Requires Analytica Enterprise 4.2. Unsupported function at this time.

ReadFromUrl(url)

Reads a page or text file from the given URL and returns the result as a text value.

Using this function, you can read from an HTTP or HTTPs page (e.g., web page or secure web page), from FTP, or from GOPHER. You can also submit data as would occur on a web page when a user submits an HTTP form. The content retrieved must be text. It can also be used to "call" web services to obtain data. The data is returned as a text value, so in general, you will need to use other Analytica functions to parse the data.

There are several optional parameters that may be useful in various context.

Reading from a Web page

To obtain the contents of a web page, which is usually in HTML format, just supply the URL, e.g.:

ReadFromUrl("http://lumina.com")

If you leave off the "http://" part, it defaults to an http query, e.g.:

ReadFromUrl("lumina.com")

Submitting Data to a Web Page

To simulate the submission of HTML form data when querying a web page, you can either submit the information using GET or POST methods. With a form uses a GET method, you would normally see the parameters appear on the URL itself. With a POST method, you would normally not see the parameters -- they would be passed in the body of the HTTP request.

To submit form data, you need to set up an array of fields and an array of field names. The fields and field names need to share a common index. A common way to do this is to create the field names index as a list-of-labels, and then create a table based on this index for the fields. The function call uses these parameters:

ReadFromUrl(url,method,formValues,formFields,formIndex)

The «formIndex» parameter is the index that «formValues» and «formFields» have in common. When it is guaranteed that there will be only one index in common, such as when «formFields» is an index, then the «formIndex» parameter is unnecessary.

For example, the following queries Google for "Analytica":

Index fieldNames := ["hl","q"];
Var form := Array(fieldNames,["en","Analytica"];
ReadFromUrl("http://google.com/search","GET", form,fieldNames)

The result obtained is in HTML format.

You do not have to worrying about URL-encoding the field names or values. If there are non-alpha numeric characters in either, they will be encoded before they are submitted.

Obtaining text content from an FTP site

To obtain content from an FTP site, use:

ReadFromUrl("ftp://site.com/directory/file.txt")

Keep in mind that the content must be textual. Binary files will be corrupted as they are read into a text value (specifically, '\0' characters will be converted to spaces).

Authentication

FTP sites commonly require user and password authentication, as is also common for web services and some web pages. To authenticate, embed the user name and password in the URL as follows:

ReadFromUrl("http://user:password@www.site.com/dir/page.htm")

ReadFromUrl("ftp://user:password@www.site.com/dir/page.htm")

Sending data CGI scripts and proprietary web services

If you call a CGI service, the CGI program will accept input in its own format, which could be arbitrary. You can send this data as follows:

ReadFromUrl("http://server.com/cgi-bin/myProgram.cgi",content:data)

In this example, data contains the data that you are submitting to the CGI script. This data will form the body of the HTTP request. Content may only be used with HTTP requests, not with FTP or Gopher requests.

Various web services fall into this category as well, where data being submitted via HTTP may be in a proprietary format.

In some cases, you may also need to include additional HTTP headers in your request. You can insert these using the optional «httpHeaders» parameter. If you have more than one HTTP header, separate them using a CR character, Chr(13). If you enter these into a definition (e.g., with quotes), you can just type a new line, or if you enter them into a single edit table cell, pressing ALT-ENTER to insert a CR (new-line) into the cell. Otherwise, you can use the & operator to concatenate each header line with Chr(13).

ReadFromUrl("http://somehost.com",httpHeaders:"Accept:text/xml"&Chr(13)&"User-Agent:MyModel.ana")

ReadFromUrl

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