Like other expression languages, it can perform mathematical calculations and evaluate logical statements. What makes Arcade particularly unique to other expression and scripting languages is its inclusion of geometry functions. These geometry operations allow you to calculate areas and lengths, test topological relationships, and perform simple overlay operations. Geometry functions introduced in Arcade 1.
The plan was not ridiculously ambitious. This meant automatic indentation and, if possible at all, syntax highlighting.
In this document I describe the story of implementing this, for your education and amusement. A demonstration of the resulting program, along with the source code, can be found at the project website.
Only indentation The very first attempt merely added auto-indentation to a textarea element. It would scan backwards through the content of the area, starting from the cursor, until it had enough information to decide how to indent the current line.
A statement that is continued to the next line is indented one unit more than the line that starts the statement. When dealing with lists of arguments or the content of array and object literals there are two possible models.
If there is any text directly after the opening brace, bracket, or parenthesis, subsequent lines are aligned with this opening character. If the opening character is followed by a newline optionally with whitespace or comments before itthe next line is indented one unit further than the line that started the list.
And, obviously, if a statement follows another statement it is indented the same amount as the one before it. When scanning backwards through code one has to take string values, comments, and regular expressions which are delimited by slashes into account, because braces and semicolons and such are not significant when they appear inside them.
Even though I was working with just a simple textarea at this point, this was already a bit of a headache. On W3C-standards-respecting browsers, textarea nodes have selectionStart and selectionEnd properties which nicely give you the amount of characters before the start and end of the selection.
Then, there is Internet Explorer. Internet Explorer also has an API for looking at and manipulating selections. It gives you information such as a detailed map of the space the selected lines take up on the screen, in pixels, and of course the text inside the selection.
It does, however, not give you much of a clue on where the selection is located in the document. After some experimentation I managed to work out an elaborate method for getting something similar to the selectionStart and selectionEnd values in other browsers.
It worked like this: Get the TextRange object corresponding to the selection. Record the length of the text inside it. Make another TextRange that covers the whole textarea element. Set the start of the first TextRange to the start of the second one.
Again get the length of the text in the first object. Now selectionEnd is the second length, and selectionStart is the second minus the first one. That seemed to work, but when resetting the selection after modifying the content of the textarea I ran into another interesting feature of these TextRanges: Of course, you can count newlines and compensate for this though it is still not possible to position the cursor right in front of a newline.In software engineering, a fluent interface (as first coined by Eric Evans and Martin Fowler) is a method for designing object oriented APIs based extensively on method chaining with the goal of making the readability of the source code close to that of ordinary written prose, essentially creating a domain-specific language within the interface.
An . The new fetch API uses promises and a new syntax for making AJAX requests. fetch is much cleaner than XMLHttpRequest. A set of key/value pairs that configure the Ajax request. All settings are optional. A default can be set for any option with $.ajaxSetup().See pfmlures.com(settings) below for a complete list of all settings.
In this course, you’ll learn what documentation is and why it’s an important part of the development process. You'll learn how to build a well-structured README that you’ll be able to incorporate into your projects moving forward.