Insert content into a file

Contract
Return type	wob
Parameter key	Default value	Type
at_key	"end"	string
Parameter kind	Default value	Type
Other unkeyed arguments	req

Water Contract
<method resource.filesystem.file.insert at_key="end" _other_unkeyed=req=wob=ekind.code="_body"/>

See also: append, set, is_writable, file

Works similar to insert on strings, inserting the _other_unkeyed args into the content of the _subject of type file . The new content of the file is returned. If a location is not specified, it appends content at the end of the file. If an arg is not already a string, it is converted before it is written to the file. If the file is not writable, insert will throw an error.

Example: Insert at end of file (default)

<class foo>
<method htm_inst>
  "foo htm instance"
</method>
</class>
<file "logical://user/test_file.txt" />.<insert <join char.carriage_return char.newline <foo /> /> />

Example: Insert at beginning of file

<class foo>
<method htm_inst>
  "foo htm instance"
</method>
</class>
<file "logical://user/test_file.txt" />.<insert at_key=0 <join  <foo /> char.carriage_return char.newline /> />

Example: Insert at a specified location

<set the_file=<file "logical://user/protected folder/test_file.txt" /> />
<set the_content=the_file.content />
<set the_location=the_content.<key_of char.newline /> />
<set the_location=
<if> the_location.<is false />
       0
     else
       the_location.<plus 1 />
</if>
/>
the_file.<insert at_key=the_location <join  "second line" char.carriage_return char.newline /> />

The example above finds the second line of the text file and inserts the text "second line" in front of it. Each of the examples above would return the new contents of the specified file if the file is writable.