Description
1. Objectives
● Get experience with the PHP programming language;
● Get experience with the Google Places API;
● Get experience using JSON parsers in PHP and JavaScript.
2. Description
In this exercise, you are asked to create a webpage that allows you to search for places
information using the Google Places API, and the results will be displayed in a tabular format.
The page will also provide reviews and photos for the selected place.
2.1. Description of the Search Form
A user first opens a page, called place.php (or any valid web page name). You should use the
freegeoip.net HTTP API (See hint 3.3) to fetch the user’s geolocation, after which the search
button should be enabled (it is initially greyed out and disabled when the page loads). The user
must enter a keyword and choose what Category of place he/she wants to search (categories
include cafe, bakery, restaurant, beauty salon, casino, movie theater, lodging, airport, train
station, subway station, bus station) from a drop-down list. The default value for the “Category”
drop-down list is “default”, which covers all of the “types” provided by the Google Places API.
Also, the user can choose the distance (in miles), which is the radius for the search where the
center is “Here” (the current location returned from freegeoip.net HTTP API) or the location
listed in the edit box. When the “Here” radio button is selected, the location edit box must be
disabled. When the location edit box is selected, it is a required field, and a location string must
be entered. The default distance is 10 miles from where the user is or the listed location. Use
HTML5 “placeholder” to show the string “location” in the location edit box and “10” in the
Distance edit box as the initial values. An example is shown in Figure 1.
Figure 1(a): Initial Search Screen (Search button disabled)
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Figure 1(b): Search Screen (after fetched location)
The search form has two buttons:
• Search button: The button must be disabled while the page is fetching the user’s
geolocation and must be enabled once the geolocation is obtained. An example of valid
input is shown in Figure 2. Once the user has provided valid input, your client script should
send a request to your web server script place.php with the form inputs. You can use either
GET or POST to transfer the form data to the web server script. The PHP script will retrieve
the form inputs, reformat it to the syntax of the API and send it to the Google Places API
nearby search service. If the user clicks on the search button without providing a value in
the “Keyword” field or “location” edit box, you should show an error “tooltip” that
indicates which field is missing. Examples are shown in Figure 3a and 3b.
• Clear button: This button must clear the result area (below the search area) and set all fields
to the default values in the search area. The clear operation must be done using a JavaScript
function.
Figure 2: An Example of valid Search
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Figure 3(a): An Example of Invalid Search (empty input)
Figure 3(b): An Example of Invalid Search (empty location)
2.2 Displaying Places Results Table
In this section, we outline how to use the form inputs to construct requests to the Google Places
API service and display the result in the web page.
The Google Places API is documented here:
https://developers.google.com/places/
If the location edit box is selected, the PHP script (i.e. place.php) uses the input address to get
the geocoding via Google Maps Geocoding API. The Google Maps Geocoding API is
documented here:
https://developers.google.com/maps/documentation/geocoding/start
The Google Maps Geocoding API expects two parameters:
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• Address: The street address that you want to geocode, in the format used by the national
postal service of the country concerned. Additional address elements such as business
names and unit, suite or floor numbers should be avoided.
• Key: Your application’s API key. This key identifies your application for purposes of quota
management. (Explained in Section 3.1)
An example of call to the Google Maps Geocoding API, when the location address is “University
of Southern California, CA” is shown below:
https://maps.googleapis.com/maps/api/geocode/json?address=University+of+So
uthern+California+CA&key=YOUR_API_KEY
The response includes the latitude and longitude of the address. Figure 4 shows an example of
the JSON object returned in the Google Maps Geocoding API web service response.
The latitude and longitude of the address, combined with other input information, are needed
when constructing a restful web service URL to retrieve all entities matching the user query,
using the Google Places API “Nearby Search” service, documented here:
https://developers.google.com/places/web-service/search
The Google Places API Nearby Search service expects the following parameters:
• Key: Your application’s API key. This key identifies your application for purposes of quota
management.
• Location: The latitude/longitude around which to retrieve place information. This must be
specified as latitude, longitude.
• Radius: Defines the distance (in meters) within which to return place results. The maximum
allowed radius is 50 000 meters. Note that you need to translate miles to meters for a correct
value.
• Type: Filtering the results to places matching the specified type. Only one type may be
specified (if more than one type is provided, all types following the first entry are ignored).
• Keyword: A term to be matched against all content that Google has indexed for this place,
including but not limited to name, type, and address, as well as customer reviews and other
third-party content.
An example of call to the Google Places API Nearby Search that searches for the nearby cafés
near the University of Southern California within a 10 miles radius is shown below:
https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=34.0223
519,-118.285117&radius=16090&type=cafe&keyword=usc&key= YOUR_API_KEY
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Figure 5 shows an example of the JSON object returned by the Google Places API Nearby
Search web service response. See the documentation on “Search Responses” at the bottom of the
Place Search section in the Google Places API Developer’s Guide at:
https://developers.google.com/places/web-service/search
for the details of the output format returned in search responses.
