Insert a tag, and check if it is an EuroVOC tag

Choose an open data portal and check how many datasets contain EuroVOC tags

With this functionality is possible count how many dataset in an open data portal contain at least one EuroVOC tag. In the detail page, is possible to see all the datasets and their tags, where are highlighted in green datasets and tags EuroVOC compatible

This example shows how to implement a text input with suggest on EuroVOC tags. The example load all the avaibles tags, in the url used by the ajax call is possible to add filters (eg languages)

Suggests found: 0 - URL used   

How it works

This example uses the javascript plugin typeahead.js and it supposed that the input text has id='suggestText' and the language select has id='suggestLang'

var suggest = $("#suggestText").val();	
var lang = $("#suggestLang").val();								
var suggesttUrl = URL_PROXY_ONTOLOGY+encodeURIComponent("search_text_"+lang+":"+suggest+"*&start=0&rows=20&wt=json");							
suggestText.typeahead({
	source: function( request, response ) {
		$.ajax({ dataType: "json",url: suggesttUrl}).done(function( data ) {
				var suggests = new Array();
				$.each(data.response.docs, function(index, doc) {
					suggests[index] =  doc.term;
				});
				return response(suggests);
			});
		}
	});
									

Due to the same origin policy is not possible via javascript upload the contents of the search query directly in the page. This problem can be easily solved by providing a simple server side proxy that routes the calls

Below is an example of a proxy written in php.

Client - Javascript

// example1:  javascript query url that search  everythings in data and response the first 20 records in json format
var urlDocument = "proxy.php?path="+("documents/select/")+"&params=q=" +encodeURIComponent("*:*&start=0&rows=20&wt=json");

// example2:  javascript query url that search the term water in the ontology and response the first 10 records in json format
var urlDocument = "proxy.php?path="+("ontology/select/")+"&params=q=" +encodeURIComponent("term:water&start=0&rows=10&wt=json");
									
									

Server - Proxy PHP

<?php
  $url = "http://opendata-federation.csi.it/fed-homer/".$_GET['path']."?".$_GET['params'];
  $result = file_get_contents($url);
  // choose the output format 
  if (strpos($url,'wt=xml') !== false) {
	header('Content-type: application/xml');
  } 
  else{
	header('Content-type: application/json');
  }
  echo $result;
?>	
									

This example shows how to create a tag cloud. Via Javascript ask to the Federated Search Engine the statistics on Tag used, than populate a tag cloud.

Load tag url   

Show load tag url proxy   

<div  id='tagCloudPanel'></div>

#tagCloudPanel{
	width: 500px;
	height: 400px;
}

.tag-cloud-item {
	text-align: center;
	padding: .3em;
	font-weight: bold;
}

function loadCloudTags(){
  var tagsArray =  {"Tag": "Count"};
  // the url to get the statistic on tags ordered by count descending
  var action ="*:*&rows=0&facet=true&facet.limit=-1&wt=json&facet.sort=count&facet.field=tag";
  var url_facet = URL_PROXY_DOCUMENTS + encodeURIComponent(action);
  $.ajax({ dataType: "json",url: url_facet}).done(function( data ) {
    var counter = 0;
    var maxCount = 0;
    var minCount = 0;
    // loop on the first 30 records and save the max and the min occourrence
    $.each(data.facet_counts.facet_fields["tag"], function(value, label) {
      if(counter % 2 == 0){
        var count = data.facet_counts.facet_fields["tag"][value+1];
        tagsArray[label]= count;
        if(count>maxCount) maxCount = count;
        if(count font bigger
    var maxFontSize = 32;
    var minFontSize = 4;
    
    var cloudHtml = "";
    counter = 0;
    var tagCloudItems = new Array();
    // prepare the html items for the cloud
    $.each(tagsArray, function(label, count) {
      // the firs row is the labels (tag, count)
      if(counter>0){
        // font size as a percentage of the number of occurrences
        var fontSize = minFontSize+(count-minCount)/(maxCount-minCount)*(maxFontSize-minFontSize);
        tagCloudItems[counter-1] = "<span class='tag-cloud-item' style='font-size:"+Math.round(fontSize)+"px'>"+label+"</span> ";
      }
      counter++;
    });  
    // randomize the tags order!
    tagCloudItems.sort(function() {
      return .5 - Math.random();
    });
    
    // finnally add the tags to the cloud
    $.each(tagCloudItems, function(index, value ) {
      cloudHtml += value;
    });
    
    $("#tagCloudPanel").html(cloudHtml);

  });
}