代写Json、php、Javascritp编程 Google Places API

日期：2018-04-27 02:21

Travel and Entertainment Search Server-side Scripting

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 ipapi.com

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 a

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” dropdown

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 ip-api.com 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 the chosen 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 HTTP requests to the Google

Places API service and display the result in the web page.

The Google Places API is documented here:

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:

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 an HTTP request to the Google Maps Geocoding API, when the location address

is “University of Southern California, CA” is shown below:

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:

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 geo-location around which to retrieve place information. The geo-location is

specified by latitude and longitude values.

? 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 an HTTP request 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 response 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 the 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. The displayed table includes three columns:

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 of an HTTP request to the Google Places API Place Details is shown below:

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 a PHP script 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:

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The request requires providing values for 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 of an HTTP request to the Google Places API Place Photos is shown below:

The response is a binary image file. You should save the top 5 high-resolution photos on the

server side using the function “file_put_contents()”. Figure 8(b) shows a sample response

file.

Figure 8(b): An example of Place Photos query response

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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.

At the top of reviews, you also need to show the name of the selected place.

Note you must only show the photos saved on 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 (i.e., collapsed) (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 shown 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

on the 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 ipapi.com

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 an 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

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 a 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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? Create a project.

? At every Google APIs’ guide page, click “Get a key” and select a created project.

Note that you should NOT use a google account associated with a USC e-mail.

3.2 Google Maps JavaScript API on demand API Documentation

? Adding a Google Map with a Marker to Your Website:

? Directions Service:

3.3 Get geolocation using IP-API.com

You need to use ip-api.com for searching the geolocation based on IP addresses. An example call

looks like:

The response is a JSON object shown in Figure 16.

Figure 16: Response from ip-api.com API

This article introduces some similar APIs, so you have more choice for your hw6 :

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Use of Freegeoip API is not recommended.

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

You can encode data into JSON-formatted objects using the “json_encode” function. For more

information, please go to

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 on the server side, you can use “file_put_contents” function.

**IMPORTANT**:

? You should not use JQuery.

? 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 any one of them in JavaScript instead of PHP will

result in a 4-point penalty.