Figure 4: A sample result of Google Maps Geocoding query
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Figure 5: A sample result of Google Places Nearby Search query
The PHP script (i.e., place.php) should pass the returned JSON object to the client side, or parse
the returned JSON and extract useful fields and pass these fields to client side in JSON format.
You should use JavaScript to parse the JSON object and display the results in a tabular format. A
sample output is shown in Figure 6. There are three columns to be included in the table,
including Category icon, place Name, and place Address. If the API service returns an empty
result set, the page should display “No records have been found” as shown in Figure 7.
Figure 6: An Example of a Valid Search result
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Figure 7: An Example of an Empty Search result
When the search result contains at least one record, you need to map the data extracted from the
API result to render the HTML result table as described in Table 1.
HTML Table Column API service response
Category The value of the “icon” attribute that is part of
the “results” object.
Name The value of the “name” attribute that is part of
the “results” object.
Address The value of the “vicinity” attribute that is part
of the “results” object.
Table 1: Mapping the result from Graph API into HTML table
2.3 Displaying Place Details (Reviews and Photos)
In the search result table, if the user clicks on the name of a place, the page should request the
place details using the Google Places API “Place Details”, documented at:
https://developers.google.com/places/web-service/details
to retrieve reviews and photo references (used to retrieve photos) about the selected place. As
required by Google, this must be done using a server PHP script (i.e., Place.php). The request
needs two parameters (output should be json):
• place_id: an id returned as result of the Google Places API nearby search service
• Key: Your application’s API key. This key identifies your application for purposes of quota
management.
An example call to the Google Places API Place Details is shown below:
https://maps.googleapis.com/maps/api/place/details/json?placeid=ChIJ7aVxnOTHw
oARxKIntFtakKo&key= YOUR_API_KEY
Figure 8(a) shows a sample response.
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Figure 8(a): An example of a Place Details search result (Keyword: USC, Category: default)
Once the PHP script retrieves the response from the Google Places API Place Details query, you
should use PHP to parse the JSON object and use photos’ reference (photo_reference field) to
request high-resolution photos via Google Places API “Place Photos” query, as documented here:
https://developers.google.com/places/web-service/photos
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The request needs three parameters:
• Photo_reference: A string identifier that uniquely identifies a photo. Photo references are
returned from either a Place Search or Place Details request.
• Key: Your application’s API key. This key identifies your application for purposes of quota
management.
• maxheight or maxwidth: specifies the maximum desired height or width, in pixels, of the
image returned by the Place Photos service.
An example call to the Google Places API Place Photos is shown below:
https://maps.googleapis.com/maps/api/place/photo?maxwidth=750&photoreferen
ce=CnRtAAAATLZNl354RwP_9UKbQ_5Psy40texXePv4oAlgP4qNEkdIrkyse7rPXYGd9D_Uj1r
VsQdWT4oRz4QrYAJNpFX7rzqqMlZw2h2E2y5IKMUZ7ouD_SlcHxYq1yL4KbKUv3qtWgTK0A6Qb
Gh87GB3sscrHRIQiG2RrmU_jF4tENr9wGS_YxoUSSDrYjWmrNfeEHSGSc3FyhNLlBU&key=YOU
R_API_KEY
The response is a binary image file. You should save the top 5 high resolution photos at the
server side using file_put_contents(). Figure 8(b) shows a sample response file.
Figure 8(b): An example of Place Photos query response
After retrieving place details data, you can pass the place detail JSON object to the client side
and show the top 5 reviews and top 5 photos in a tabular format.
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At the top of reviews, you also need to show the name of the selected place.
Note you must only show the photos saved at your server machine. Calling directly to Google
Place Photo API at client side is not allowed.
Table 2: Mapping the result from Google Places API into HTML Table
HTML Table Column API service response
Review You should display at most 5 reviews present in
data attribute, which is present in “reviews->text”
attribute. Each review should contain the author
name and author’s profile photo.
Photo You should display at most 5 photos using the
photo_reference, which is present in “photos”
attribute.
The details information includes two sub-sections: Reviews and Photos which are by default
hidden (as shown in Figure 9).
The details information should over-write the result table and needs to be displayed under the
search form. When the user clicks on the button, the “Reviews” sub-section should
be expanded and the “Photos” sub-section should be hidden (if it is open) and vice versa.
Figure 9: Both the reviews and photos are hidden
The “Reviews” sub-section should display the top 5 reviews, as show in Figure 10. Each review
should display the author’s name and his/her profile picture and his/her reviews text.
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Figure 10: When reviews are clicked, photos are hidden.
The “Photos” sub-section should display a maximum of 5 photos (as shown in Figure 11). If any
photo is clicked, it should be opened in a new tab with the original high-resolution photo saved at
server side.
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Figure 11: When photos are clicked, reviews are hidden.
