//The script will hide posts with TEXT_FLAG in their tags (tags != source, fyi)
var TEXT_FLAG = "father";

//Adds contains to String prototype,
//returns true if string contains substring
String.prototype.contains = function(it) { return this.indexOf(it) != -1; };

//list = all <li>, posts are contained there
//list_array = just id numbers for posts
var list = document.getElementsByTagName('li');
var list_array = new Array();

//populate array with every post id
for (var i = 0, length = list.length; i < length; i++) {
    if( /post_[\d]+/.test(list[i].id) ){
        var id_number = list[i].id.split(/_/)[1];
        list_array.push(id_number);
    }
}

//cycle posts ids in array, search tags, if tags match TEXT_FLAG, hide element
for(var i = 0, length = list_array.length; i < length; i++){
    var tag = document.getElementById("post_tags_"+list_array[i]);
    if(tag){
        var tags = tag.getElementsByTagName("a");
        for(var j = 0, length = tags.length; j < length; j++){
            tag_text = tags[j].text;
            if( tag_text.contains(TEXT_FLAG) ){
                //console.log(tags[j].text);
                var content = document.getElementById("post_"+list_array[i])
                content.style.visibility = "hidden";
            }
        }
    }
}