fixing pagination limit on javascript

Question

first of all, to be clear i am a newbie with javascript and jquery. now, i am using a javascript file to paginate inside a div. the script works fine, but if there is a lot of data then i need to limit the paginating links with a "next" and a "previous" tag. i can't find a way to do that. currently the pagination script is showing all the numbers like 1 2 3 4 5 6 7 8 9 etc depending on the data supplied. but, i want to show them like, 1 2 3 4 5 next>> or, <<prev 2 3 4 5 6 next>>

here is my pagination.js

var Imtech = {};
Imtech.Pager = function() {
    this.paragraphsPerPage = 3;
    this.currentPage = 1;
    this.pagingControlsContainer = "#pagingControls";
    this.pagingContainerPath = "#content";

    this.numPages = function() {
        var numPages = 0;
        if (this.paragraphs != null && this.paragraphsPerPage != null) {
            numPages = Math.ceil(this.paragraphs.length / this.paragraphsPerPage);
        }

        return numPages;
    };

    this.showPage = function(page) {
        this.currentPage = page;
        var html = "";
        for (var i = (page-1)*this.paragraphsPerPage; i < ((page-1)*this.paragraphsPerPage) + this.paragraphsPerPage; i++) {
            if (i < this.paragraphs.length) {
                var elem = this.paragraphs.get(i);
                html += "<" + elem.tagName + ">" + elem.innerHTML + "</" + elem.tagName + ">";
            }
        }

        $(this.pagingContainerPath).html(html);

        renderControls(this.pagingControlsContainer, this.currentPage, this.numPages());
    }

    var renderControls = function(container, currentPage, numPages) {
        var pagingControls = "<b>Pages</b>: <ul>";
        for (var i = 1; i <= numPages; i++) {
            if (i != currentPage) {
                pagingControls += "<li><a href='#' onclick='pager.showPage(" + i + "); return false;'>" + i + "</a></li>";
            } else {
                pagingControls += "<li>" + i + "</li>";
            }
        }

        pagingControls += "</ul>";

        $(container).html(pagingControls);
    }
}

to get the desired look, how do i edit this script?if anyone could help me with it, please do so.

Answer 1

You could change renderControls like this:

var renderControls = function(container, currentPage, numPages, pagesCutoff) {
    var pagingControls = "<b>Pages</b>: <ul>";
    var prevPosition = currentPage - pagesCutoff;
    var nextPosition = currentPage + pagesCutoff;

    for (var i = 1; i <= numPages; i++) {
        if (i != currentPage) {                
            if(i >= prevPosition && i <= nextPosition) {
                var linkToPage = i == prevPosition ? currentPage - 1 : i == nextPosition ? currentPage + 1 : i;
                var linkText = i == prevPosition ? "<< prev" : i == nextPosition ? "next >>" : i;

                pagingControls += "<li><a href='#' onclick='pager.showPage(" + linkToPage + "); return false;'>" + linkText + "</a></li>";
            }
        } else {
            pagingControls += "<li>" + i + "</li>";
        }
    }

    pagingControls += "</ul>";

    $(container).html(pagingControls);
}

And add this to Imtech.Pager: this.pageLinksEachSide = 3;

And change the renderControls call to this: renderControls(this.pagingControlsContainer, this.currentPage, this.numPages(), this.pageLinksEachSide);

This is assuming that you want the "next" link to navigate to currentPage + 1 and the "prev" link to navigate to currentPage - 1.