This page holds an assortment of examples of using Search Element callbacks. They supplement the
examples found in
Callbacks section of the Custom
Search Element API document.
Note:
Executable examples on this page run on the JSFiddle web
site. Look for the jsfiddle button,
, at the
upper right of the code block. Pressing it will open a JSFiddle page with the example displayed
in HTML
, JavaScript
, css
, and run panes. It
starts "alive", so just enter a query in the searchbox shown in the run pane and the callback
runs.
Examples in this document are divided into parts according to their type and function, but:
All the parts of an example are sent to JSFiddle together
Each part of the example has a JSFiddle button. They all do the same thing.
Since this is JSFiddle, you can play with the code. Changes made in JSFiddle are not propagated
back to this document.
Search Starting Callback Examples
The search starting callback can modify the query before it is used for the search.
The Programmable Search Engine can be configured to include pre-determined terms in the query, but
this callback can modify the query based on any information available to the callback
function.
The following search starting callback decorates each query with the current day
of week.
Search Starting Callback Example
<script async
src="https://cse.google.com/cse.js?cx=000888210889775888983:g9ckaktfipe"></script>
const mySearchStartingCallback = ( gname , query ) => {
const dayOfWeek = new Date (). getDay ();
console . log ( dayOfWeek );
var days = {
"0" : "Sunday" ,
"1" : "Monday" ,
"2" : "Tuesday" ,
"3" : "Wednesday" ,
"4" : "Thursday" ,
"5" : "Friday" ,
"6" : "Saturday"
} ;
return query + ' ' + days [ dayOfWeek ] ;
} ;
// Install the callback .
window . __gcse || ( window . __gcse = {} );
window . __gcse . searchCallbacks = {
image : {
starting : mySearchStartingCallback ,
} ,
web : {
starting : mySearchStartingCallback ,
} ,
} ;
Include these elements in the HTML:
<div class="gcse-searchbox"></div>
<div class="gcse-searchresults"></div>
Results Rendered Callback Examples
The results rendered callback is good for modifying the page after it's populated with results.
It is designed to make it easy to modify the display of results without requiring the callback
to take full responsibility for rendering the results.
The following examples illustrate two applications of the results rendered callback that
do not operate on the results.
Identify Last Results Page
This results rendered callback notices that we're displaying the last page
of results, and pops up an alert reminding the user that they've reached the end.
<script async
src="https://cse.google.com/cse.js?cx=000888210889775888983:y9tkcjel090"></script>
myWebResultsRenderedCallback = function (){
var searchresults = document . getElementsByClassName ( "gsc-cursor-page" );
var index = document . getElementsByClassName ( "gsc-cursor-current-page" );
if ( index . item ( 0 ) . innerHTML == searchresults . length ){
alert ( "This is the last results page" );
}
};
Install the callback
window . __gcse || ( window . __gcse = {} );
window . __gcse . searchCallbacks = {
web : {
// Since the callback is in the global namespace , we can refer to it by name ,
// 'myWebResultsRenderedCallback' , or by reference , myWebResultsRenderedCallback .
rendered : myWebResultsRenderedCallback ,
} ,
} ;
Include these elements in the HTML:
<div class="gcse-searchbox"></div>
<div class="gcse-searchresults"></div>
Increasing the font size of the "cursor" links
This results rendered callback demo increases the font size of the
"cursor" numbers that select pages of results.
The default font size is 12px. Here, we increase it to 20px.
<script async
src="https://cse.google.com/cse.js?cx=000888210889775888983:y9tkcjel090"></script>
myWebResultsRenderedCallback = function(){
document.getElementsByClassName("gsc-cursor")[0].style.fontSize = '20px';
};
Install the callback
window . __gcse || ( window . __gcse = {} );
window . __gcse . searchCallbacks = {
web : {
// Since the callback is in the global namespace , we can refer to it by name ,
// 'myWebResultsRenderedCallback' , or by reference , myWebResultsRenderedCallback .
rendered : myWebResultsRenderedCallback ,
} ,
} ;
Include these elements in the HTML:
<div class="gcse-searchbox"></div>
<div class="gcse-searchresults"></div>
Use Letters for "Cursor" Labels
This results rendered callback changes the page links in the "cursor"
from numbers to letters.
<script async
src="https://cse.google.com/cse.js?cx=000888210889775888983:y9tkcjel090"></script>
myWebResultsRenderedCallback = function () {
var arr = document . getElementsByClassName ( 'gsc-cursor-page' );
var alp = [ 'A','B','C','D','E','F','G','H','I','J','K','L',
'M','N','O','p','Q','R','S','T','U','V','W','X','Y','Z' ] ;
for ( var i = 0 ; i & lt arr . length ; i ++ ) {
arr [ i ] . innerHTML = alp [ i ] ;
}
} ;
Install the callback
window . __gcse || ( window . __gcse = {} );
window . __gcse . searchCallbacks = {
web : {
// Since the callback is in the global namespace , we can refer to it by name ,
// 'myWebResultsRenderedCallback' , or by reference , myWebResultsRenderedCallback .
rendered : myWebResultsRenderedCallback ,
} ,
} ;
Include these elements in the HTML:
<div class="gcse-searchbox"></div>
<div class="gcse-searchresults"></div>
Results Ready Callback Examples
Display Results with Alternating-Color Backgrounds
This callback formats results with alternating light and dark backgrounds.