If the API service returns an empty result set, the page should display “No Reviews Found”
instead of review section and “No Photos Found” instead of photo section. A sample output is
shown in Figure 12 and Figure 13.
Figure 12: When no reviews are found.
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Figure 13: When no photos are found.
Note that:
• You must use PHP to request all JSON objects except when calling the
freegeoip.net API which should be called on the client side using JavaScript.
• Expanding or hiding sub areas should be implemented using JavaScript and
you are not allowed to use JQuery.
• High-resolution images must be called using PHP and photos must be saved on
the server-side machine. The client (JavaScript) will access the photos saved on
the server.
2.4 Displaying Map and Directions
In the search result table, when the corresponding address of a certain record is clicked, a Google
Map with a marker of the place should pop up. If the Google Map is already displayed, clicking
it will make the map hidden again. The map should not over-write the result table and needs to
be displayed right under the address that you click on. Please see the video for the details.
You should use the Google Maps JavaScript Library, documented at:
https://developers.google.com/maps/documentation/javascript/adding-a-google-map
to construct the map.
A sample is shown in Figure 14, when selecting the address “699 Exposition Blvd, Los Angeles”
of USC Law School Cafe.
Figure 14: Maps shown when clicking the address of a record.
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At the top left corner of the map, there should be a travel mode list (including Walk there, Bike
there, and Drive there). If a user clicks on any option, the Google Map with a Marker should be
replaced by a Google Map with directions from the location that you choose as the “center point”
on the search form to the selected record on a Google Map. A sample is shown in Figure 15
when choosing “Walk there” based on Figure 14.
You need to use Direction service to construct the direction route map
(https://developers.google.com/maps/documentation/javascript/directions).
Figure 15: the directions after clicking “Walk there”
2.5 Saving Previous Inputs
In addition to displaying the results, the PHP page should maintain the provided values. For
example, if user searches for “Keyword: USC, Category: café, Distance: 15 from Here”, the user
should see what was provided in the search form when displaying the results. In addition, when
clicking on a “Name”, the page should display the reviews/photos and keep the values provided
in the search form. It follows that you need to keep the whole search box/input fields and buttons
even while displaying results/errors.
In summary, the search mechanism to be implemented behaves as follows:
• Based on the query in the search form, construct a web service URL to retrieve the output
from the Google Places API service.
• Pass the (possibly edited) JSON to the client side and parse JSON using JavaScript.
• Display the places information in tabular and chart formats.
• Display the reviews and photos in tabular formats.
• Display the map and directions.
3. Hints
3.1 How to get Google API Key
• To get a Google API key, please follow these steps:
• Go to the Google Developers Console:
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https://console.developers.google.com/flows/enableapi?apiid=geocoding_backend&keyType=SE
RVER_SIDE&reusekey=true
• Create a project.
• At every Google APIs’ guide page, click “Get a key” and select created project.
Note that you should NOT use a google account associated with an USC e-mail.
3.2 Google Maps JavaScript API on demand API Documentation
• Adding a Google Map with a Marker to Your Website:
https://developers.google.com/maps/documentation/javascript/adding-a-google-map
• Directions Service:
https://developers.google.com/maps/documentation/javascript/directions
3.3 Get geolocation using freegeoip.net
An example call to freegeoip.net public HTTP API for searching the geolocation of IP addresses
is shown below, with no parameters required.
http://freegeoip.net/json/
The response is a JSON object including your geo-coordinates. A sample response is shown in
Figure 16.
Figure 16: Response from freegeoip.net API
3.4 Parsing JSON-formatted data in PHP
In PHP 5, you can parse JSON-formatted data using the “json_decode” function. For more
information, please go to http://php.net/manual/en/function.json-decode.php.
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You can encode data into JSON-formatted objects using the “json_encode” function. For more
information, please go to http://php.net/manual/en/function.json-encode.php.
3.5 Read and save contents in PHP
To read the contents of a JSON-formatted object, you can use the “file_get_contents” function.
To save contents at the server side, you can use “file_put_contents” function.
4. Files to Submit
In your course homework page, you should update the Homework 6 link to refer to your new
initial web page for this exercise. Also, submit your source code file (it must be a single .php
file) electronically to the csci571 account so that it can be graded and compared to all other
students’ code via the MOSS code comparison tool.
**IMPORTANT**:
• All discussions and explanations in Piazza related to this homework are part of the
homework description and grading guidelines. So please review all Piazza threads, before
finishing the assignment. If there is a conflict between Piazza and this description and/or
the grading guidelines, Piazza always rules.
• You should not use JQuery for Homework 6.
• You should not call the Google Places APIs (including nearby search service, place
detail service, and place photo service) directly from JavaScript, bypassing the
Apache/HTTP proxy. Implementing anyone of them in JavaScript instead of PHP will
result in a 4-point penalty.
• The link to the video is: https://youtu.be/1uffTsR2jLk
