How to organize many blocks in one passage? [Twine 2.2.1 / SugarCube 2.21.0]

Question

<<set $curpas = passage()>>

<<if $part == "START">>
Start event description. 
 <<link "Choice 1">>
  <<set $part = "EVENT_1">>
  <<set $param_1 += 10>>
  <<set $param_2 -= 10>>
  <<goto $curpas>>
 <</link>>
 <<link "Choice 2">>
  <<set $part = "EVENT_2">>
  <<set $param_1 -= 10>>
  <<set $param_2 += 10>>
  <<goto $curpas>>
 <</link>>
<</if>>

<<if $part == "EVENT_1">>
Event 1 description.
 <<link "Choice_1_1">>
  <<set $part = "EVENT_1_1">>
  <<set $param_1 += 10>>
  <<goto $curpas>>
 <</link>>
 <<link "Choice_1_2">>
  <<set $part = "START">>
  <<set $param_2 += 10>>
  <<goto "Another passage">>
 <</link>>
<</if>>

<<if $part == "EVENT_2">>
Event 2 description.
 <<link "Choice_2_1">>
  <<set $part = "EVENT_2_1">>
  <<set $param_2 += 5>>
  <<goto $curpas>>
 <</link>>
 <<link "Choice_2_2">>
  <<set $part = "EVENT_2_2">>
  <<set $param_1 -= 7>>
  <<goto $curpas>>
 <</link>>
<</if>>

<<if $part == "EVENT_1_1">>
Event 1_1 description.
 <<link "Next">>
  <<set $part = "START">>
  <<goto "Next passage">>
 <</link>>
<</if>>

<<if $part == "EVENT_2_1">>
Event 2_1 description.
 <<link "Next">>
  <<set $part = "START">>
  <<set $param_2 += 5>>
  <<goto "Next passage">>
 <</link>>
<</if>>

<<if $part == "EVENT_2_2">>
Event 2_2 description.
 <<link "Next">>
  <<set $part = "START">>
  <<set $param_1 -= 10>>
  <<goto "Next passage">>
 <</link>>
<</if>>

Is there more effective method for organization this code?

If I will make passages for each event it will be too many passages (it can be almost hundred events in one passage). With method that I use now it is very hard to find mistakes like missed ">" or "<".

I use links, because I need to change parameters outside of text.

Answer 1

As you have surmised, you generally use either multiple Passages or multiple conditionals statements (, or both methods together) to selectively display content.

note: There is structural issue with how you are using the <<if>> macro in your example.
Because you are using a single $part variable to control which content is shown, and because only one of your <<if>> macros can be true at any one time then all but the first <<if>> macro should be an <<elseif>> macro instead.

<<if $part == "START">>
Start event description. 
...

<<elseif $part == "EVENT_1">>
Event 1 description.
...

<<elseif $part == "EVENT_2">>
Event 2 description.
...

<<elseif $part == "EVENT_1_1">>
Event 1_1 description.
...

<<elseif $part == "EVENT_2_1">>
Event 2_1 description.
...

<<elseif $part == "EVENT_2_2">>
Event 2_2 description.
...

<</if>>

Another possibility is to replace the <<if>> related macros with the <<switch>> macro like so:

<<switch $part>>
<<case "START">>
	Start event description.
	...

<<case "EVENT_1">>
	Event 1 description.
	...

<<case "EVENT_2">>
	Event 2 description.
	...

<</switch>>

warning: both of the above examples have not been tested, they may contain syntax errors. 

Comments

Thank you very much for your answer. <<Switch>> looks more effective than <<if>> in my case.
Is there any advice about debugging in so long passages? Sometimes I look for missing "<" or ">" about half an hour. Even in debbuging mode Twine doesn't show WHERE I missed them.

Or something like this "Error: child tag <</if>> was found outside of a call to its parent macro <<if>>". In long passage with many conditionals statements it's very hard to find where I missed it.

---

The "Debugging" functionality of each story format is implemented by that story format itself, all the Twine 2 application does is ask the story format to switch to debug mode if it has one.

You would need to contact the developer of a particular story format with any suggestions you have with improving its debugging functionality / interface, in your particular case that would be by creating a new issue of the SugarCube project repository's Issues page.

it's very hard to find where I missed it

Code indentation can help with making sure your structure is balanced (eg. start & end tags) and syntax highlighting (if supported) can help with invalid syntax.