What algorithm should I use for a lot of if else(s)?

Question

I have to implement a lot of if else statements and I'm thinking of using Decision Tree but I'm not sure if it's going to be the right algorithm.

I don't want to insert a piece of html code based on these conditions.

directly after an iframe embed (same 300 character rule as columns 4 and 5) directly after a heading tag (same 300 character rule as columns 4 and 5) directly after a facebook embed directly after a twitter embed directly after a vine embed directly after an instagram embed directly after any Oembed directly after an image directly after a video directly after a gallery directly after a protected iframe

So I will scan the whole content of my HTML and try not to add an Ad based on those conditions. The rules will grow as well that's why I don't want to use if else(s).

If I'm missing anything please let me know I will provide more context.

Thanks.

Answer 1

You could use something like this,

Define a rule class where the regex expression to detect the tag is specified, and loop through expressions and insert html where necessary.

class Rule
{
    string tagRegEx;
    string htmlToInsert;
}


public string Process(string html,List<Rule> rules)
{
    //for each rule, check for regex matches and insert the htmlToInsert after 
    return html;
}

Another approach is to use a HTML parser, and use the it's inbuilt function to find nodes and insert your html after them.

Answer 2

As it looks like these are primarily a list of exclusion filters, something like this might get you where you want to be (example in Java, includes calls to functions that probably don't exist as parts of the test):

private static List<Predicate<Node>> AD_FILTERS = Arrays.asList(
  (node) -> node.getPreviousSibling().isIFrame(),
  (node) -> node.getPreviousSibling().isHeading(),
   ...
  (node) -> node.getPreviousSibling().isIFrame() && node.getPreviousSibling().isProtected()
);

...
if (AD_FILTERS.stream().map(filter -> filter.test(node)).allMatch(x -> x == false)) {
  // insert the add
}