How to define method chaining in PHP

Question

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PHP method chaining?

I want to use functions combined, like:

select("SELECT * FROM users").where("user=l0 ").join(" . . . ");

How to define this in php?

I feel I should warn you that this kind of thing is a *lot* harder to write than it looks. The simple example you've given won't be hard to achieve, but also won't achieve much (you might just as well write the query as a string). If you want it to do anything clever, it will be a very big project. — Spudley, Nov 01 '12 at 20:00

score 4 · Accepted Answer · edited Nov 01 '12 at 20:34

4

function select(){
     ....
     return new myType;
}

class myType {

     function where(){
         ...
         return $this;
     }

     function join(){
         ...
         return $this;
     }

}

Demo: http://codepad.org/pyrIEW0t

Remember to use -> instead of . in PHP.

This is an example of PHP function chaining.

edited Nov 01 '12 at 20:34

hakre

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answered Nov 01 '12 at 19:51

Naftali

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@user1792423 you don't unless you are just concatting strings (which I do not think you want to do). – Naftali Nov 01 '12 at 20:11

score 1 · Answer 2 · answered Nov 01 '12 at 19:53

The function returns a string and you concatenate the return values of multiple functions.

function select($input) {

//process $input

return $output;

}

function where($input) {

//process $input

return $output;

}

In your php you can call these functions and get the returning result concatenated.

How to define method chaining in PHP

2 Answers2