<script async
src="https://cse.google.com/cse.js?cx=000888210889775888983:y9tkcjel090"></script>
Note: This code is written in JavaScript/ES6. It will run on most browsers, but will need
to converted to JavaScript/ES5 for Internet Explorer and a few other older
browsers.
barredResultsRenderedCallback = function ( gname , query , promoElts , resultElts ) {
const colors = [ 'Gainsboro', 'FloralWhite' ] ;
let colorSelector = 0 ;
for ( const result of resultElts ) {
result . style . backgroundColor = colors [ colorSelector ] ;
colorSelector = ( colorSelector + 1 ) % colors . length ;
}
} ;
window . __gcse || ( window . __gcse = {} );
window . __gcse . searchCallbacks = {
web : {
rendered : barredResultsRenderedCallback ,
} ,
} ;
Include these elements in the HTML:
<div class="gcse-searchbox"></div>
<div class="gcse-searchresults"></div>
Word Cloud
The obvious application of the results ready callback is to display search results in
a format that would be hard to reach using the results rendered callback to tweak the
HTML. The results ready callback starts with an empty div
.
One example in the Search Element API document
showed how use the callback to render a very simple version of results.
Another example
showed how to hold the results data from the results ready callback and pass it to
the results rendered callback where it can be used to decorate the standard results
display.
The following results ready callback shows that search results do not have to
be a list of results. It replaces the normal display of search results
with a word cloud of the words found in the results' titles and content. When the list of
results is only an intermediate step for your user, a callback like this can bypass that stage
and use the results to present the report the user wants.
Create a Word Cloud from Search Results Content
<script async
src = "https://cse.google.com/cse.js?cx=000888210889775888983:y9tkcjel090" ></ script >
<style >
# container {
width : 100 % ;
height : 4.5 in ;
margin : 0 ;
padding : 0 ;
}
</ style >
<script src = "https://cdn.anychart.com/releases/v8/js/anychart-base.min.js" ></ script >
<script src = "https://cdn.anychart.com/releases/v8/js/anychart-tag-cloud.min.js" ></ script >
Note: This code is written in JavaScript/ES6. It will run on most browsers, but will need
to be converted to JavaScript/ES5 for Internet Explorer and a few other
older browsers.
const resultsReadyWordCloudCallback = function (
name , q , promos , results , resultsDiv ) {
const stopWords = new Set ()
. add ( 'a' )
. add ( 'A' )
. add ( 'an' )
. add ( 'An' )
. add ( 'and' )
. add ( 'And' )
. add ( 'the' )
. add ( 'The' );
const words = {} ;
const splitter = /[ "“”,\?\s\.\[\ ] \{\} ; :\ - \ ( \ ) \ / !@#\$ % \ ^&*= \ + \ * ] +/ ;
if ( results ) {
for ( const { contentNoFormatting , titleNoFormatting } of results ) {
const wordArray = ( contentNoFormatting + ' ' + titleNoFormatting )
. split ( splitter )
. map ( w => w . toLowerCase ());
for ( const w of wordArray ) {
if ( w && ! stopWords . has ( w )) {
words [ w ] = ( words [ w ] + 1 ) || 1 ;
}
}
}
}
const dataForChart = [] ;
for ( const key in words ) {
const val = words [ key ] ;
dataForChart . push ( {
'x' : key ,
'value' : val ,
} );
}
const container = document . createElement ( 'div' );
resultsDiv . appendChild ( container );
container . id = 'container' ;
// create a tag ( word ) cloud chart
const chart = anychart . tagCloud ( dataForChart );
// set a chart title
chart . title ( ` Words for query : "${q}" ` )
// set an array of angles at which the words will be laid out
chart . angles ( [ 0, 45, 90, 135 ] )
// display the word cloud chart
chart . container ( container );
chart . draw ();
return true ; // Don ' t display normal search results .
} ;
window . __gcse || ( window . __gcse = {} );
window . __gcse . searchCallbacks = {
web : {
ready : resultsReadyWordCloudCallback ,
} ,
} ;
Include these elements in the HTML:
<div class="gcse-searchbox"></div>
<div class="gcse-searchresults"></div>
Two Part Callback Example
The results ready and results rendered callbacks can be used in combination to pass information from the former to the latter.
For example, the information in the array of result objects is available to the results ready callback, but not results rendered callback.
By saving that information to an array as part of the results ready callback we can make it accessible to the results rendered callback.
One example of this is to bypass the preview panel shown when an image result is clicked.
With a two-part callback we can have the image results link directly to the corresponding websites rather than display an image preview when clicked.
Bypass image previews
<script async
src="https://cse.google.com/cse.js?cx=000888210889775888983:g9ckaktfipe"></script>
const makeTwoPartCallback = () => {
let urls ;
const readyCallback = ( name , q , promos , results , resultsDiv ) => {
urls = [] ;
for ( const result of results ) {
urls . push ( result [ 'contextUrl' ] );
}
} ;
const renderedCallback = ( name , q , promos , results ) => {
const removeEventListeners = element => {
const clone = element . cloneNode ( true );
element . parentNode . replaceChild ( clone , element );
return clone ;
} ;
for ( let i = 0 ; i < results . length ; ++ i ) {
const element = removeEventListeners ( results [ i ] );
element . addEventListener ( 'click' , () => window . location . href = urls [ i ] );
}
} ;
return { readyCallback , renderedCallback } ;
} ;
const {
readyCallback : imageResultsReadyCallback ,
renderedCallback : imageResultsRenderedCallback ,
} = makeTwoPartCallback ();
window . __gcse || ( window . __gcse = {} );
window . __gcse . searchCallbacks = {
image : {
ready : imageResultsReadyCallback ,
rendered : imageResultsRenderedCallback ,
} ,
} ;
Include these elements in the HTML:
<div class="gcse-searchbox"></div>
<div class="gcse-searchresults"></div>