L. Again select "Python + HTML + SQL" from the list and then type:

    for n, in db:
        print html, n

In this code db and html are placeholders that we are going to replace with further language boxes.

Delete the variable "db", create a new language box using "SQL" and then type:

    SELECT name FROM people;

Afterwards delete the variable "html" and replace it with a language box "HTML" and type:

    <li>

Your code now should look somewhat like this:

Now we can export our program using "File->Export" and saving it as "web.py" (make sure it is saved in the same location where you stored and executed 'gendb.py'). Afterwards we can run it:

    python2 web.py > web.html

Opening the resulting file "web.html" in a browser should now list people from the SQL database.

Non-textual languages

Apart from different programming languages, Eco also has support for non-textual languages. To demonstrate this, we included image support into the HTML+Python+SQL language. Type the following:

<img src= />

Now move the cursor after the = and press Ctrl+L. You will see that one of the highlighted language box options is Image. Select it and press Enter. Now type in the absolute path to an existing image on your harddrive and you should get a result similar to this:

More details at http://soft-dev.org/